EPA-600/2-76-263
December 1976
Environmental Protection Technology Series
                            A  RIGID,  PERFORATED  PLATE
                         OIL  BOOM  FOR  HIGH  CURRENTS
                                     Industrial Environmental Research Laboratory
                                           Office of Research and Development
                                          U.S. Environmental Protection Agency
                                                   Cincinnati, Ohio 45268

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                RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency,  have been grouped  into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4.    Environmental Monitoring
     5.    Socioeconomic Environmental Studies

This report has been assigned  to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control  and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                                   EPA-600/2-76-263
                                                   December 1976
           A RIGID, PERFORATED PLATE OIL BOOM

                    FOR HIGH CURRENTS
                      R. R. Ayers
                Shell Development Company
                  Houston, Texas 77035
                       68-03-0331
                     Project Officer
                     John S. Farlow

Oil and Hazardous Materials Spills Branch (Edison, N.J.)
      Industrial Environmental Research Laboratory
                 Cincinnati, Ohio 45268
      INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
           OFFICE OF RESEARCH AND DEVELOPMENT
          U.S. ENVIRONMENTAL PROTECTION AGENCY
                 CINCINNATI, OHIO 45268

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                            DISCLAIMER
     This report has been reviewed by the Industrial Environmental
Research Laboratory—Cincinnati, Ohio, U.S. Environmental Protection
Agency, and approved for publication.  Approval does not signify that
the contents necessarily reflect the views and policies of the U.S.
Environmental Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
                                  ii

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                              FOREWORD
     When energy and material resources are extracted, processed, con-
verted, and used, the related pollutional impacts on our environment
and even on our health often require that new and increasingly more
efficient pollution control methods be used.  The Industrial Environy
mental Research Laboratory - Cincinnati (lERL-Ci) assists in develop-
ing and demonstrating new and improved methodologies that will meet
these needs both efficiently and economically.

     This report describes an improved boom capable of directing spills
of oil or floating hazardous materials toward shore in a 3-knot  (1.5
m/s) river or tidal current.  This capability is about double that of
conventional booms.  The applied research leading to its development
and the confirming tests of its capability at EPA's OHMSETT facility
are also described.  Detailed information and construction drawings
are provided to enable anyone with a need to protect high current
streams from spills to build a duplicate boom for their own use, and
to enable researchers with related interests to follow the develop-
mental rationale.  For additional information, please contact the
U.S. EPA Oil and Hazardous Materials Spills Branch, Edison, N. J.
08817.
                                  David G. Stephan
                                      Director
                   Industrial Environmental Research Laboratory
                                     Cincinnati
                                  ixi

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                                   ABSTRACT

     A boom capable of diverting oil spills toward shore in a 3-knot (1.5 m/s)
river or tidal current has been developed.  Loss of No. 2 and No. 4 Fuel Oil
at this velocity is typically less than 15 percent when the angle of the boom
is 45 degrees to the shoreline.  In contrast, conventional booms lose this
amount at only 1 knot (0.5 m/s).

     Good performance at high currents is achieved by placing a baffle upstream
of a conventional flat plate boom.  The baffle, an inclined, perforated plate,
is used to create a flow-sheltered region where the oil layer thickens.  A
continuation of the inclined plate baffle forms the "floor" of the sheltered
region to control the flow rate of exiting water.  Horizontal plates immedi-
ately behind the baffle reduce water down-flow.

     The boom is made up of 8-foot (2.4 m) long, rigid sections similar in
plan view to a floating dock module.  The length of the boom depends upon the
number of modules pinned together side by side.  Floating suction or sorbent
rope collection devices may be used to remove accumulated oil from the flow
sheltered region and increase "capacity".

     One or more modules can also be attached to vessels of opportunity and
used as a skimmer.

     Construction drawings are included with this report.

     This report was submitted in fulfillment of Program Element No. 1BB041,
Contract Number 68-03-0331 by Shell Development Company under the sponsorship
of the Environmental Protection Agency.  Work was completed as of May  1976.
                                      IV

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                             TABLE OF CONTENTS
Foreword

Abstract

List of Tables

List of Figures                                                         viii

Acknowledgements                                                        x

   I.  Introduction                                                         1

  II.  Conclusions                                                          2

 III.  Recommendations                                                      3

  IV.  Rigid, Perforated-Plate Boom Design Summary                          4
         Description                                                        4
         Performance in Currents                                            4
         Performance in Waves and Debris                                    5
         Oil Recovery Techniques                                            5
         Applications                                                      17

   V.  Discussion of the problem                                           20
         The Problem                                                       20
         Limitations of Conventional Booms                                 22
         Previous Shell Investigations                                     30
         Investigations of Others                                          31

  VI.  Initial Baffle Studies                                              37
         Introduction                                                      37
         Summary                                                           40
         Stub-Tube Baffle Experiments                                      40
         Perforated-Plate Baffle Experiments                               45
         Preliminary Tow Tests - Perforated-Plate Boom Concept             45

 VII.  Confirming Tests                                                    54
         Tow Tests - Houston                                               54
         Three-Dimensional Tow Tests - OHMSETT                             55

                                      v

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                         TABLE OF CONTENTS (cont'd.)
VIII.  References

  IX.  Appendices
         A.  Details of stub-tube baffle experiments.
         B.  Details of perforated-plate baffle experiemnts.
         C.  Summary of perforated plate tow tests.
         D.  Three dimensional tow tests - Houston.
         E.  OHMSETT test facility.
         F,  Additional test information - OHMSETT tests.
         G.  English-Metric Conversion table.
                                      VI

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                                LIST OF TABLES




Table                                                                   Page




  1     Perforated Plate Tow Tests                                         48




  2     Two-Dimensional Boom Tow Tests                                     58




  3     Measured Test Oil Properties - Shell Tests                         59




  4     Measured Test Oil Properties - OHMSETT Tests                       63




  5     Results - High Current Boom Tests at OHMSETT                       64
                                     vii

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                                LIST OF FIGURES




Figure                                                                   Page





   1      Photograph of Boom in EPA OHMSETT Tests                           6




   2      Photograph of Boom in EPA OHMSETT Tests                           7




   3      Boom Modules Side by Side                                         8




   4      Four-Foot Wide High Current Boom Test Section                     9




   5      Profile of the Rigid, Perforated Plate Boom                      10




   6A     EPA High-Current Boom - Plan & Elevation                         13




   6B     EPA High-Current Boom - Bottom Plate & Details                   15




   7      Predicted Performance of High-Current Boom                       11




   8      Example  of  Means to Recover Oil                                 16




   9      Plan View of High Current Boom                                   18




  10      Emergency Self-Propelled Skimmer                                 18




  11      Two Permanent Skimmer Configurations                             19




  12      Containment and Diversion in River Currents                      21




  13      Conventional Boom Containing Spilled  Oil                        23




  14      Oil Set-Up in Front of a Barrier                                 24




  15      Minimum Boom Skirt Draft for Containment                         26




  16      Histogram of Oil Loss from Coast Guard Boom Tow Tests            28




  17      Critical Velocity for Oil Loss and Diversion                     29




  18      First High-Current Boom Model by Shell                           30




  19      Revised Baffle Concept                                           32




  20      A Preliminary Configuration for Project  Sea Dragon               33






                                    viii

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                           LIST OF FIGURES  (cont'd)
Figure                                                                   Page

  21      Double-Boom Concept Tested by Atlantic Research Corp.            33
  22      Ocean Systems Dynamic Keel Concept                               34
  23      JBF Fixed  Inclined Plane Concept                                 34

  24      Pace Flexible Double Boom Concept                                36
  25      Initial Baffle Candidates for the Shell Study                    38
  26      Shell Current Tank Facility                                      39
  27      Optimum Inclined Plate Baffle Boom Arrangement                   42
  28      Tentative  Optimum .Stub-Tube-Baffle Boom Arrangement              43
  29      Test Set-Up of Stub-Tube Array  in Current Tank                   44
  30      Photographs of Tow 2-D Test Model (Full Scale)                   47
  31      Test Configurations                                              50
  32      Final Boom Configuration Before Flotation is Added               53
  33      Boom Test  Set-Up Houston in Wave/Tow  Tank                        56
  34      Boom Section During Tow Testing                                 57
  35      Sketch of  Boom Mooring System Used for OHMSETT Tests             60
                                      IX

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                                 ACKNOWLEDGEMENTS
          Shell appreciates the opportunity to conduct this interesting
project for the EPA.  For his helpful advice during the program and his
assistance in reviewing the draft manuscripts, we thank Mr. John S. Farlow,
Project Officer.

          To our valuable technicians, Jim Smith, Dean Henning, and Bob
Hammond, who made the prototype work well, we also offer thanks.
                                     x

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                           I.  INTRODUCTION

     The most effective way of controlling the movement of oil spilled
on water is to use floating oil barriers, or booms.   Although booms have
been significantly improved in recent years, a fundamental problem re-
mains in containing and diverting oil in high currents.  Many of our
rivers and tidal estuaries have currents in excess of two knots and con-
ventional booms do not perform well at such velocities.

     A radically different rigid, modular boom has been designed and
verified by test for permanent installation in high currents.  The design
is based upon placing a baffle immediately upstream of a barrier to slow
down the surface flow and, as a consequence, contain oil between at
higher currents than conventional booms.

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                               II.   CONCLUSIONS

1.  A high-current boom capable of  diverting No.  2  and  No.  4  fuel  oil to shore
    at 3 knots (1.5 m/s) with typically less than 15  percent  of  the applied
    oil loss under the boom has been developed by Shell with  funding from the
    U.S. Environmental Protection Agency (EPA).

2.  This boom design depends upon an inclined, 50 percent perforated-plate
    baffle just upstream of a solid vertical-plate  barrier.   The flow-sheltered
    region between the baffle and the barrier has a perforated plate as  a
    bottom, slowing the exiting water.   In addition,  horizontal  flow control
    plates immediately behind the inclined baffle reduce water downflow  and
    minimize turbulence.

3.  The boom profile is built into  8-foot (2.4 m) wide  rigid  sections and
    linked together like a floating marina dock.

4.  A primary application for this  high-current device  is its use  as a perma-
    nently deployed diversionary boom,  perhaps downstream of  an  oil loading/
    unloading dock.  A standard skimmer,  used in  the  flow-sheltered region of
    the boom to recover oil accumulated,  will increase  the boom's  effectiveness.

5.  Boom modules can be attached to vessels of opportunity  for use as a  tempo-
    rary emergency skimmer.  They can also be placed  in a specially designed
    vessel and used as a permanent  inshore skimmer.

6.  The boom design is based on extensive full-scale  experimentation and test-
    ing at the Shell current and wave tanks.  Principal confirming tests were
    conducted at the EPA's OHMSETT  Facility.

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                             Ill.   RECOMMENDATIONS

1.  A single boom module should be fabricated according to the field-type
    design resulting from this program.  The module,  a "heavy-duty"  version
    of that testfed, should be tow-tank tested to make a final check  of the
    flotation/weight and adequacy of the design (Figures 6a and 6b).   Minor
    corrections should be made if needed.

2.  Additional modules should then be fabricated and  installed (pinned together
    to obtain the total length needed) in at least one suitable field location
    where boom performance can be evaluated in a real-life situation.

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               IV.  RIGID, PERFORATED-PLATE BOOM DESIGN SUMMARY

DESCRIPTION

     The forty-foot-long high-current boom section shown during tank testing
in Figures 1 and 2 is a major result of a development program conducted by
the Pipeline Research and Development Laboratory of Shell Development Company
for the Industrial Environmental Research Laboratory of the U.  S.  Environmen-
tal Protection Agency under Contract Number 68-03-0331.

     The rigid boom is formed by joining modules side-by-side (Figure 3).  A
typical four-foot wide module is shown in Figure 4.  Design features are
revealed in Figure 5.  Upstream of a conventional flat-plate barrier the
design incorporates a perforated-plate baffle to absorb part of the kinetic
energy of water flow that a barrier alone normally experiences.  A reduced-
velocity region is created between the upstream perforated plate baffle and
the downstream barrier.  In a 3-knot (See English-Metric Conversion Table,
Appendix G) free-stream current, for instance, currents of less than 0.6
knots have been measured in the reduced velocity region.  Because loss of oil
past a barrier is a function of the local velocity, oil does not easily
escape under this barrier.

     Streamlined flotation incorporated in the forward part of the profile
and flotation aft of the rear barrier combine to achieve the proper still-
water alignment of the boom.  A planing, perforated bow adds to the dynamic
stability of the boom in combined waves and currents.  Approaching oil read-
ily enters the 50 percent open-area bow and flows into the reduced velocity
region, rather than escaping under the boom.  Once inside the reduced-
velocity region, oil thickens to facilitate removal operations.  Contained
water exhausts downward through a 20 percent open-bottom closure plate.

PERFORMANCE IN CURRENTS

     Based on extensive full-scale testing both at Shell's wave-tow tank in
Houston, Texas and EPA's OHMSETT facility in Leonardo, New Jersey, we recom-
mend the design summarized in Figure 6 for field applications.  This design
differs from that tested only in strength, durability and handleability con-
siderations.

     Figure 7 contains performance data for a high-current boom based on se-
lected tank test results.   In certain cases extrapolations are made to cover
a larger range of spilled oils.   More detailed results are included in Sec-
tion VII.

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     The final design evolved from a careful analysis using flow diffusion
and boom diversion principles to enhance the control of spilled oil in high
currents.  Initially two specific flow diffusion concepts were investigated:
an inclined, perforated plate baffle and a stub-tube array baffle.   In
the experimental program each concept was evaluated and systematic  alter-
ations were made reflecting what was learned from previous tests.   This
interactive "feedback" process yielded somewhat optimized configurations
for the two concepts.  The inclined, perforated plate baffle - quite
different looking from the initial concept - proved to be the better
baffle-boom of the two for high currents.  Descriptions of these basic
experimental studies are found in Section VI.

PERFORMANCE IN WAVES AND DEBRIS

     Test data described in Section VI indicate that small choppy waves,
having periods of up to 2 seconds have only minor effect on the percent-
age of oil lost.  Short waves (with the exception of those 10-foot  long
waves which excite the boom's natural frequency) impact the boom, and the
boom responds like a breakwater, creating a much calmer area within the
quiet region of the boom and behind it.  In wave periods longer than 2
seconds, the boom will tend to follow the water surface like a boat, be-
ing limited by the freedom of motion of the connections when the direction
of wave propagation is not normal to the boom.  This boom is best suited
for permanent service in waters where waves are generally less than 1 foot
high.

     The high-current boom is designed to allow current-borne debris to
slide past underneath.  Nevertheless, we expect that buoyant debris will
accumulate in front of the boom.  This debris must be cleared either by
manual removal or by opening the boom to allow debris to pass on.   The
sturdy boom design plus spring-like cable moorings should avoid damage
from debris collisions with the boom.

OIL RECOVERY TECHNIQUES

     Oil transported by fast-moving waters and diverted shoreward by the
high-current boom accumulates rapidly.  Means must be provided in a
typical field installation to rapidly recover oil as it accumulates.

     The high-current boom is compatible with virtually any type of skim-
mer that will fit within it.  For light oils it is appropriate to use a
floating suction skimmer.  There are a variety of floating suction skimmers
that can be used with this boom.  Additionally, Shell has developed one
for other purposes (1) that is also suitable for this application.

     Adsorbent belts - because of the nature of oil adhesion - work better
on more viscous oils such as Bunker "C".  An example is the mop-like
adsorbent rope belt shown in Figure 8.  The rope belt is operated in a
closed-loop fashion inside the entire length of boom and oil is wrung
from the belt and recovered at the shore.

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•
                              FIGURE 1 - TESTING IN WAVES WITH NO. 2 FUEL OIL AT  OHMSETT

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FIGURE 2 - TESTING IN WAVES WITH NO. 2 FUEL OIL AT OHMSETT

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FIGURE 3 - TEN MODULES  JOINED TO MAKE ONE RIGID SECTION OF BOOM
           (SHOWN FLOATING IN A RESTING POSITION - NO CURRENT
           AND NO WAVES)

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FIGURE 4 - FOUR-FOOT-WIDE HIGH CURRENT BOOM TEST SECTION

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FORWARD
                                                                                           AFT

                                             —4-1/2'f*—
                                                                          dx_^   ^*_^
                                                                             o   o
                                                                          o   o
                                                                        0.0.0
(50% Open)
                                           2" diam.
                   FIGURE 5  -  PROFILE OF THE RIGID, PERFORATED  PLATE  BOOM

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NOTE:  Figure 6 on pages 12-15.
   o
   :*:
    o
   U
   O

   OJ
   ro
   O
   5-
   O
15           30          45
 Diversion Angle,  0, Deg.
                                                           60
      FIGURE 7 - PREDICTED PERFORMANCE OF HIGH-CURRENT BOOM WITH LESS
                 THAN 10% OIL LOSS.  BASED ON FULL SCALE TEST RESULTS
                 (p  = 0.89) AND FROUDE NUMBER SCALING FOR OTHER p  'S
                                  11

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                                               LE.MSTH  qlER_A,V.l.
12

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14

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                 _ PET/ML-
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                                      *         .
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                                                                    MIL R 400 SIM 10 MLBC MR*. CQ OR EAOM.
                                                                    At>«ESWE IN ACCOROAM
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                                                                    FRAMES- OWT OM OME SIDE Of EMO
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                        BEMD UP 30° PITCH _ ;_
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     FIGURE 6B - EPA HIGH-CURRENT  BOOM  - BOTTOM PIATE AND  DETAILS
                                              15

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NOTE:  Figure 7 on page 11.
                           -Tail Pulley
    Mooring
     Lines
     Piling
     Typ-
Perforated Plate Boom
  (7 Modules Shown)


   Adsorbent Rope Belt
                            Wringer/Drive

                     Adsorbent Rope Belt Skimmer
               FIGURE 8  -  EXAMPLE  OF MEANS TO RECOVER OIL
                                   16

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APPLICATIONS

     Diversionary Boom.  This most obvious application for the high-current
boom is downstream from oil loading/unloading docks.  Figure 9 shows a typical
permanent installation of this type.  The design of the boom installation near
a shoreline will differ depending on the shoreline topography and other consid-
erations.  It is essential, however, that skimmers be available to rapidly
recover oil as it is diverted shoreward.  The mooring system design should
include a power winch to allow easy opening of the boom to free debris accumu-
lations.  The design should also include "weak links" in the moorings to allow
the boom to break free and string downstream in the event of excessive flood
water currents or collisions with large floating objects.

     Boom modules are also designed for truck transport to a spill location
and the joining process is quick and simple, permitting their use on an ad hoc
basis in a spill emergency.

     Emergency Self-Propelled Skimmer.  Another useful application of the high-
current boom design is to make a skimmer from an ordinary work vessel or fish-
ing vessel in an emergency.  A configureation of this type is sketched in
Figure 10.  Of course adaptive elements are required in attaching the boom to
the vessel of convenience.  Truck transport of boom modules for this purpose
is warranted by the predicted performance.

     Inshore Skimmer.  If supported by a vessel having a "U" shaped bow, or by
a very small and shallow draft barge, module(s) can be used as a sweep skim-
ming device for inshore waters.  Two possible configurations are shown in
Figures lla and lib.
                                      17

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                     Flow
          Bank
                 Pi1i ng
                                         Mooring Line
                                High-Current Boom
      FIGURE 9  -  PLAN  VIEW OF HIGH-CURRENT BOOM IN
                 DIVERSIONARY CONFIGURATION
         Vess
        Pump
2 High-Current
 Boom Modules
                                           Skimmer
                                          Transition Element
                                Storage
FIGURE 10 - EMERGENCY SELF-PROPELLED SKIMMER USING RIGID,
            PERFORATED-PLATE BOOM MODULES
                                18

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                 Flow
  Bow
Stern
                                                                                Flow
                          Rigid Boom Module
                                 Floating Suction
                                    Skimmer
                                   Skimming
                                    Vessel
                                                             Bow
              O)0

 a)  Monohull Vessel With Permanent Storage
                                                     Boom
                                                    Module
                                                          Stern
                                                                                   Deck
                                                                                   Tie (Typ.)
                                                                                    Skimmer

                                                                                    Pontoon
                                                                                     (Typ.)
                                                            Outbd. motor
                                                                              Deck
                                                                     To Towable Bag

                                         b)  Catamaran Vessel  With Towable Bag Storage


FIGURE 11 - TWO PERMANENT SKIMMER CONFIGURATIONS USING RIGID BOOM MODULES

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                        V.   DISCUSSION OF THE -PROBLEM

THE PROBLEM

     Historically and presently the most effective way of controlling the
movement of oil spilled on water is to use floating oil barriers.   At pre-
sent there are over 80 different commercailly available oil spill barriers,
or booms.  In recent years significant improvements have been made in the
basic oil boom design:  They include increasing the boom freeboard to mini-
mize oil splashover in waves, enhancing boom flexibility to allow wave com-
pliance, improving boom strength and stability in currents and making design
changes to facilitate handling, deployment, cleaning and storing.

     In spite of these improvements in design,  however, a fundamental problem
remains in controlling oil with booms in high currents and in steep waves.
This report considers the problem of oil spill control on fast-moving waters
as found in rivers and tidal estuaries.  The problem of oil booms in waves is
equally challenging, but one must understand the separate effects of currents
and waves in order to understand their complex interaction.

     Analysis of possible clean-up techniques applicable to an oil spill on
fast moving waters makes it clear that the response time is critical.  Re-
sponse time is measured from the time a spill is reported to the time clean-
up equipment is mobilized and working.  If a spill occurs on a river where
the current is 3 knots (See English-Metric Conversion Table, Appendix G) , for
instance, the oil lens centroid would be approximately 1.7 miles downstream
in 30 minutes, neglecting the effects of wind and spreading.  Use of oil
booms for this situation would be limited to the following cases:

     (1)  Durable permanently-deployed floating booms.

     (2)  Stored booms ready for immediate deployment at a location down-
          stream within response constraints.

     (3)  Completely portable boom systems capable of being rapidly trans-
          ported and deployed at any location.

     In most cases it is important to immediately remove oil temporarily con-
tained or diverted by a boom, because oil can be lost by droplet  formation
[escaping at current velocities as low as 0.7 knots  (2)].

     A containment boom is normally fixed at each end and  the  elongated bar-
rier is allowed to drape in a U-shaped catenary because of current drag
forces.   Such a boom configuration is shown in Figure 12a.  Oil drifting
toward a boom, if retained, will thicken locally in  front  of the  boom (set-
up), making oil removal feasible.  Shell tests  (2) have shown  that booms of

                                      20

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                   (a)  Plan view of containment boom
       Flotatio
Weight
       Section A-A
                     Skirt
Deformed Shape
   Typical Boom Profile
        (Enlarged)

                   fb)  Plan view of diversionary boom

        FIGURE 12  - CONTAINMENT AND DIVERSION IN RIVER CURRENTS
                                 21

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usual dimensions  can  allow oil to escape at velocities as  low  as  0.7 knots,
although under  certain conditions oil containment at velocites up to 1.5
knots has been  achieved.

     A large number of experiments (3,4)  directed toward  understanding the
various mechanisms of  oil failure under a containment boom have  generally
revealed that containment is feasible with shallow to moderate draft conven-
tional booms in currents up to 1.5 knots.

     One generally accepted analysis (3)  of "drawdown" oil losses under a con-
tainment boom indicates that in a 2-1/2 knot current, skirt  drafts  of 4 to 10
feet are needed for oils having specific gravities of 0.85 to 0.95.  Since
drag forces increase as the square of the velocity and linearly  with increased
draft, the structural  strength and stability of a boom in fast-moving waters
is also of major concern.  We conclude that high-current  containment using
deep-draft booms is not a viable approach to the problem.

     A diversionary boom is moored at an acute angle  to the  river flow and
shunts oil from the high velocity flow region in the  middle  to the slower
region near the bank (Figure 12b).  The diversionary  boom shape  has been found
in practice to keep oil from escaping downstream in higher currents than the
containment boom shape.  A diversionary boom, however, is difficult to moor
such that every segment of the boom makes the same acute  angle with the flow
vector (to afford maximum oil retention).  The natural tendency  of the boom is
to deform under flow forces as indicated by the dashed line  in Figure lOb.
When any portion of the boom is nearly normal to the  flow, containment boom
losses can occur.  Thus diversion, usually with shallower conventional booms,
offers more promise than containment.  But even diversion can be inadequate in
moderately high currents.  A more complete discussion of  diversion and contain-
ment is contained in the next part of Section V.

     Many of our rivers and tidal estuaries have currents in excess of two
knots.  Since mere design changes of the conventional boom do not hold prospect
for fast-moving waters, a radically different concept is  appropriate.  Our
approach is to improve upon the conventional boom profile by adding a baffle
immediately upstream of a boom to slow down the surface flow. Based on test
results such a baffle/boom combination - an unconventional boom  profile -
offers effective oil control in higher currents in both containment and diver-
sion applications.

LIMITATIONS OF CONVENTIONAL BOOMS

     A conventional boom is shown in Figure 13, as it was used in an oil spill.
The components of a typical boom are sketched in Section A-A of  Figure 12.
Although there are differences in the way they are moored, i.e., bottom-
tensioned, top-tensioned, or skirt-tensioned, the loss of oil in each case  is
generally determined by the effective boom draft when current forces are
acting (and not the still-water draft).  The following is a  discussion of the
mechanisms of oil loss for booms used in both containment and diversion.  The
normally reported profile of oil accumulated against  a barrier is  that for  a
large contained volume as shown in Figure 14a.  Possible failure mechanisms
are entrainment near the headwave (shown) and drawdown near  the barrier.
Our specific interest  is in small contained volumes because  in high  currents -
the major concern of this program - rapid, simultaneous oil  recovery is
essential.

                                       22

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             FIGURE 13 - CONVENTIONAL BOOM CONTAINING SPILLED OIL

     Figure 12a shows a typical oil boom placed across a river in the contain-
ment configuration.  Provided that the set-up oil volume is small (slick
length < 5 times the boom draft), oil loss under a boom is skirt draft sensi-
tive and can be described by the densimetric Froude number:

                                Fd = V/(gAh) /2                             (1)

     where

                    V = Free-stream velocity
                    g = Acceleration of gravity
                    A = Fractional density difference,

                        (pw - P0)/Pw

                        (p  = water density, p  = oil density)
                    h = Barrier draft

     Recent Shell tests indicate that the inception of "near-boom" oil loss,
as shown in Figure 14b, occurs when

                                    Fd = 1                                 (2)

Previously (2) such losses were thought to be independent of skirt draft.

     A physical explanation for this failure mode follows:  If the contained
oil volume is small, it will accumulate in the wedge of water in front of the

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    FAR BOOM REGION
NEAR - BOOM ^
                                               REGION
              HEADWAVE
FLOW
(a)  LARGE  VOLUME  OIL  SET-UP
         NEAR-BOOM  REGION  < 5h
FLOW
(b)  SMALL  VOLUME OIL SET-UP
     FIGURE 14 - OIL SET-UP IN FRONT OF A BARRIER  IN A
              TWO DIMENSIONAL CURRENT FIELD
                         24

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boom (see Figure 14b) .  In this way the set-up lens is protected from the high-
velocity streamlines associated with water flow under the boom.   There is
sufficient suction when F, = 1, however, to allow oil to draw down under a
boom.  Figure 15 contains curves for the minimum boom draft requirement for
small-volume containment as a function of free-stream current and oil specific
gravity using a 1.0 Froude number.

     A second oil loss mechanism associated with droplet formation at the head-
wave is called "entrainment"*.  This loss generally occurs in containment with
larger contained oil volumes at about 1 knot.  As discussed below, the entrain-
ment mechanism is the probable cause of diversionary losses at moderate
currents.  Wicks (2) suggested that droplets will form when the  Weber number
based on oil droplet diameter exceeds 22, i.e.,
22
                                     p V2  d
                             <»•>« - -Vi
                                        ow6
     where

                       V   = Critical velocity

                       d   = Maximum oil droplet diameter

                       0   = Oil/water interfacial tension
                        ow
and other symbols are described previously-  Wicks (2) further suggests  that
the maximum droplet diameter is given by
     Since very few droplets of maximum size are likely to occur,  the question
is:  "What is the most probable average droplet diameter associated with the
inception of measurable losses?"

     Both tests and field experience have suggested that a velocity of 1 knot
is large enough to cause diesel oil loss by entrainment.  The sudden failure
which occurs with large contained volumes at currents in excess of 1 knot is
illustrated by data in Figure 16 from offshore oil boom tests by the U. S.
Coast Guard. (5)  The test oil in this case was soybean oil.

     One can estimate the effective droplet diameter consistent with Equations
(3) and (4) by assuming for light oils such as diesel fuel oil in fresh water:
* In this duscussion "drawdown" implies oil losses are sensitive to skirt
  draft and thus dependent on the densimetric Froude number.  "Entrainment"
  implies no skirt draft dependence and is governed by the Weber number.  Both
  types of losses look like droplet failure.
                                       25

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-------
                        Vcr =  1 knot =1.69  fps

                        a   =30  dyne/cm =  .0021 Ib/ft
                         ow        J

                        PQ  =  0.85 g/cc  = 53.07 Ib/ft3

                        p   =  1.0 g/cc = 62.43 Ib/ft3
                         g    =  32.2  ft/sec3

     Using Equation  (3)
                            22  a    g
                               ow 6
                     deff  =  p—V2	 =  °'0083  ft or °-1 lnch
                            w  cr
     And  from Equation (4)
                                 d  =  0.565  inch
                                 o
     Thus


                                  -~- = 0.18                               (5)
                                    o

     If we  further  assume  that Equation  (5) is approximately true for all oils,
 then the conditions for  entrainment failure are quantifiable.

     A diversion boom placed  to  divert oil to shore in a river was shown pre-
 viously in  Figure 12b.   Because  test results suggest that deep-draft booms  do
 not divert  oil better than shallower ones, we suspect entrainment to be the
 governing failure mechanism in diversion.

     The only required modification to Equations  (3) - (5) is to substitute
 the normal  (to the  boom) component of  the free-stream velocity for the free-
 stream velocity.  Then,  for diversion

                                       22 a   g
                                                                            f,.
                                                                            (6)
                                cr ~ p  d  „
                                    *w  eff
and, as before
     The predictions of Equations  (6) and  (7) are plotted  in Figure 17  as  a
function of diversionary angle.  For a No. 2 Fuel Oil spill, for  instance, a
conventional boom - if stable and  carefully moored - will  successfully  divert
oil at a diversionary angle of 60° in currents up to 1.5 knots.

                                      27

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O)
              Width in Fet
               >K-450
      1200
1300        1400       1500       1600

  Pacific  Standard Time - Hours
           FIGURE  16 - HISTOGRAM OF OIL LOSS FROM COAST
                      GUARD BOOM TOW TESTS (FROM REFERENCE 11)
                                28

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   2.0
 VI
 4->
 o
 o

 O)
>



 o
•r—
4->

 £
O
   1.5
1.0
    .5
                  15
                           30           45           60

                          Diversion Angle,  9,  Degrees
75
              FIGURE  17 - CRITICAL  VELOCITY FOR OIL LOSS IN DIVERSION
                                     29

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PREVIOUS SHELL INVESTIGATIONS

     Late in 1969 Shell found means for containing oil at a current velocity
in excess of that found for conventional booms (Figure 18).   The technique
used was to alter the near-boom region (compare with Figure 14b) to prevent
premature oil drawdown when small oil quantities are set up.  The boom section
tested in 1969 could be considered a special case of a general means for
creating a quiescent pond by diffusing the fluid flow.  This was accomplished
by placing baffles  (the vertical net and the horizontal lower perforated mem-
brane in Figure 18) in front of a conventional barrier.  The downstream length-
to-draft ratio of the profile tested in our laboratory current tank is 4.5,
meaning that the upstream face is close to the streamline separation point for
a conventional barrier in potential flow-  We found that:

     1.  When small quantities of oil were placed between the upstream and
         downstream floats, the critical velocity was increased from 0.7
         knots for a conventional barrier to 1.4 knots for the test profile—
         a two-fold increase  in containment velocity.

     2.  When oil was placed upstream of the boom profile the oil entered
         the upstream net.  But upon passing through the net, the oil lens
         broke into many small droplets.  The entrained droplets were then
         lost through the bottom membrane at velocities between 0.7 and
         1.4 knots.
                 Float
   (Possibly  Pervious)
           FLOW
            Screen
                         Bottom Membrane —^
                          (With Holes)
              FIGURE 18 - FIRST HIGH-CURRENT BOOM MODEL BY SHELL

     The conclusion drawn from the exploratory tests is that although the un-
conventional profile had the capability of doubling the containment capacity
of a conventional boom, an alternative to the forward net baffle must be found
to overcome the oil entrainment problem.

     The basic principle of artificially creating a quiescent pond to allow
oil to set up in a relatively thick lens is generally accepted today as a
valid technique.
                                       30

-------
     Recognizing that the fundamental process involved in creating an artifi-
cial quiescent pond is flow diffusion and that the forward oil entry region
must be a relatively open configuration, a suitable alternative was devised.
In further tests of the flow diffusion principle a forward baffle was formed
using a bundle of short parallel tubes (with center-lines parallel to the flow
vector) and a lower submerged baffle to replace the previous net and by using
an open-bottomed "Coke box" grid to replace the lower porous membrane.  The
revised test section, shown in Figure 19, was found to eliminate oil entrain-
ment problems observed in tests of the earlier model using a net.

     As seen in Figure 19 the improved boom profile has a more lengthy upstream
to downstream "boom profile" dimension than a conventional boom, somewhat like
a skimmer.  The flow diffusion principle, of course, is also applicable to
skimmer configurations.  Since it would be quite difficult to develop a flexi-
ble elongate boom with such a complicated cross-section, in earlier development
programs we decided to change the original boom concept into a flow-diffusing
baffle system for a sweep-type oil skimmer.  Early in 1972 a prototype inshore
sweep skimming system  incorporating flow diffusing baffles was designed and
fabricated (1).  Investigations revealed that flow diffusing baffles could be
thought of as flow energy absorbing baffles, the idea being to extract the
maximum flow energy from the relative water velocity while at the same time
endeavoring to minimize oil entrainment caused by excessive turbulence.  The
baffle systems used in developing the skimmer were incorporated directly,
without attempting to optimize the configuration.

     This report describes using flow-diffusing techniques to design a high-
current boom.-

INVESTIGATIONS OF OTHERS

     Early in 1970 the Garrett Corporation (6) conducted tests on a "quiescent
pond" baffle arrangement for use in a proposed skimmer arrangement for use in
the API-sponsored Sea Dragon offshore skimming system.  The baffle system that
Garrett tested as a skimmer can be equally considered as a two-dimensional
unconventional boom profile.  Figure 20 shows one configuration applicable to
a boom design that they evaluated.  It includes a forward spillway and bottom
louvers.  Garrett model tests proved that the combined forward and submerged
lower baffle systems of their design were essential to the effectiveness of
the quiescent pond.  They did not, however, have an effective forward baffle
arrangement for minimizing bow turbulence effects in waves.

     Early in 1971, Atlantic Research Corporation (3) found that a bottomless
double boom arrangement had greater velocity capability for oil retention than
that of a conventional boom.  Their investigations revealed that the profile
shown in Figure 21 had a 25% increase in containment capability over that of a
conventional barrier.  Important test results are that the forward barrier
must be hydrodynamically shaped to reduce entrainment effects but that a flat-
plate aft barrier is adequate.

     In late 1971, Ocean Systems, Inc. (7) tested the unconventional boom con-
figuration shown in Figure 22.  The "dynamic keel" 1/3-scale version, having
a width of 2-1/3 feet and a draft of 10 inches, had an oil loss rate of  9%  at
0.9 fps (based on the volume of oil applied) and 52.5% at 1.5 fps.  This
                                       31

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                               .Side Fins
           Rectangular  Baffles
A
      Fwd Tube Bundle
Oil Accumulation
     Area
                                 Plan View
   Flow
                                                    X     X
                                Section  A-A
                    FIGURE 19 -  REVISED BAFFLE  CONCEPT
                                    32

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              Floating Weir
Flow
                        Forward Section
                        (Spillway)
                                                  Louvered Bottom
      FIGURE 20 - A PRELIMINARY CONFIGURATION FOR PROJECT SEA DRAGON
                  MODEL TESTED BY THE GARRETT CORPORATION
                                  7.0'
           Foward
           Barrier
  Flow
                FIGURE 21 - DOUBLE-BOOM CONCEPT TESTED BY
                            ATLANTIC RESEARCH CORPORATION
                                33

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                               77'
                      Forward Slotted Weir
Flow
    FIGURE 22 - OCEAN SYSTEMS DYNAMIC KEEL CONCEPT
                        Inclined Plane
    Flow
                                                        Gate
     FIGURE 23  - JBF FIX^D, INCLINED-PLANE CONCEPT
                              34

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velocity produces smaller densimetric Froude numbers than that for a conven-
tional boom.  Their means of scaling these results to larger versions is
unclear.

     The JBF Scientific Corporation (8) developed the SHOC, an inverted,
inclined-plane skimmer  (See Figure 23), for the EPA.  Their concept, although
reasonably effective when used as a skimmer at moderate currents, would pose
problems when used as an unconventional boom at high velocities.

     During the  test program reported here, the Pace Company (Toronto, Canada)
developed and placed on the market a flexible double boom configuration for
use in fast-moving waters.  The boom profile is sketched in Figure 24.  Oil
and water enter  the forward net section below the forward float; then oil is
accumulated and  (some) water passes through the water-permeable aft skirt
section.  Sufficient test data are not presently available on this boom.

     Finally, a  number of different high current control concepts (9,10), some
applicable to both booms and skimmers, are presently in various stages of
development.  This research, directed toward controlling oil in 4 to 10-knot
currents, is sponsored by the U.S. Coast Guard and the U.S. Environmental
Protection Agency.
                                       35

-------
Some oil
accumulates
here and  moves
along float
in diversion
48"
                                                          DOWNSTREAM-FLOAT
                                Some oil
                            accumulates here
Flow of Water
('D1 Between 20-28 inches
     depending on
     current)
                 Water  Porous
                 Membrane
               FIGURE 24 -  PACE FLEXIBLE DOUBLE BOOM CONCEPT
                                   36

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                          VI.  INITIAL BAFFLE STUDIES
INTRODUCTION

     The objective of the initial baffle studies which Shell conducted under
this contract with the EPA was to determine what types of baffles might be
useful for diffusing flow when incorporated in a high-current boom design.
The approach used was to examine and improve two-dimensional models of candi-
date baffles by iterative tests in a closed-loop current tank using PVC beads
to simulate oil.  The most successful candidate was subjected to further 2-D
model tests and then tested and modified in a wave/tow tank using oil.   A
series of 10 full-scale boom modules were built and tested further under
three-dimensional conditions and finally demonstrated at OHMSETT.

     One clear constraint is that a flow diffusing baffle must perform effec-
tively at various diversionary boom angles as well as normal to the flow.
Also baffle candidates should have a relatively shallow draft in order to
improve on conventional containment boom capabilities in fast-moving waters.
Other considerations include lack of debris-fouling problems, wave conformance,
and simplicity of design (hence economy).

     Two different baffle configurations were chosen for initial experimenta-
tion.  They are the inclined, perforated-plate, and the stub-tube array
baffles shown in Figure 25.  Previous Shell investigations indicate that
baffle candidates should have relatively large openings, (as contrasted with
small ones like small mesh nets and screens).  Screens cause prolific small-
diameter droplets to form as oil passes through.  Droplets sweep under the
barrier before they can recoalesce, causing substantial oil losses.  Both of
the candidates have large open-area-to-total-area percentages as indicated in
the figure.  Also, both candidates accommodate moderate changes in diversionary
flow angle without significantly changing the flow-baffling capability.  One
form of stub-tube array baffle is used in the (API) Open Seas Skimmer
design (1), but that baffle is designed specifically for offshore waves and
is not necessarily optimal for high currents.  In this program we have
attempted to optimize the stub-tube baffle primarily for high currents  (but
in the presence of river-type waves).  The perforated plate baffle, on the
other hand, is likely simpler to construct than the stub-tube one and it
should accommodate debris better.

     Our experimental approach was to first study the behavior of a given
baffle in water flow alone.  By not using oil, underwater observations were not
clouded and tests could be conducted more quickly and economically.  The  Shell
Current Tank, shown in Figure 26, was used for this series of experiments.
During tests a reference velocity (upstream from the test section) was  contin-
uously recorded using a Marine Advisor's 5-inch (See English-Metric Conversion
Table, Appendix G) Ducted Current Meter.  Local velocity readings upstream  and
downstream of the baffle array were made using a small A. Ott Kempten Model  C-l

                                      37

-------
0 0 ° 0
0 . O _
o o °
O O
0 O
v 	
o
0
o

o
A, 	
v 	



\
LENGTH

SEGMENT

OF BOOM
                     PLAN
  WATER FLOW
                     PROFILE
(a) STUB TUBE ARRAY BOOM
               ooooooooo
                ooooooooo
               ooooooooo
                ooooooooo
                                 v-
                                           PLAN
  WATER FLOW
(b)  PERFORATED  PLATE BOOM
                                          PROFILE
          FIGURE 25 - INITIAL BAFFLE CANDIDATES FOR
                    THE SHELL STUDY
                           38

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FIGURE 26 -- SHELL CURRENT TANK
            (GASMER LOCATION)
                    39

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non-ducted propeller-type meter.  Revolutions of the propeller per thirty
second interval were electromagnetically counted and the counts were converted
by a linear equation to the velocity in feet per second.  Flow directions were
determined using streamers.  A qualitative measure of the oil containment
capacity of a baffle-boom profile was obtained by placing sawdust or 0,9
specific gravity PVC beads in the water in front of the device and determining
the approximate quantity accumulated by the device.  Of course, the beads do
not simulate the surface properties and viscosity of spilled oils, but they
are rapid and efficient for qualitative testing and do afford a rough measure
of the comparative effect of oil specific gravity on the oil retention capacity
of a baffle-boom combination.  Numerous photographs were taken to document the
observations made during the experimental program.

SUMMARY

     The perforated plate boom profile shown in Figure 27 has been found to be
better than the stub-tube boom in Figure 28.  The choice was based primarily
on the capacity of the two-dimensional boom profiles to retain simulated oil
(0.9 sp. gr. PVC beads).  The full scale inclined perforated-plate profile
collected between 90 and 100% of the beads encountered at 2.4 knots.  The
stub-tube profile tested at a geometric scale of 78% of full scale, retained
90 to 100% of the beads at a velocity of 1.75 knots.  Using an optimistic
scaling law based on the (single fluid) Froude number, the model tests on the
stub-tube profile predict 90 to 100% simulated oil retention at a prototype
velocity of 1.97 knots.  Thus the inclined plate profile shows the same
retention capacity at a free-stream velocity 23% greater than for the stub-
tube profile.

     Secondary considerations involved in selecting the inclined plate profile
(Figure 27) were the:

     1.  estimated effect of debris on the profile,

     2.  ability to design a buoyant upstream structure in which flotation
         does not reduce the effectiveness pf the boom,

     3.  fabrication complexity of the profile, and

     4.  projected structural adequacy and dynamic stability of the final
         boom arrangement.

     The design of Figure 27 was later altered based on further tow testing
with oil.

STUB-TUBE BAFFLE EXPERIMENTS (Model Scale)

     Various arrays of stub tubes were placed in the test section of the
current tank to explore their capacity to cause a velocity drop while minimiz-
ing turbulence and allowing simulated contaminents  (initially sawdust and
later PVC beads) to pass through on the water's surface.  Figure 29 shows the
general test set-up used in these experiments.  Details of experimental inter-
actions are contained in Appendix A.
                                       40

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     To explore the effects of scale on the performance of these stub-tube
arrays, several sizes of tubes and spacings were investigated.  We assumed
that flow effects would basically scale using the Froude number.  This number
is normally utilized in cases of surface-piercing solid objects in a fluid
flow field.  Consequently, in Froude scaling, lengths scale geometrically and
velocities scale as the square root of the geometric scale.  "Full scale" was
arbitrarily selected as a tube diameter of 1.68 inches.

     In the first twelve experimental conditions, called SM (for stub-tube
model) -1 through SM-12, we investigated various tube diameters, orientations,
and array spacings.  With arrays having uniform longitudial and transverse
spacings, the pressure drop caused by the baffle was concentrated near the
first three rows.  Turbulence was generally intense there and quite calm in
subsequent downstream rows.  We increased the spacing of the first two rows to
reduce the local turbulence, but this was to no avail.  Perhaps one could
experiment further with altering spacings to a more optimum condition, but we
observed that even a single tube upstream of an array magnified the turbulence
at the front of that array.  Then we decided to try means to reduce the venti-
lation phenomenum  (air entrained in the water just behind a surface-piercing
tube).  Plastic streamers were slipped on an individual tube to make it look
like a surface-piercing symmetrical "wing" shape in order to reduce vortex
formations.  This had a beneficial effect on ventilation.  Also horizontal
fins  (like that used on the submerged leg of an outboard motor) were added.
We observed that with a single tube, ventilation was reduced.  The problem is
that the vertical component of turbulence generated is unacceptably high, and
neither the streamer nor the fin reduced it sufficiently to avoid oil loss.

     While experimenting with a row of tubes using fins, we noticed that flow
downdraft was less when the row was placed at an upstream or a downstream
angle, rather than vertical.  Accordingly, we explored both upstream and down-
stream angular changes to find a condition that produced less severe turbu-
lence.  In tests SM-8 through SM-11 we experimented with a "V" shape (in
profile) with the first row of tubes slanting downstream and below and the
second row slanting upstream and below such that the lower ends of the tubes
in both rows formed the base of the "V".  Having found a suitable stub-tube
arrangement, we experimented with three different tube diameters, all geomet-
rically similar.

     Experiments SM-12 through SM-31 use the same baffle arrangement as was
used in SM-8:  By trial and error we chose barrier draft and distance down-
stream of the array, using retention of PVC beads as a basis for selection.
The maximum model velocity for these tests was 3 fps which scales to 4.2 fps
(2.5 knots) if 3.31-inch tubes were used as prototype size.  In the last
experiment, SM-31, a horizontal board was placed at mid-draft between the  legs
of the first two rows (forming the "V").  This improvement allowed a bead
retention of 93 percent at 3 fps.

     At this point the configuration of the stub-tube baffle boom was consi-
dered satisfactory, and the design was frozen.  Following similar development
of the perforated plate baffle concept, the two concepts were  compared.
                                      41

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NJ
                                IMPERVIOUS  BOARDS TO PREVENT VENTILATION
                                  L
            FLOW
                                   18.8% OPEN AREA (TYP)
                            PROFILE
                                 SCALE  1"=16"
                                                                             OPEN 
-------
FLOW
 SCALE  \n*Q"
                              •3 FINS-SEE
                               DETAfL "A"
OJ§"
                                                          FLOW
                     PROFILE
                                                                                   0.38"
                                                                     DETAH.  A
                                                                       (NTS.)
                       FIGURE 28 -  TENTATIVE OPTIMUM STUB TUBE BAFFLE BOOM ARRANGEMENT
                                   BASED ON ONE-HALF SCALE MODEL TESTS

-------
                /TANK WALL
FLOW,
                    TUBE ARRAY
                          PIPE)
               •  •  •
                 •   •
               •  •  •
                •  •
               •  •  •
         PLYWOOD
         SIDE BOARD (TYP)
                             CM
                             N-
POSTS FROM ABOVE
TO RESTRAIN SIDE BOARDS
   TANK WALL
                CURRENT TANK WINDOW
                       PLAN  VIEW
^

+x
1 v"
r
»••




,f
PLEXIGLAS WINDOW
f f f T ? /

1 •

•*^




-/







f 10"
I 18
JL DRAFT
                   SECTION A-A
        FIGURE 29 - TEST SETUP OF STUB TUBE ARRAY IN CURRENT
              TANK  (SIDE BOARDS PREVENT 3D EFFECTS)
                              44

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PERFORATED-PLATE BAFFLE EXPERIMENTS

     A second candidate design concept for the high-current boom is the
inclined, perforated-plate baffle shown previously in Figure 27.  The initial
choice of baffle geometry for the current tank experiments was a 2-inch-diameter
hole array on a flat plate such that a 46 percent open-area-to-total-area ratio
is obtained.  Using two identical plates and sliding one with respect to the
other, open area ratios between 18.8 and 46.0 percent were obtained.  These
dimensions are considered "full scale" and not "model" as was the case for the
stub-tube baffles.  Because of the uncertainty of scaling laws for the inclined
plate, we decided to test a full scale device.  As before, local current
measurements were made to determine velocity reduction and PVC beads were used
to find the bead retention.  Details of the trial and error experimentation
are included in Appendix B.

     Tests IPM  (meaning "inclined plate model") -1 through IPM-13 were con-
ducted using a single perforated plate, sloping below and downstream to
achieve a planing configuration.  The open-area ratio, plate inclination and
downstream barrier draft and location were varied systematically.  None of the
changes produced an acceptable bead retention at a reference velocity of
3.75 fps, so an additional perforated plate was added to the design.

     Then various combinations of plate orientations were tried, including
both upstream and downstream slope angles of both plates.  An anti-ventilation
board was placed against the upstream plate at the waterline in some of the
runs.  The board had a positive effect in reducing ventilation, but it unfor-
tunately increased bead losses.  A Coke-case baffle (Coke case with the bottom
out) was added to the design in an attempt to reduce turbulence  (and bead
losses) but this did not work.  Finally, a configuration with two planing
parallel plates was found to be promising.  But even then fluid downflow
between the two plates caused beads to pull under.  The downflow problem was
solved by placing three equidistant (solid) horizontal plates between the
parallel perforated plates.  This configuration, regarded as the best of the
33 tests, is shown in Figure 27.  With both plates 18.8 percent open and with
an 11-inch barrier downstream, approximately 80 percent of the beads were
retained at 4.8 fps (2.9 knots, Experiment IPM-28).  This compares with 93 per-
cent bead retention at a (full scale equivalent) velocity of 4.2 fps (2.5
knots) for the sub-tube baffle (Experiment SM-31).

     Since the perforated plate baffle worked well at a velocity of 0.6 fps
(0.4 knot)  higher than the sub-tube baffle, tow tank testing was conducted
only with the perforated-plate baffle.

PRELIMINARY TOW TESTS - PERFORATED-PLATE BOOM CONCEPT

     After the perforated-plate boom concept was chosen over the stub-tube
boom,the experimental work changed from current tank tests without oil to wave/
tow tank tests with oil.  In the initial tow tests the perforated-plate boom
model used in the current tank was fitted with outrigger flotation for towing.
Figure 30 is a photograph of the boom profile, complete with outrigger flota-
tion.  The outriggers, of course, are only test fixtures.
                                       45

-------
     The initial objective of conducting tow tests on the previously current-
tank-tested model was to find out if the design works as well with test oils
as it did with the oil-simulating PVC beads.  A few preliminary tow tests were
run to examine this.  We found in a qualitative way that the profile did not
work as well with oil as it did with the beads.  Because of this difference in
behavior, we felt that further trial-and-error configuration improvement tests
were warranted.

     The first nine tow runs in this period used the configuration shown in
Figure 25.  The general test procedures are itemized in Appendix C of this
report.  The test oil is a light distillate resembling Number 2 Fuel Oil.  Two
types of tests were run:   (a) a "constant flow rate" test in which oil is
sprayed on the water in front of the device during a tow run, and (b) a
"constant volume" test in which oil was placed inside the boom initially and
then the boom is towed without applying additional oil.

     Summarized test results are shown in Table 1.  We found that in the con-
stant volume tests the percentage of oil retained in the sump area of the boom
was about 90 percent.  For the constant flow rate test, however, an average oil
retention of about 65 percent was found.  This means that a greater percentage
of oil is lost under the device when the oil on the water's surface passes
through the perforated plate toward the sump area.  Apparently the oil lost
drains down the front face of the perforated plate rather than passing through
it.

     A better boom, we think, is one that has the same percentage oil loss in
both types of tests.  Tests 10 and subsequent were conducted to find such a
configuration.  After trying various open-area ratios once again (this time
with oil) , various configurations of parallel but spaced-apart horizontal
plate stacks, located between and behind the perforated plates, were tested.
The plates were used to reduce flow downdraft and force oil horizontally
through the perforated plate baffles.

     Finally, in Tests 34 and 35 the most satisfactory configuration emerged.
As shown in Figure 31. Configuration G, the design includes no second plate.
Instead, a lower horizontal (and perforated) plate is added just upstream of
the barrier, connecting the lower part of the forward perforated plate to that
of the barrier.  This submerged, perforated plate limits the water flow from
the boom; consequently, a more open 46 percent plate could be used.  Approxi-
mately 85 percent of the oil applied was retained by this boom at a tow
velocity of 2.5 knots.  Figure 32 is a sketch of the preferred perforated-
plate boom configuration before flotation was added.
                                       46

-------
   (A)   Outrigger flotation attached to the
        Inclined  plate  boom for tow tests.
   (B)   Photograph showing the test fixture
        attached to the front of the boom.
 FIGURE 30 - PHOTOGRAPHS OF TOW 2-D TEST MODEL
(FULL SCALE) (  SEE ALSO FIGURE C-l, APPENDIX C)


-------
PERFORATED PLATE TOW TESTS




          TABLE 1
Run No.
1
2a)
3a)
4
5
6a)
7a)
8
9
ioa>
lla)
12
13
14a>
15a>
!6a)
17
18
19
20
21
22
23
24
25
26
27i)
281'
29i)
301'
3115
32i)
33i)
34"
35^
361'
371'
Boom
Angle
(deg)
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
%
Plate 1
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
24.5
24.5
46.0
46.0
46.0
46.0
46.0
36.0
18.8
18.8
18.8
18.8
35.0
35.0
18.8
18.8
18.8
18.8
18.8
18.8
46.0
46.0
46.0
46.0
46.0
46.0
46.0
46.0
46.0
Open
Plate 2 or
Bottom Plate
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
31.0
31.0
46.0
46.0
46.0
46. D
18.8
18.8
18.8
18.8
18.8
18.8
18.8
36.0
18.8
18.8
36.0
18,8
18.8
18.8
18.8
24.5
0,
18.8
18.8
18.8
18.8
Tow
Velocity
(knots)
2.53
2.53
2.53
2.53
2.53
2.53
3.07
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
—
2.53
2.53
2.53
2.53
2.53
2.53
2.53
2.53
Oil
Applied
(gal)
3.8
10.0
20.0
3.85
3.75
18.0
18.0
4.5
4.5
10.0
10.0
4.5
4.5
10.0
9.44
4.5
4.5
4.5
4.5
3.82
3.65
—
4.14
4.03
3.74
3.98
4.09
4.57
4.57
4.20
3.88
4.29
4.52
3.84
5.59
4.27
4.49
Oil Retained
or Diverted
(gal)
1.8
—
2.0
0.69
0.6
1.98
0.48
1.56
2.38
	
	
1.72
1.45
0.56
0.75
1.94
1.02
	
0.77
2.69
2.63
—
3.28
2.74
2.77
3.12
3.44
3.95
4.06
3.76
3.44
3.66
3.82
3.28
4.68
3.36
3.52
% Oil
Retained/
Diverted
53b)
__b»c)
89b>
82b'C>
84d>
89d>
97e>
65£>
47f>
__f)
c,g)
62f)
68f>
94C)
92c)
50f)
63f)
__h>
68h)
70
72
—
79
68 (^
74
78
84
86
89
87
90
85
85
85
84
79
78
Test
Configurations
(see Figure 31)
A

A
A
A
A
A
A
A
B
B
B
B
B
B
B
B
B
C
D
D
E
E
E
E
E
F
F
F
F
F
F
GJ)
GJ>
Gj)
H
H
           48

-------
                              TABLE 1 (Continued)
NOTES
a)  Oil was applied inside the boom prior to towing.  This is a "constant
    volume test".  All other tests were constant flow rate tests.

b)  We observed a small oil loss under the forward curtain during deceleration
    of boom.

c)  We observed a slight oil sheen on the surface after the boom tow run.  This
    was lost under the boom.

d)  We detected only slight losses, less than c.

e)  We observed no losses.

f)  We observed oil dtoplets surfacing after the run, presumably lost under the
    boom.  The loss was greater than Note 4, and quite noticeable.

g)  This test was run to see if shorter flow control plates would be as effec-
    tive as the longer ones used in previous runs.  This is to simplify the
    design.  The shortened plates are used subsequently.

h)  A technician rode the skimmer to closely observe the oil loss mechanism.
    He saw numerous droplets below the surface inside the boom area.  Some of
    these droplets passed under the boom, accounting for the loss.

i)  Plate 2 was deleted, and a perforated bottom plate was added.

j)  This configuration was judged to be the best considering all factors.
                                       49

-------
                  ,Solid Boards to Prevent Ventilation (Typical)





         31"     /     ,                43"                .      24"
               7
17"
                                                    r
  Flow
 (A)   For Tests 1 through 9
          Plate 1 (Typical)
  Flow
                      Plate with 46% Open Area






(B)   For Tests 10 through 18
                                                                24"
  Flow
                               (C)  For Test 19
                        FIGURE 31 - TEST CONFIGURATIONS
                                      50

-------
                                                                       y   i
  Flow
             Configuration (D) for Tests 20 and 21
1 - .
-^__ 	
^— 1
17" 2" (Typ.)^p
1 ==>
'' Plate 2
— , 	 ; 	 ^a*^^/
""""""""""•fc.
"~"^^u""--»«fc_
"**'^*^»— "*^**-i
*^**L^ 	 ~"^^^
/•^Bl^^^
"-^'
,
Plate 1
s
i —
17"
^-^ 1
^ — "


14"
         Configuration (E) for Tests 22 through 26
          .31".

1 ^^^ 	 /

Uu "t —
2" -— -:*^
T ^^..^M,,, !

X S.C £. rVCIMVVCU
/ 	 2— I
.



T
14"
Flow
             Plate 1
                                                        Perforated Plate
                                                             Added
                      (F)  for Tests 27 through 32
                        FIGURE 31  - (Continued)
                                   51

-------
h-	19"
                              ;PI ate 2 Removed)
   2'
        Flow
                  Plate 1
             Non-Perforated



(G)  For Tests 33 through 35
                                 Plate 2 Removed
        	i	
    i
           P1OW                           Perforated




                    (H) For Tests 36 and 37 (shortened)
                      FIGURE 31 - (Continued)
                                         52

-------
                                    Four 19-Inch Horizontal Plates
                                    (2-Inch Spacing)
                                                       115"
Ln
               Flow
                       46% Open
                         Area
                                                                            18.8% Open
                                                                               Area
              FIGURE 32  - FINAL BOOM CONFIGURATION BEFORE FLOTATION IS ADDED (COMPARE WITH FIGURE 31G)

-------
                           VII.  CONFIRMING TESTS

TOW TESTS - HOUSTON

     Following the preliminary two-dimensional (2-D) tow tests described in
Section VI, a completely new, self-buoyant test device was fabricated.
Figure 4 shows a photograph of the four-foot wide high-current module.   Side-
walls (not shown) seal the sides of the boom for two-dimensional tow testing.
We found it quite difficult to achieve suitable flotation in the leading up-
stream half of the boom.  Only streamlined floatation could be used because
flotation having a large projected frontal area would disturb the flow of oil
(and water) into the boom.

     The Shell wave tank has an unusual shape, shown in Figure 33.  We were
able to achieve a relatively long tow run (100 foot test section) with the
four-foot-wide model, and the results of its tests are not affected by short
test-time problems (as confirmed by OHMSETT tests).  However, the tank's
effective length was too short for a 20-foot wide device (Figure D-l),  and
the oil losses observed (See Appendix D) were generally less than those found
later during tests at OHMSETT for all tow speeds above 2.0 knots (compare
Tables 2 and 5).

     In the 2-D tests at the Shell tank the four-foot-wide boom contained
85.2 percent of a 1.9 mm thick slick of No. 2 Fuel Oil at a 2.94 knot tow
speed.  In contrast, a conventional barrier of the same draft contained only
45.9 percent at a 2.25-knot tow speed (see Run Nos. 4 and 8, Table 2).  Six-
inch waves reduced the perforated-plate boom containment performance to 64,2
percent from a no-waves containment of 91.0 percent at approximately the
same tow speed (2.28 and 2.35 knots respectively, Runs 1 and 8).

     When Navy Special Fuel is used as the test oil, approximately 90 percent
containment effectiveness is achieved at 1.5 knots as compared with approxi-
mately 2.25 knots for No. 2 Fuel Oil (interpolate Runs 15 and 17 and compare
with Runs 1 and 2 respectively).  We feel that density (not viscosity) is the
primary reason for the observed difference in containment effectiveness  (See
Table 3).

     Tests were performed by towing the boom at a constant velocity through  a
100-foot long test segment, while applying oil on the water in front at  a
constant flow rate.  Figure 34 shows the test arrangement.  A remotely actu-
ated drop-curtain was attached between the forward ends of the sidewalls.
This curtain was dropped at the conclusion of the tow run to keep oil remain-
ing in the boom at the end of a run separate from that lost under the boom
during a run.  Oil losses from the boom were collected and measured after
each run.  Detailed procedures were essentially the same as those used  in  the
preliminary tow tests (See Appendix C).

                                      54

-------
     Table 2 contains test conditions and results for 18 tow runs included in
this test set.  Table 3 shows the test oil properties.  During the first four
tests using No. 2 Fuel Oil, the percentage of oil lost during a run compared
with that applied was less than 15 percent at speeds up to 3 knots, in the
absence of waves.  A 6-inch high, 2.8 second period wave increased the loss to
almost 50 percent at 3 knots.  Reducing the tow speed to 2.2 knots decreased
the loss to 35 percent in the presence of the wave.  If Test 10 is compared
with Tests 1 and 2, we see that the percent loss from the constant volume run
is almost half of that lost from the constant flow rate runs.  Thus oil losses
from inside the boom down through the bottom are about the same as those caused
by oncoming oil draining down the upstream face of the boom and underneath.

     Tests 12 through 17 were run using Navy Special fuel oil having a specific
gravity of 0.968 at 80°F [No. 2 Fuel Oil has a specific gravity of 0.858 at
this temperature].  Using densimetric Froude number scaling, (Equation (1)),
one can reduce the three-knot effectiveness of the boom with No. 2 Fuel Oil by
the ratio of the square root of oil-water density differences of the two oils
to find an equivalent result for Navy Special oil.  The calculated prediction
is that 15 percent of Navy Special oil should be lost at a velocity of about
1.4 knots:  Test 17 provides approximate proof of this scaling law.  A compari-
son of Run 16 with Run 14  (both at 2.3 knots) shows that losses were evenly
distributed betweep losses under the front face and losses through the sub-
merged perforated bottom for Navy Special oil.

     Tests 12 and 13 showed that with the denser Navy Special oil the deleteri-
ous effects of waves (in the 2-D tests particularly) were significant.  Later
tests at OHMSETT revealed that waves were not as much of a problem as encoun-
tered in these tests.

     Finally, Test 18 was run to show that without the perforated baffle
assembly in front of the downstream barrier, significant oil losses would
occur.  Comparing Tests 1 and 18, we see clearly that at about 2.3 knots the
high current boom lost only 9 percent whereas the "baffle-less" boom of the
same draft lost 54 percent of the oil applied.

THREE-DIMENSIONAL TOW TESTS - OHMSETT

     The principal confirming tests were conducted at the U.S. EPA's Oil and
Hazardous Materials Simulated Environmental Test Tank (OHMSETT) Facility at
Leonardo, New Jersey".  This 65-foot wide tank is 667 feet in length, so that
relatively long test runs - in excess of 90 seconds at 3.5 knots - are possi-
ble.  A more detailed summary of OHMSETT is included in Appendix E.

     Primary emphasis of the OHMSETT tests of the high-current boom was on
diversionary test runs, since the Shell tank was considered  too short  for
reliable tests with wide oil control devices.

     The objective of the tests was to obtain quantitative oil diversion effi-
ciency data at tow speeds  (and hence water currents) of 2.5  knots  and  above.
A four-foot-long section of high current boom was assembled  in a single rigid
module for these tests.  Figure 1 shows the boom under tow in  the  tank during
a typical test run.  A sketch of the boom mooring arrangement  and  overall  tank
dimensions is included as Figure 35.  The boom profile is identical  to that
                                       55

-------
                                   N
Ui
OS
          DRIVE
        MECHANISM,
             TOW WINCH
WAVE ABSORBER
      IL APPLICATION  NOZZLE

    FWD DROP
    CURTAIN
                                                                  Ti i i i i iTi ^     si
                                                                   OIL STORAGE
                                       FIGURE 33 - BOOM TEST SET-UP HOUSTON IN WAVE/TOW TANK

-------

FIGURE 34 - BOOM SECTION DURING TOW TESTING.   SIDE WALLS,  FORWARD  DROP
            CURTAIN AND OIL PIPING ARE ADDED  FOR TEST PURPOSES

-------
                                       TWO-DIMENSIONAL BOOM TOW TESTS - FOUR-FOOT WIDE SECTION

                                                               TABLE 2
oo
Run
No.
1
2
3
4
5
6
7
8
9
10b)
11
12
13
14
15
16b)
17
Boom
Angle
(dee)
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
90
Test Oil
No. 2 Fuel Oil
tt
11
It
11
tt
It
It
tt
tl
tt
Navy Special
tt
it
it
ti
tt
Navy Distillate8'
Tow Contact Wave
Velocity, Time f ) Height
(knots) (sec) (in.)d>
2.35
2.39
2.94
2.94
2.99
1,31
2.19
2.28
1.72
2.19
1.69
1.75
2.26
2.28
1.79
2.29
1.37
2.28
-
-
-
-
6"
-
6"
6"
6"
-
6"
6"
6"
-
-
-
-
Oil
Period Applied ,
(sec) (gal.)
19.4
20.7
18.5
16.3
17.2
22.0
19.4
17.0
24.9
16.0
2.17
21.8
19.7
21.1
20.7
16.6
26.9
21.1
Equivalent Oil Retained/
Thickness Diverted
(mm)e> (gals.) %
2.0
2.1
1.9
1.7
1.8
2.2
2.0
1.7
2.5
1.6
2.2
2.2
2.0
2.2
2.1
1.7
2,7
2.1
17.66
18.55
15.76
13.88
8.93
21.78
12.77
10.91
15.96
15.37
17.19
9.60
5.80
8,10
16.55
13.67
24.77
9.68
91.0
89.6
85.2
85.2
51.9
99.0
65.8
64.2
64.1(
96.1
79.2
44.0
29.4
38.4
80.0
82.3
92.1
45.9
            a) Detectable loss around sides made  this high.
            b) "Preloaded" run using 16 gal. oil  from previous run.  This was run to show
            c) Baffles were removed; a straight vertical board was placed at the same 14"
               occurred when baffles are not used.
            d) Wave steepness, H/L = 1/40.
            e) Calculation based on a slick 4 feet wide.
            f) Time boom under tow is in contact with test oil.
            g) Navy distillate oil has the same properties as No. 2 Fuel Oil.
amount lost through bottom holes.
draft to see how much loss

-------
                                    TABLE 3


                         MEASURED TEST OIL PROPERTIES
                                  SHELL TESTS
                   Relationship of;
Surface Properties at 77°F
Oil Type
Navy Special
Fuel Oil
(MIL-F-859E)

No. 2
Fuel Oil

Temp.
(°F)
100
75
50
100
80
60
Specific
Gravity
0.9606
0.9688
0.9722
0.8500
0.8578
0.8653
Viscosity
(cs)
86
201
593
2.7
3.5
4.5
Surface Interfacial
Tension Tension
(dyne/cm) (dyne/cm)
32.4 19.2a)

28.0 27.0c)

Equilibrium
Thickness
(mm)
4.90b)



a) tap water
b) NRL film and tap water
c) distilled water
                                      59

-------
                Perforated
                Plate Boom
                                                      Forward Bridge
                                                      t
       Bridge
       Travel
   Aft Bridge
' (Tied to  Forward)
FIGURE 35 - SKETCH OF BOOM MOORING SYSTEM USED FOR OHMSETT TESTS
                                  60

-------
shown previously in Figure 4, since ten four-foot-wide segments were bolted
together to form the 40 foot section.

     Both containment  (90° to the tow direction) and diversion tests (at 45°)
were run at speeds from 2.2 to 3.5 knots.  Test oils, described further in
Table 4 were  (a) slightly emulsified Sun 75 lube oil and (b) No. 2 Fuel Oil.
The oils were applied  at a constant flow rate (with multiple nozzles) on the
water in front of the  advancing boom.  The approximate run time for each test
was 90 seconds.  Additional test information and photos are included as Appen-
dix F.

     Efficient diversion (30 percent or less oil loss under or over the boom)
was achieved using the denser Sun 75 oil at a tow speed of 3.5 knots and a
diversionary angle of  45°.

     In the containment mode the pitch angle set by the rigging is critical
for highest efficiency.  Initial containment tests were completed before a
rigging error was detected.  This problem, we believe, accounted for the
boom's flooding at tow speeds above 2.3 knots during these containment tests.
Unfortunately, this problem was not determined in time to permit re-running
the affected tests.  Extrapolations to higher velocities can be made, however,
using previously obtained 2-D test data.  This rigging error has been corrected
in the final boom design shown in Figure 6.

     The OHMSETT test  results formed the basis for the projected high-current
boom performance summary shown previously in Figure 5.  Extrapolations to oil
types and diversionary angles not tested were made using the generally accepted
densimetric Froude scaling law.

     A summary of the  test procedures used includes the following steps for a
given tow test:

     1.  Start the wave generator (if waves are called for).

     2.  Accelerate the tow bridge and hence the high current boom
         to the desired tow speed.

     3.  Start despensing oil through the nozzles once the boom has
         reached a steady-state velocity.

     4.  Mark the start of the actual test run when oil first reaches
         the boom.

     5.  When the applied oil has contacted the boom for a 90 second
         period quickly stop the bridge, hence the boom and hence
         the oil losses (if any) under the boom.

     6.  Then quickly  stop the oil application and the wave generator.

     7.  Manually collect and measure only that oil lost under  or over
         the boom before it could be diverted.  Diverted oil and oil
         remaining within the boom at the end of the run are not counted
         in the oil loss measurement.
                                       61

-------
     8.  Record sufficient data to determine (a) the oil application
         rate (b) the width of the slick approaching the boom and
         (c) the quantity of oil lost in addition to the usual records
         of tow speed and wave condition.

     In this summary we assume that the boom has been rigged for towing and
that the controlled variable settings have been made.  Actual oil losses were
concentrated for skimmer collection using the trailing separating boom (used
to separate oil leaking under the boom from that successfully diverted by
high-current boom) to encircle the lost oil.

     A summary of the test results is shown in Table 5.  Initially the 40-foot
boom segment was placed at a 45° angle with the tow vector.   Using Sun 75 oil,
the first three tests explored the effects of increased velocity on the ability
of the boom to divert oil.  At 3.5 knots the diversion effectiveness reduced
to 70 percent, meaning that 30 percent of the applied oil was lost under the
high-current boom.  Losses above 30 percent have been arbitrarily selected as
being too high for efficient diversion.  At 3 knots the losses were only
5 percent.  Tests 4 and 5 indicate that 6-inch, 3 second period waves do not
appreciably affect the diversion effectiveness of the boom.   Eight-inch, 2
second waves applied in Test 6 were more choppy than the 6-inch, 3 second
waves and a small reduction in performance is noted.

     The boom was rerigged to allow towing at a 90° diversion angle (contain-
ment mode) and additional tests with Sun 75 oil were run.  During an aborted
test run (not included in the table) in which the oil application pump stopped
midway into the run, the boom began to submerge.  Poorly rigged cable
moorings - the more likely candidate to cause the bow to dip and accumulate
more water than can be relieved through the bottom perforations of the boom - -
were not suspected.  Consequently the test program proceeded, and the two 90°
tests (Tests 7 and 8) were run at reduced velocities to avoid boom submergence.
At 2.3 knots, the limiting velocity to avoid submergence, 84 percent of the
oil was successfully retained by the boom.  Assuming that the normal component
of velocity to the boom caused the oil loss, one can use the Test 3 results at
45° to predict a 70 percent oil retention at 2.5 knots at 90°.  This prediction
is further substantuated by referring to Table 2 which contains earlier 2-D
test results conducted in Houston.  In that table the oil loss results for the
first four tests suggest that 90 percent retention capability should be
expected at speeds above 2.3 knots.  The percentages shown in Tables 2 and 5
differ slightly because the Houston test runs were shorter and less oil was
lost during the runs.  Also Table 2 shows that the same boom profile as used
in these tests was successfully tested in Houston at 3 knots - but the test
rigging there did not cause the boom to submerge.

     Test 9 revealed that a 6-inch, 3 second wave did not alter the boom per-
formance at about the same tow speed.  An 8-inch, 2 second wave was not tested
on the 90° boom because the boom's dimensions were such that it resonated.

     The last two test runs were made using No. 2 Fuel oil as the test oil and
arranging the boom to a 45° diversion angle.  The diversion effectiveness  in
these tests was about the same as that obtained earlier with the Sun 75 oil.
This result is not surprising because the specific gravities  of  the two oils
are almost the same  (Sun 75 oil is much more viscous  than  fuel oil, however).
                                       62

-------
                                    TABLE 4
                         MEASURED TEST OIL PROPERTIES
                                 OHMSETT TESTS
                   Relationship of:
Surface Properties at 88°F
Oil Type
Sunvis 75
(8 to 9%
water)
No. 2
Fuel Oil
(5% water)
Temp.
(°F)
80
60
80

60
Specific
Gravity
0.9030
0.9111
0,8470

0.8480
Viscosity
(cs)
317
578
7.1

8.9
Surface
Tension
(dyne/ cm)
30.8

28.8b)


Interfacial
Tension
(dyne/cm)
I3.8a)

13.6a'b)


Equilibrium
Thickness
(mm)





a) salt water
b) at 80°F
                                      63

-------
                                       HIGH CURRENT BOOM TESTS AT  OHMSETT
                                                     TABLE 5
                                                     RESULTS
Run
No.
1
2
3
4
5
6
7e)
8e)
9
10
Boom
Angle3) Test
(deg.) Oil
45 Sun 75
45 "
45
45
45
45
90
90
45 No. 2
45 No. 2
Tow
Velocity
(knots)
2.0
3.0
3.5
2.5
3.25
3.0
2.3
2.2
3.0
3.0
Contact
Timeb'
(sec)
75
54
60
60
60
60
60
60
60
60
Wave
Height Period
(ins) (sec)
-
-
-
6
6
8
-
6
-
8
-
-
-
3
3
2
-
3
-
2
Oil
Applied
(gal)
194
208
381
280
299
300
371
339
404
427
Equivalent
Thickness0*
(mm)
1.0
0.8
0.9
0.9
0.9
0.9
1.6
1.6
1.5
1.4
Oil Retained
or Diverted
(gal)
— »
i
-
265
263
257
264
214
284
-
-

«iood)
90d)
70
94
86
88
85
84
87d)
85d)
Footnotes:
          a)  Angle is between boom and  tank sidewall.
          b)  Time boom under tow is in  contact with test oil.
          c)  Based on 30-foot slick width.
          d)  Estimated.
          e)  Rotating mooring cables caused boom to pitch downward, then the increased flow submerged the
              stern at speeds in excess  of 2.3 knots.  This can be easily corrected.

-------
                                VIII.  REFERENCES

 1.  Ayers, R. R. , "Developing An Open Seas Skimmer",  prepared by Shell
     Development Company for the American Petroleum Institute, Final  Report
     Contract No. OS-5C, May, 1975.

 2.  Wicks, M., "Fluid Dynamics of Floating Oil Containment by Mechanical
     Barriers in the Presence of Water Currents", presented at API-FWPCA
     Joint Conference on Prevention and Control of Oil Spills, New York,
     December, 1969.

 3.  "Concept Development of a Heavy Duty Oil Containment System for  Use on
     the High Seas.  Volume I", prepared by Atlantic Research Corporation  for
     the U. S. Coast Guard, Contract DOT-CG-00-492-A,  Final Report, January,
     1971.

 4.  Houser, J. R., Editor, "Lightweight Oil Containment System - Low Tension
     Barrier System", prepared by Wilson Industries, Inc. for the U.S.  Coast
     Guard, Part I, Final Report, January, 1971.

 5.  Miller, E., Lindenmuth, W., and Altmann, R., "Analysis of Lightweight
     Oil Containment System Sea Trials", prepared by Hydronautics, Inc.  for
     the U.S. Coast Guard, Report No. CG-D-22-74, Interim Technical Report,
     October, 1973.

 6.  "Oil Spill Containment and Removal System-A Feasibility Study",  prepared
     by the Garrett Airesearch Manufacturing Company for American Petroleum
     Institute, Project Sea Dragon, Contract No.  API OS-5, Final Report,
     December, 1970.

 7.  March, F.A., and Beach, R. L., "High Seas Oil Recovery System",  presented
     at the API-EPA-USCG Joint Conference on Prevention and Control of Oil
     Spills, Washington, D. C., March, 1973.

 8.  Bianchi, R. A., Farrell, J. H, and Johanson, E. E., "Demonstration of
     Fixed and Moving Inclined Plane Oil Skimmers for Collecting Oil Under the
     Water Surface", presented at the 1972 Offshore Technology Conference,
     Houston, Texas, May, 1972.

 9.  Jensen, D. S., "U.S. Coast Guard Fast Current Oil Removal System Develop-
     ment Program", presented at the 1973 Offshore Technology Conference,
     Houston, Texas, May, 1975.

10.  Dorrler, J. S., Ayers, R., and Wooten, D. C., "High Current Control of
     Floating Oil", 1975 Conference on Prevention and Control of Oil Pollution
     Proceedings, San Francisco, California, March 25-27, 1975.

                                      65

-------
                                  APPENDIX A

                    DETAILS OF STUB-TUBE BAFFLE EXPERIMENTS

                             (SM-1 through SM-31)

     A detailed step-by-step summary of the individual stub-tube model baffle
experiments run in the Shell Current Tank (Figure 26)  is found in Table A-l.
Figures A-l and A-2 show the configuration profiles, and Tables A-l (for test
SM-1 through SM-11) and A-2 show the principal dimensions.  Figures A-3 through
A-34 are selected photographs taken at various states of experimentation.
                                       66

-------
                                                                     TABLE A-l

                                                         EXPERIHENTS WITH STUB TUBE ARRAY
Test
No.
Sl*-l


SM-2

SM-3


SM-4




SM-5


SM-6




Sia-7

No.
Tubes/
No.
Rows
51/6


51/6

51/6


63/8




68/8


42/6




56/8

Size Z X
Tubes Spacing Spacing
Inches Inches Inches
.84 2.0 2.0


.84 2.0 2.0

.84 2.0 3,3,2,2,2


.84 4 (1st row) 4,4,3,3,
2-3/8 (2nd 2,2,2
row)
3 (all
others)
.84 2.0 2.0


.84 2.5 5.0




.84 2.5 2,2,4,5,
5,5,5
X Axis
Y To 1st
Draft Row (j_
Inches Inches
6.0 31.0


6.0 31.0

6.0 31.0


6.0 23.0




6.0 33.0


6.0 30.0




6.0 29.0

Vel.* Ref.d)
Front/Back Vel.
fps fps
1.17/21(1) 1.05


2.26/.60(1) 2.1

2.29/.66(1) 2.1


2.27/61(1) 2.15




2.18/.57(1> 2.15


2.32/.90(3) 2.15




-/- 2.15

A H
Level See
Inches Figure Remarks
1.0 A-3- Look promising, did not
A-5 pull sawdust under (top
observation only) .
1.0 A-6 Increased surface
turbulence .
1.0 Installed glass side and
saw bubbling action, AH
and turbulence.
1.0 Observed turbulence at
1st (3) rows and bub-
bling ventilation action.


1.0 Reduced vortex action
but still lost sawdust
under .
.75 Downstream current did
not decrease as needed,
large amounts of turbu-
lence were observed.

A-21 Vortices still predomi-
nate, hand held tubes
Decision
Look at 2.0 fps.


Increase X-spacings.

Increase spacing of
tubes upstream.

Check original with
8 rows of tubes.



Increase tube spac-
ing.

4 rows 2"(^ , 4 rows
5"q, (SM-7) Alter
spacing to avoid
localities of turbu-
lence at front.
Decided to hand hold
individual tubes
                                                                                                   between rows  1 & 2  and
                                                                                                   2 & 3 reduced vortex
                                                                                                   action.
using metal fins and
streamers to reduce
air ventilation
bubbles and down-
draft flow.
	                                   1234
*Vel in  front  at  X = 0,  Vel in back at X - 48 , X - 51 ,  X = 56 , X = 54
     Hand  held a  row of  0.84 inch tubes (2" transverse spacing) in front of seven rows of 0.84 inch tubes (2"  spacing both  axes):
     (a)   With 3  fins on each tube of the first row, the turbulence was minimized if the row of tubes was inclined 30° upstream from vertical.
     (b)   With the row pointing upstream as in (a) a second row of tubes with fins was placed in front using a 25" downstream angle.   Turbulence
           was  reduced but particles became entrapped between the second row of fins an- the first row of vertical tubes.  These particles  were
           caught  in an upstream flow.
     (c)   The  current was Increased to 2.4 fps and turbulence increased.  After the fins were removed from the second row (with the  upstream
           angle)  the turbulence decreased.
     (d)   This is measured velocity for the scale model.   The equivalent velocity for full scale may be obtained by the formula.

-------
                                                                              TABLE A-l

                                                            EXPERIMENTS WITH STUB TUBE ARRAY (Continued)

Test
No.
No.
Tubes
No.
Rows
Size
Tubes
Inches
Z
Spacing
Inches
X
Spacing
Inches
Y
Draft
Inches
X Axis
To 1st
Row %
Inches
Vel.*
Front/Back
fps
Ref.d>
Vel.
fps
AH
Level
Inches

See
Figure Remarks

Decision
CO
         Single Tube Experiments:

         Hand held individual tubes to observe water  flow:
              (a)  .84" dia. tube with (1)  fin -  fin  1"  max.  under H20 looked good,  deeper  created Vortices
              (b)  .84" dia. tube without fin created vortices,  upstream angle looked  good
              (c)  .84" dia. tube with streamer - looked good no vortices
         Hand held rows 2"(J] (8 tubes each)  in front of 7 rows of 2:  apart axis of  alternating 9  and  8  tubes  each  2"
-------
        Ho.
      Tubes/
Test    "No.
 No.   Rows
 Size      Z
 Tubes  Spacing
Inches  Inches
                   X
                Spacing
                Inches
   Y
 Draft
Inches
X Axis
To 1st
Row q,
Inches
                                                                     TABLE A-l

                                                              TEST SUMMARY STUB TUBES
  Vel.*     Ref.
Front/Back   Vel.
   fps	fps
                                                          d)
Barrier Location   See
X-Inches/Y-Draft  Figure
                                                                                                              Remarks
                                                                                                                                   Decisions
SM-12  76/9
SM-13  76/9
SM-17   76/9
SM-18   76/9
SM-19   76/9
 .84
 .84
         2.0
         2.0
                 11,4,2,
                   2? •> •)
                  »^>^»^
 .84
         2.0
.84     2.0
                .84     2.0
                                           6.0
                                           6.0
                                                  18.0
                                                  18.0
                    -/-
                                              -/-
                             6.0     18.0
                    -/-
                                           6.0    18.0
                                           6.0    18.0
                                             -/-
                                             -/-
                                                                      1.05
                                                                      1.05
                                                       2.0
                                                                      2.0
                                                                      2.0
                                                                               60
                                                                               72
SM-14
SM-15
SM-16
76/9
76/9
76/9
.84
.84
.84
2
2
2
.0
.0
.0
11
II
(1
6.0
6.0
6.0
18.0
18.0
18.0
-/- 1.
-/- 1.
-/- 1.
05
05
05
69
66
63
4
4
4
                                                                60
                                                                               58
                                                                               66
                                                                      1/2-8
                                                                                        2-3
                                                                                       2"-6"
                                                                                A-29   A 6" draft on bar-
                                                                                A-30   rier causes forward
                                                                                       currents and turbu-
                                                                                       lence, a 4" draft
                                                                                       decreases action.

                                                                                       A 4" draft causes
                                                                                       forward currents;
                                                                                       and a 2" draft
                                                                                       decreases the
                                                                                       currents.
                                                      Upward turbulence
                                                      was almost eliminated
                                                      at boom.

                                                      1" draft  of barrier
                                                      was too shallow,
                                                      2"-8" - No vortices,
                                                      but turbulence in-
                                                      creased as depth
                                                      increased.

                                                      A barrier draft of 3"
                                                      caused too much tur-
                                                      bulence;  at 2",
                                                      turbulence was
                                                      decreased.

                                                      Boom draft of 2-8"
                                                      caused upward cur-
                                                      rents at  barrier  on
                                                      occasions with a  6"
                                                      draft causing vorti-
                                                      ces to form.
                                                                                                                             Place barrier further
                                                                                                                             back.
                                                                                                                            Move barrier  closer.
                                                                                                                            Increase velocity.
                                                                                                              Move barrier closer
                                                                                                              to tubes.
                                                                                                              Move barrier further
                                                                                                              away from tubes.
                                                                                                              Go to larger OD P.V.C.
                                                                                                              tubes.

-------
                                                                     TABLE A-l

                                                        TEST SUMMARY STUB TUBES (Continued)


Test
No.
No.
Tubes/
No.
Rows

Size
Tubes
Inches

Z
Spacing
Inches

X
Spacing
Inches

Y
Draft
Inches
X Axis
To 1st
Row £
Inches

Vel.*
Front /Back
fps

Ref.d>
Vel.
fps


Barrier Location
X-Inches /Y-Dr af t


See
Figure Remarks



Decisions
 SM-20  48/8
 SM-21  48/8
SM-22   48/8
SM-23   48/8
 1.31     3.0      3.125     9.0    24.0
 1.31     3.0      3.125     9.0    24.0
 1.31     3.0      3.125     9.0    24.0
1.31     3.0       3.125     9.0    24.0
SM-24   7€/9     0.84    2.0
SM-25  76/9    0.84     2.0
SM-26  76/9
                  1.0 (1st   6.0    20.0
                     row)
                                 2.0       6.0    20.0
0,84    2.0      2.0        6.0    20.0
                                                                      2.17
                                                                      2.17
                                                       2.17
4.0
                                                                      3.9
                                                                      2.1
                                                                      2.6
                                                                               63
                                                                               75
                                                                87
                                                                75
                                                                               64
                                                                               66
                                                                               66
                                                                                       4-15
                                                                                       4-10
                                                                        5-12
                                                                                       3-8
                         A-31
                         A-32
Draft of barrier had
very little effect
on surface of H,0.
Did not lose beads
at this setting.

With a boom draft of
10", vortices tried
to form but would not
pull beads under.

At a boom depth of
11-12", forward cur-
rents were created
and should be maxi-
mum depth placement
of boom.

Placing a rear bar-
rier with a draft of
6" at X = 75" caused
severe ventilation
and turbulence.

Placing a 3 to 8"
barrier at X = 64"
caused interference
waves between the
tube array and the
barrier.
                                                                                        Plastic beads  of  0.9  Try higher velocity.
                                                                                        specific  gravity  were
                                                                                        presented and  85%
                                                                                        were retained  by  the
                                                                                        "boom.
                                                                                                                             Increase distance
                                                                                                                             between tubes and
                                                                                                                             boom.
                                                                                                                             Move barrier further
                                                                                                                             away from tubes.
                                                                                                                             Results not as good
                                                                                                                             as SM-21.   Try con-
                                                                                                                             figuration of SM-21
                                                                                                                             at a higher velocity.
Go back to the 0.84"
tube array.
Try even tube spacing.
                                 Approximately 80% of
                                 the beads were re-
                                 tained by the boom.
                      Vary the barrier
                      draft.

-------
                                                                    TABLE A-l

                                                       TEST  SUMMARY STUB TUBES (Continued)
        No.                                     X Axis
      Tubes/  Size      Z         X        Y    To 1st     Vel.*    Ref.
Test    No.   Tubes  Spacing   Spacing   Draft  Row 4   Front/Back   Vel.
 No.   Rows  Inches  Inches    Inches    Inches  Inches	fps	fps
                                                                        d)
                                                                            Barrier  Location   See
                                                                            X-Inches/Y-Draft Figure
SM-27
SM-28  54/9    1.31
SM-29
                        3.0
                                Same as  SM-25
                                17 (1st    8.25
                                  row)
                                3.125 (all
                                 others)

                                Same as SM-28
                                                  18.0
SM-30  64/9    1.31    3.0      17 (1st     9.4     18.0
                                  row)
                              3.125 (all
                                 others)
SM-31
                                Same  as  SM-30
3.0       66      3-6             At 3.0 fps and 3"
                                  draft, 60% of the
                                  beads were retained
                                  for separate runs.

2.5       77       8      A-33     With rear barrier at
                                  20" and 8" draft,
                                  90% of beads were
                                  retained.

2.9       77       8              An increase in velo-
                                  city to 2.9 fps
                                  resulted in a reten-
                                  tion percentage of
                                  80.

2.95      81       9              80% of the beads
                                  were retained.
                                                                                              A-34    A single board was
                                                                                                      placed horizontally
                                                                                                      between the first two
                                                                                                      inclined rows of
                                                                                                      tubes to eliminate
                                                                                                      downward turbulent
                                                                                                      flow.  Bead retention
                                                                                                      was 93%.
                                                                                                                             Return to  the 1.31"
                                                                                                                             tube  array model.
                                                                                                                            Try higher velocity.
                                                                                                                            Try deeper draft
                                                                                                                            tubes and place
                                                                                                                            barrier further
                                                                                                                            downstream.

-------
                                  TABLE A-2
TESTS SM-1 THROUGH SM-11:
Use
Figure
A-l configuration and
Table A-l Dimensions
TESTS SM-12 THROUGH SM-31:
Test
No.
SM-12
SM-1 3
SM-14
SM-15
SM-1 6
SM-1 7
SM-18
SM-1 9
SM-20
SM-21
SM-22
SM-23
SM-24
SM-25
SM-26
SM-27
SM-28
SM-29
SM-30
SM-31C
Vel.
FPS
1.05
1.05
1.05
1.05
1.05
2.0
2.0
2.0
2.17
2.17
2.17
4.0
3.9
2.1
2.6
3.0
2.5
2.9
2.95
2.95
In.
18
18
18
18
18
18
18
18
a
a
a
b
20
20
20
20
18
18
18
18
In.
29
29
29
29
29
29
29
29
a
a
a
b
32
32
32
32
35
35
35
35
X3
In.
33
33
33
33
33
33
33
33
24
24
24
24
35
35
35
35
38
38
38
38
x4
In.
45
45
45
45
45
45
45
45
46
46
46
46
47
47
47
47
57
57
57
57
X5 X6
In. In.
60
72
69
66
63
60
58
66
63
75
87
75
64
66
66
66
77
77
81
81
Y4
In.
6
6
6
6
6
6
6
6
9
9
9
9
6
6
6
6
8.25
8.25
9.4
9.4
In?
4
4
4
4
4
l/2"-8"
2"-3"
2"-6"
4"-15"
4"-10"
5"-12"
6
3-8
6
6
3-6
8
8
9
9
a)  The tubes for row X  were absent in these runs and the row for X_  is
    vertical.
b)  Inclined tubes were not used.
c)  Board placed between X.. and X~ in a horizontal position.
                                     72

-------
                       TANK WALL
    +Z
  FLOW
                    TUBE ARRAY
                    (PVC PIPE)
                PLYWOOD
              SIDE  BOARD  (TYP)
POSTS FROM ABOVE  TO
RESTRAIN SIDE BOARDS


  CURRENT TANK WINDOW
X
   TANK WALL
                                 PLAN VIEW
                                                                        72"
                            PLEXI6LAS WINDOW
                m
                                                                 18"  DRAFT
                         PROFILE VIEW ALONG X-AXIS
     FIGURE A-l  - SKETCH OF STUB-TUBE ARRAY BAFFLE TEST CONFIGURATIONS
                  FOR TESTS SM-1  THROUGH SM-11.   (SIDE BOARDS PREVENT
                  3D EFFECTS.)
                                     73

-------
96"

*

- *3

L-« x? »-
XT
* ^»l Tnhn"

X5




v V V
- A/
Fins(3ea.)
X6












^^^


Tubes












-

-

I 1
^ *5
T 1

••"

Broom
/





x'Sideboard
\^
«^

^C \



24"
                                                         Trailing  Board
      Flow
FIGURE A-2 - SKETCH OF STUB-TUBE BAFFLE TEST CONFIGURATION FOR TESTS
        SM-12 THROUGH SM-31.   (SIDE BOARDS PREVENT 3D EFFECT)

-------
FIGURE A-3 - SM-1;  1.05 FPS .84"  OD TUBES
    FIGURE A-4 -  TEST SM-1;  1.05  FPS
                    75

-------
FIGURE A-5 - TEST SM-1;  1.05 FPS
 FIGURE A-6 -  TEST SM-2;  2.1  FPS
                76

-------
FIGURE A-7 - SINGLE TUBE HAND HELD  OBSERVATIONS
 FIGURE A-8 - SINGLE TUBE UPSTREAM ANGLE (35
                       1

-------
FIGURE A-9 - SINGLE TUBE WITH FIN 1"  DEEP,  NO  VORTICES
    FIGURE A-10 -  SINGLE  TUBE WITH  FIN,  TWO  INCHES
               DEEP,  VORTICES APPEARING
                            -

-------

 FIGURE A-11 - SINGLE ROW OF TUBES IN FREE STREAM, VORTICES

FIGURE A-12 - SINGLE ROW OF TUBES  WITH  STREAMERS, VORTICES
                             •

-------
FIGURE A-13 - TOP ROW, LEFT TO RIGHT:  TUBE WITH 3 FINS,
              TUBE WITH SINGLE FIN,  TUBE (ONLY).
              TUBE WITH STREAMER.
              SECOND ROW:  ROW OF TUBES WITH FINS, ROW
              OF TUBES WITH STREAMER
 FIGURE A-14 - SINGLE TUBE WITH STREAMER, NO VORTICES
                          80

-------
FIGURE A-15 - ROW OF TUBES WITH STREAMERS IN AN UPSTREAM
              ANGLE IN FRONT OF 6 ROWS ON 2" /'. TO {~
      FIGURE A-16 - AS ABOVE ONLY DOWNSTREAM ANGLE
                          81

-------
    FIGURE A-17 -  SINGLE  ROW OF  TUBES  WITH  FINS  IN  FREE
                  STREAM  -  VERY  LITTLE TURBULENCE


FIGURE A-18 - ROW OF TUBES WITH FINS AT A DOWNSTREAM ANGLE
                             •-

-------
FIGURE A-19 -  ROW OF TUBES  WITH  FINS,  UPSTREAM ANGLE
   FIGURE A-20 - SAME AS ABOVE ONLY  DEEPEN  DRAFT
                       83

-------
FIGURE A-21  - TEST SM-7, 2.15 FPS
FIGURE A-22 - TEST SM-8, 2.1 FPS


-------

 FIGURE A-23 - TEST SM-8, 2.1  FPS
FIGURE A-24 - TEST SM-8, 2.1 FPS
                 ;;

-------
  ."V;
   " '

FIGURE A-25 - SM-9, ARRAY OF 1.076" OD TUBES
        FIGURE A-26 - SM-9, 1.95 FPS
                      86

-------
       -.. ^

        fel            5 i3!^'

       ^i • r          fV
          M i-> I* Vl    :^ •
             I  -  ~j» 3»

FIGURE A-27 -  1.314" OD TUBES USED FOR TEST 10 AND 1

         FIGURE A-28 - SM 10,  2.05 FPS
                     87

-------
   FIGURE A-29  -
TEST SM-12, 1 05 FPS
BOOM 15 INCHES BEHIND BOOM
FIGURE A-30-  TEST SM-12, ,.05 FPS

-------
 FIGURE A-31 •  TEST SM-24, BOON 6" DEEP, 3.9 FPS
FIGURE A-32 - TEST SM-24,  BOOM 3" DEEP,  3.9 FPS


-------
   FIGURE A-33 - TEST SM-28, 8.25" DRAFT ON TUBES
FIGURE A-34 - TEST SM-31, HORIZONTAL BOARD IN PLACE,
              9.4-INCH TUBE DRAFT
                         •-•

-------
                                  APPENDIX B

                DETAILS OF PERFORATED-PLATE BAFFLE EXPERIMENTS

                             (IPM 1 through IPM 33)

CONFIGURATION STUDIES

     A detailed step-by-step summary of the individual inclined, perforated
plate baffle experiments run in the Shell Current Tank is found in Table B-l.
Figure B-l shows the configuration profiles and Tables B-2 and B-3 contain the
principal dimensions.  Figures B-2 through B-32 are selected protographs taken
at various stages of experimentation.

FLOW ANALYSIS - FINAL CONFIGURATION

     At the conclusion of the model tests a detailed flow analysis of the
inclined plate profile (see Figure B-33) was made.  A Thermo Science Incorpo-
rated (TSI) hot wire anemometer probe was used to measure discrete points in
the velocity field caused by the boom profile.  In this current tank test the
free-stream velocity was set at 4.8 fps (2.8 knots).  The TSI probe was placed
at predetermined points to measure the velocity.  Figure B-34 shows the mea-
sured points on the profile found by passing a vertical plane through the boom
such that the plate is parallel to the free-stream current vector.  Figure B-35
contains measurements taken on a horizontal plane three inches below the
water's surface.

     Point velocities shown in the two figures indicate that the effect of the
two perforated, inclined plates is that of creating a low velocity region just
in front of the aft barrier.  Variations in readings where symmetry should
show identical results can be explained by flow variations and surges in the
test tank.
                                        91

-------
                                                                   TABLE B-l

                                                    SUMMARY OF PERFORATED-PLATE  BAFFLE TESTS

              Angle  Front  of   Back  of   Draft  of   Ref.    Vel.   Vel.         Boom
Test     %     of     Plate    Plate    Plate    Vel.  x =  0  x/fps   Location/Draft   See
 So.   Open   Plate  x =  in.    x  = in.   y = in.    fps     fps   in./fps	in./in.     Figure
                                                                                                          Remarks
                                                                                                                                Decisions
IPM-1A   46%
IPM-1B   18.
               18°
                 18°
1PM- 1C   18.8%   18°
IPM-2A   18.8%    18°
IPM-2B  18.
IPM-3   18.8%   18°
                         39
                         39
                         39
                         39
               18°     39
                       39
IPM-4   18.8%    18°      39


IPM-5   18.8%    18°      39



IPM-6   18.8%    18°      39


IPM-7   18.8%    18"      39
69       10      2.20   2.21  87/1.65


69       10      2.20   2.21  S7/.47



69       10      2.20   2.21  S7/.24




69       10      2.25




69       10      2.25





69       10      2.25   2.26  63/.21


69       10      2.25   2.26  78/.4S


69       10      2.25   2.26



69       10      2.25


69       10      2.25
            1-7


            8,9



           10,11




69/10




69/10





71/10        12


84/10        13


96/6



69/10


78/10      14,15
                                                                                                Only 25% reduction in    Reduce open area.
                                                                                                current.

                                                                                                Observed some ventila-   Place board @ water-
                                                                                                tion but would not       line to reduce venti-
                                                                                                retain beads well.       lation.

                                                                                                Stops ventilation but    Try open-bottomed coke
                                                                                                would not retain beads   crate without board.
                                                                                                well.                    Also insert rear
                                                                                                                         barrier.

                                                                                                Used coke box; surface   Use board rather than
                                                                                                of H,0 turbulent but no  coke case, because less
                                                                                                  loss of beads.
                                                                                                                           surface  turbulence
                                                                                                                           occurs.
                                                                                                  Used board covering  1st  Look at ventilation on
                                                                                                  12 inches  of  holes;  cor- upper  part of  inclined
                                                                                                  ner vortices  formed  and  plate  without  board but
                                                                                                  beads were lost.         with barrier.  Try rear
                                                                                                                          barrier further back.
Did not lose plastic
beads.

Vortices formed in
front of barrier.
Try rear barrier fur-
ther back.

Move rear barrier fur-
ther back.
                                                                                                Occasional vortices      Try the anti-ventila-
                                                                                                formed,  occasional loss  tion board again.
                                                                                                of beads at 6" draft.

                                                                                                Some  of  the board were   Try coke box again.
                                                                                                lost.

                                                                                                Used  coke box arrange-   Use smaller angle  for
                                                                                                ment;  lots of turbu-     inclined plate; no
                                                                                                lence.                   plate.
IPM-8   18.8%    11      26        69        9      2.25   2.28  42/.67        69/9       16,17


IMP-9   18.8%    11      26        69        9      3.0    2.80  48/.S9        69/9       18,19


NOTE:  See Figure  B-l and Table B-2 for test configuration and dimensions.
                                                                                                 No ventilation;  no
                                                                                                 beads los t.
                         Try higher velocity.
                                                                                                 Did not lose beads;  79%   Try  higher velocity.
                                                                                                 reduction in velocity.

-------
                                                                              TABLE B-l

                                                         SUMMARY OF PERFORATED-PLATE BAFFLE TESTS  (Continued)
VD
U)
Plate
%
Test Open
No. #l/#2
IPM-10 18. 8/-

11 18.87-
Angle
of
Plate
#l/#2
12V-

12V-
Front
of
Plate
tl/#2
21/-

217-
Back
of
Plate
#l/#2
67/-

(,11-
Draft
of
Plate
#l/#2
12/-

12/-


Ref. Vel.
Vel. x=0
3.75

3.75


Vel.
x/fps
67/.90



Boom
Location/
Draft
117/6

105/6-11

No. of
Plate
Sets
1

1

Position
of
Plates
V

V


See
Figure
Calm in
of beads



Remai-ka
front of barrier
retained.
Barrier at 10" too deep,




; 80%

caus-
12  18.8/-      12V-    21/-   677-      12/-     3.75



13  18.8/-      12V-    217-   677-      12/-     3.75


14    46/18.8   16V13"  18/36  63/83     13/10    3.75


15  18.8/18.8   16°/18°  18/53  63/96     13/13    3.75



ISA   46/18.8   16V18"  18/53  63/96     13/13    3.75




16  18.8/18.8   157-12° 18/60  63/102    12/9     3.75



17    46/18.8   16°/19°  15/72  60/107    13/12    3175
                                                                                       93/6-11      1    V



                                                                                       81/6-11      1    V


                                                                                      105/12        2    V
                                                                             105/.14  120/10
                                                                             105/.28  120/10
                                                                                      115/6
                                                                                      117/10
              18  18.8/18.8   16V19"  15/72  60/107     13/12    3.75                 117/12

              19  18.8/18.8   16°/19°  15/60  60/95      13/12    3.75  3.37  102/.45  117/12
2    V
                                                                                                    2    V
2    V
                                                                                                    2    V
                                                                                      2    V

                                                                                      2    V
      ing too much back flow. Bar-
      rier at 6" eliminates most of
      the back flow.  Try moving
      closer.

      Caused increased flow upstream
      in front of boom.  Try moving
      barrier closer yet.

      Boom too close; lost most of
      beads.  Try too inclined plates.

20    Too much ventilation; lost
      beads; too much flow.

21    Reduce current flow; collected
      beads.  Try opening  forward
      plate.

      Too much turbulence  with 46%
      open area in Plate 1.  Try
      another plate orientation—
      invert Plate 2.

22    Would not hold beads in front
      of barrier.   Try inverting both
      plates.

23    Too much ventilation between
      sets of plates; would not
      collect beads.   Try  deeper
      draft barrier.

      Same problems.   Try  another way.

24    Same problems.   Try  another
      configuration.
          NOTE:  See  Figure  B-l and Table B-3 for test configuration and dimensions.

-------
                                                                     TABLE B-l

                                               SUMMARY OF PERFORATED-PLATE BAFFLE TESTS (Continued)
           Plate     Angle   Front  Back
             %        of      of     of
  Test      Open     Plate   Plate  Plate
   No.     fl/12     #l/#2   til 92  ti/«2
Draft
 of
Plate    Ref.  Vel.    Vel.
#i/#2    Vel.  x = 0   x/fps
  Boom     No. of  Position
Location/   Plate     of      See
  Draft     Sets    Plates   Figure
                                                                                                                             Remarks
     20    46/18.8   19°/20° 18/28  60/75   14.5/17.5  3.75                  102/10       2    V




     21  18.8/18.8   18°/13° 21/48  63/95     13/11    3.75  3.93            108/10       2    V



     22    46/18.8   18°/13° 21/48  63/95     13/11    3.75                  107/10       2    V


     22A   46/18.8   18°/13° 21/48  63/95     13/11    3.75                  117/10       2    V


     23  19.7/18.8   18°/13° 21/48  63/95     13/11    3.75                  117/10       2    V


     24  18.8/18.8   180/130 21/48  63/95     13/11    3.95                  116/11       2    V



     25  18.8/18.8   18°/13° 21/46  63/95     13/11    3.95                  116/11       2    V



     26  18.8/18.8   19°/16° 17/49  60/95     15/13    3.7                   117/11       2    V



     27  18.8/18.8   19°/16° 16/49  60/95     15/13    4.1                   117/11       2    V


     28  18.8/18.8   19°/16° 17/49  60/95     15/13    4.83         5.04     117/11       2    V



     29   18.8/18.8   19V16" 17/49  60/95     15/13    5.06         5.09     117/11       2    V
                                                           25,26   Causes water  to  fall; beads are
                                                                   lost  and  turbulence is severe:
                                                                   would likely  cause emulsions.
                                                                   Change configuration.

                                                            27      Antiventilation  board held in
                                                                   place eliminates most venti-
                                                                   lation.

                                                                   Barrier 10" deep causes too much
                                                                   current action in front of boom.

                                                                   Better condition with barrier
                                                                   further back; better with board.

                                                            28      Using board almost all beads
                                                                   were  caught.

                                                                   Lost  most of  the beads. Horizon-
                                                                   tal flow  control board was not
                                                                   used.

                                                                   Lost  most of  the beads.  Hori-
                                                                   zontal flow control board was
                                                                   not used.

                                                           29,30   With  a set of three boards
                                                                   rather than one, almost all of
                                                                   the beads were retained (95%).

                                                           29,30   With  this higher velocity, 90%
                                                                   of all beads were retained.

                                                                   All tests have 3 horizontal
                                                                   boards in place; 80% of beads
                                                                   were  retained.

                                                                   A slight  increase in velocity
                                                                   caused a 40%  loss of beads.
NOTES:   (a) Velocity  readings taken with an Ott Kempten Current Meter next to Ducted meter at reference point  six  feet  in  front of incline
            plate model.
         (b) See Figure B-l and Table B-3 for test configuration and dimensions.

-------
Ui
                                                                             TABLE B-l


                                                       SUMMARY OF PERFORATED-PLATE BAFFLE TESTS (Continued)


Test
No.
Plate
X
Open
#l/#2
Angle
of
Plate
#l/#2
Front
of
Plate
•l/»2
Back
of
Plate
#1/12
Draft
of
Plate
tun


Ref.
Vel.


Vel.
x=0

\
Vel.a)
x/fps

Boom
Location/
Draft

No. of
Plate
Sets

Position
of
Plates


See
Figure



Remarks
         IP»-30    48/18.8  20°/180  21/54  61/95  15/13  4.72         4.64    117/11       2     V


             31    25/18.8  20°/18°  21/54  61/95  15/13  4.74         4.79    117/11       2     V

             32  18.8/18.8  20°/18°  21/54  61/95  15/13  4.83         4.77    117/11       2     V

             33  18.8/18.8  20°/18°  21/54  61/95  15/13  4.6          4.77    117/11       2     V
31    Last most of the beads.   Horizontal
      flow control board was not used.


32    75% of the beads were retained.

      75% of the beads were retained.

      Approximately 80% of  all  beads were
      retained by model.  Thus  tests No.'s
      IPM-28 and 53 are the best.
         NOTES:  (a) Velocity readings  taken with  an Ott Kempten Current Meter next to Ducted meter at reference point six feet  in  front of  incline

                     plate model.
                 (b) See Figure B-l and Table  B-3  for  test  configuration and dimensions.

-------
                                                           Trailing        '
                                                  Boom     Plate
                     TESTS IPM-1A THROUGH  IPM-9
                               144"
                            PROFILE  VIEW

                     TESTS  IPM-10  THROUGH  IPM-33

FIGURE B-l  - SKETCH OF PERFORATED  PLATE BAFFLE TEST CONFIGURATIONS
             SEE TABLE B-l  FOR SUMMARIZED  RESULTS
                                96

-------
 Test
  No.
      Vel.
              X
                                   TABLE B-2


                       PERFORATED PLATE BAFFLE PRINCIPAL
                        DIMENSIONS TESTS IPM 1 TO IPM 9
                                            Plate
                                            Angle
                                                         % Open    Components
                                                          Area        Used
IPM 1A    2.2     39    69
                                    10
                                             18
                                                      46
    IB
2.25    39    69
                                10
                                             18
                                                          18.8
    1C    2.2     39    69
                                    10
                                             18
                                                      18.8
                                                                      ca
2A    2.2
                  39    69    69    10    10
                                                 18
                                                      18.8
2B    2.25    39    69    69    10    10     18°
                                                          18.8
      2.25    39    69    71    10    10
                                                 18
                                                      18.8
      2.25    39    69    84    10    10
                                                 18
                                                      18.8
      2.25    39    69    96    10
                                                 18
                                                      18.8
      2.25    39    69    69    10    10     18°
                                                          18.8
      2.25    39    69    79    10    10     18C
                                                          18.8
      2.25    26    69    69
                                                 11
                                                      18.8
      3.0     26    69    69
                                                 11
                                                      18.8
a)  Board was used
b)  Coke box was used
c)  Boom and trailing plate were not used
                                     97

-------
00
                                                        TABLE B-3

                                                 PERFORATED PLATE BAFFLE
                                                  PRINCIPAL DIMENSIONS
Test
No.
10
11
12
13
14
15
15A
16
17
18
19
20
21
Plate
Incli-
nations
V
V
V
V
V
V
V
V
V
V
V
V
V
TESTS IPM-10 TO IPM-33
Coordinates
(in.)1
21,0
21,0
21,0
21,0
18,0
18,0
18,0
18,0
15,13
15,13
15,13
18,14.5
21,0
X2, Y2
(in.)
57,10
67,10
67,10
67,10
63,13
63,13
63,13
63,12
60,0
60,0
60,0
60,0
63,13
X3, Y3
(in.)

-
-
-
36,0
53,0
53,0
60,9
72,0
72,0
60,0
28,17.5
48,0
(in.)
-
-
-
-
83,10
96,13
96,13
102,0
107,12
107,12
95,12
75,0
96,11
(Deg)
12
12
12
12
16
16
16
15
16
16
16
19
18
2*
(Deg)

-
-
-
13
18
18
12
19
19
19
20
13
X5
(in.)
117
105
93
81 i
105
120
120
115
117
117
117
102
108
(in.)
6-11
6-11
6-11
6-11
12
10
10
6
10
12
12
10
10
% Open Area
Plate 1
18.8
18.8
18.8
18.8
46.0
18.8
46.0
18.8
46.0
18.8
18,8
46.0
18.8
Plate 2
-
-
-
-
18.8
18.8
18.8
18.8
18.8
18.8
18,8
18.8
18.8
      *<(>  and 9 are measured from the water line to the plate for both cases  (planing  or  diving).

-------
                                                  TABLE B-3  (Continued)
vo
VO
Test
No.
22
22*
23
24
25
26
27
28
29
30
31
32
33
Plate
Incli-
nations
V
V
v
v
V
V
V
V
V
V
V
V
V
Coordinates
(in.)1
21,0
21.0
21,0
21,0
21,0
17,0
17,0
17,0
17,0
21,0
21,0
21,0
21,0
X2> Y2
(in.)
63,13
63,13
63,13
63,13
63,13
60,15
60,15
60,15
60,15
61,15
61,15
61,15
61,15
XV
"}» M
(in.)"
48,0
48,0
48,0
48,0
48,0
49,0
49,0
49,0
49,0
54,0
54,0
54,0
54,0
(in. )
95,11
95,11
95,11
95,11
95.11
95,13
95,13
95,13
95,13
95,13
95,13
95,13
95,13
1*
0>eg)
18
18
18
18
18
19
19
19
19
20
20
20
20
4>2*
(Deg)
13
13
13
13
13
16
16
16
16
18
18
18
18
X5
(in.)
107
117
117
116
116
117
117
117
117
116
117
117
117
(in.)
10
10
10
11
11
11
11
11
11
11
11
11
11
% Open
Plate 1
46.0
46.0

18.8
18.8
18.8
18.8
18.8
18.8
48.0
25.0
18.8
18.8
Area
Plate 2
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8
18.8

-------
     FIGURE B-2 - TEST SETUP, TOP VIEW
FIGURE B-3 - INCLINED PLATE  SETUP,  18.8%  OPEN
                     100

-------
      FIGURE B-4 - SIDE VIEW THROUGH TANK WINDOW
FIGURE B-5 - PERFORATED INCLINED PLATES WITH REAR BOOM
                          101

-------


FIGURE B-6 -  IPM-1A:  SIDE VIEW, 2.2 FPS, 46% OPEN
         1 •*i»>»
         J <*tvK*
  FIGURE B-7 - IPM-1A:  TOP VIEW, 46% OPEN, 2.2  FPS
                    102

-------
      FIGURE B-8 -  IPM-1B:  TOP VIEW, 18.8% CLOSED, 2.2 FPS
FIGURE B-9 - IPM-1B:   SIDE VIEW,  18.8% OPEN,  2.2  FPS,  VENTILATION
                               103

-------

FIGURE B-10 - IPM-1C:   ANTIVENTILATION BOARD ON TOP OF PLATES
         FIGURE B-ll  - IPM-1C:   18.8% OPEN,  2.2 FPS
                            104

-------
           -V
      ,


FIGURE B-12 - IPM-3:   18.8% OPEN,  2.25  FPS,  BOOM  IN  PLACE


FIGURE B-13 - IPM-4, 18.8% OPEN, 2.25 FPS, BOOM AT X = 84
                           105

-------
              y-
              \
               •m
               *
FIGURE B-14 - IPM-7:  COKE  BOX ARRANGEMENT, NOTICE TURBULENCE;
                  18.8% OPEN, 2.25 FPS
                                      •
                                     ,
                                            'r-.\-

                                       •:..•'•':
                                   ''  ^ '•' •'
                             ^^*4**1  :--:: *j
                             **S%2*Mi
                                          . f.i ••. tn
        FIGURE B-15 -  IPM-7:  PHOTO OF COKE BOX ARRANGEMENT
                            106

-------
   FIGURE B-16 - IPM-8:  SIDE VIEW AT 2.25 FPS WITH 18.8% OPEN AREA
              i.  '

            -'-
            *• *  '
FIGURE B-17 - IPM-8:   18.8% OPEN AREA,  2.25 FPS,  BOOM AT END OF PLATE;

                      NOTICE QUIET SURFACE IN FRONT OF THE BOOM
                                 107

-------
FIGURE B-18 - IPM-9:   3.0 FPS,  18.8%  CLOSE,  SURFACE OF WATER IS STILL
     FIGURE B-19 - IPM-9:   SIDE VIEW,  18.8% OPEN  AREA  AT  3.0  FPS
                                  108

-------
                 >*^  -
                ••///.
                                   V S
FIGURE B-20 -  SET-UP  FOR  IPM-14, NO CURRENT
    FIGURE B-21  -  TEST  IPM-15,  3.75 FPS
                    109

-------
        FIGURE B-22 - TEST IPM-16, 3.75 FPS
              .»•
FIGURE B-23 - TEST IPM-17, 3.75 FPS, BOOM 10" DEEP
                        110

-------
FIGURE B-24 - TEST IMP-19, 3.75 FPS,  BOTH PLATES  18.8%  OPEN

             FIGURE B-25  -  TEST IPM-20,  3.75 FPS
                             111

-------
       FIGURE B-26 - TEST IPM-20,  3.75 FPS
FIGURE B-27 - TEST IPM-21, HAND HOLDING BOARD ON
              UPSTREAM SET OF PLATES, 3.75 FPS
                       112

-------
FIGURE B-28 - TEST IPM-23 FPS, HAND-HOLDING BOARD
                        113

-------
FIGURE B-29 - TESTS 26 AND 27,  BOARDS IN PLACE
   FIGURE B-30 - TESTS 26 and 27, SIDE VIEW
                      114

-------

                                      i
FIGURE B-31 - TEST IPM-30.   PLATE 1 IS 48% OPEN
              AND PLATE 2 IS 18.8% OPEN;  THE
              VELOCITY IS 4.7 FPS
FIGURE B-32 - TEST IPM-31, PLATE 1 IS 25% OPEN
              AND PLATE 2 IS 18.8% OPEN; THE
              FREE STREAM VELOCITY IS 4.7 FPS
                      115

-------
                    IMPERVIOUS  BOARDS TO  PREVENT  VENTILATION
FLOW
                       '18.8% OPEN AREA (TYP)
                PROFILE
                      SCALE  l"= 16"
                                                                 OPEN (TYP)
                                                   DETAIL OF  HOLE PATTERNS
           FIGURE B-33 - OPTIMUM INCLINED PLATE BAFFLE BOOM ARRANGEMENT
                     BASED ON FULL SCALE TESTS IN CURRENT TANK

-------
                                                    TOP OF  SIDEWALL
                                                                         AFT INCLINED PLATE
                                                                            HN.T.S.)
                                                                                    AFT  BARRIER
      -6'
        I
             -4'
             11
                 -2'
-X
                                                                           L02 763 475 J0t7 .17 .085 .085
                                                                                1.61 •

                                                                               1.61  186 L52 L59 L86  2.29
                                                                                                      5L
h-
-j
 4.61
   •
6"_

 546
12" !_


18? _


24'_
5.03   5.12    4.74  5.25   4.83
 *     •  —. •    •     •

           f
4.95   5.43   5.43  5.42


    FLOW
                       5.42
    SCALES:
      x: i"=r-o"
                                                                                           4.16
                                                            FWD INCLINED PLATE
                                                            (4 N.T.S.)
                  FIGURE B-34  -
                          POINT VELOCITIES FOR A ?. PLANE THROUGH  INCLINED PLATE PROFILE.
                          FREE-STREAM VELOCITY IS 4.8 FPS (2.8 KNOTS).  VELOCITIES  SHOWN
                          ARE IN FPS.

-------
                                                            12'-0"  SIDEWALL (TYP)
CO
                                  -X
                             +X
       f
1'         1
      4.61    5.03    5.12   4.74   5.25
               FLOW
                 •••••Mi
       SCALES: x. r-a'-b"
                              7
                                           TOP OF FWD PLATE
                                           AT  W.L.


5.09


4.83
•



4.66
0

r
i
4.15
r
3.98
— •_


4.24
f
2' 4' /
1 1 /
/
•
5.17 4.75 5.00 3.56 1.70
* *! * * *
4.75 3B2 425 3.73 178
• • • • •
i
i
4.92 370 4.66 3.22 2.03
	 1 	
6'
1


1.70

1.02
•


.49
•

81 \ 10'
1 \ 1
\
| *
44 .61 .85 .34 .424 .25
i
.76 48 .017 .017 .085 .085
• • • f • •-
i
I
.170 .09 .0 .017 0 .085
• • • f • •
	 J 	
-9



• 0



-4.Q
7
                                                        BOT OF AFT PLATE
                                                        BELOW W.L.
                  FIGURE B-35 - POINT VELOCITIES FOR A HORIZONTAL PLANE 3" BELOW THE WATER'S SURFACE.
                               THE FREE-STREAM VELOCITY IS 4.8  FPS (2,8 KNOTS) IN FRONT  OF THE
                               INCLINED PLATE BOOM PROFILE.

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                                  APPENDIX C

                     SUMMARY OF PERFORATED PLATE TOW TESTS

INTRODUCTION

     These tests were run  to determine the specific boom configuration that
gives the greatest oil retention rate at a 2-1/2 knot tow speed without waves.
The boom section shown in  Figure 27 in the body to this report is to be modi-
fied in an effort to enhance its oil retention capacity.  Previous tests were
run with PVC beads, so these are the first ones using oil.  Results are given
in Table 1 of the main report.

     The Shell wave/tow  tank shown in Figure 33 was used for the tow and tests.
The initial boom position  and the test section are indicated.  Figure C-l
shows the test rigging used to apply and contain oil.  The test oil for this
phase of tests is a Navy Distillate oil, similar to No. 2 Fuel Oil in physical
properties.

TEST PROCEDURE

     The procedure for each tow run is generally as follows:

     1.  Check wave/tow  tank for accumulated oil from previous runs.  If oil
         is present, remove it or isolate it with a boom so that oil lost from
         the test to be  run can be separated.

     2.  Place the boom  section and associated apparatus in the aft slip of
         the tow tank.   Attach cables and hoses.

     3.  (a)  If the test  to be run is a "constant volume" one, slowly pour
              the oil into the rear area of the boom using a tear-away barrier
              forward to restrain the oil before the tow run.

         (b)  If the test  is a "constant flow rate" one, start the oil flow
              from the storage tank into a return sump by turning on the pump
              switch.  After flow is initiated and after the boom reaches the
              beginning  of the 100' test section, activate a 3-way valve to
              direct the flow into the hose that feeds oil in front of the
              boom during  the tow run5?

     4.  Start the electric powered winch to initiate the tow run.  Control
         the speed to affect all of the acceleration before the start of the
* The flow has been previously calibrated by timing the oil accumulation  in  a
  5-gallon drum.

                                      119

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                                     Pulling on back line raises
                                     curtain during test run.
                                     Releasing rope
                                     closes curtain. \       XX
Flexible Plastic Joint
to Seal Against
Oil Leaks
                                                           oom
                                                         Section
                                                       (Test  Item)
                                              Oil  Containment Area
                                                and Drop Curtain
                                                 (Test Fixture)
                                    Hinge
           Oil  Supply
             Hose
      Tow  Line

FIGURE C-l - TEST RIGGING FOR APPLYING AND  CONTAINING  THE  OIL
                              120

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    test section is reached.  Hold the winch speed constant while the
    boom moves through the 100' test section.

5.  If the run is a constant volume test, raise the curtain when the
    speed is high enough to force the oil to the rear barrier of the boom.
    If the run is a constant flow rate one, raise the curtain any time
    before the 3-way valve is turned to apply the oil.

6.  After the boom passes the end point of the test section:

         Constant Flow Rate Test.  Divert the oil flow back to the sump
    using the 3-way valve.  After decreasing the winch speed, release
    the aft rope to lower the oil confining curtain.

         Constant Volume Test.  Same as for Constant Flow Rate Test
    except omit the 3-way valve change.

7.  Check to see that oil is not lost under the forward curtain during
    the deceleration phase.  If oil is lost in front, use water hoses to
    separate this loss from the loss under the boom during the test run.

8.  Remove the oil  lost under  the skimmer from the tank and measure it.
    Remove the oil  remaining in the skimmer and measure it.  Notes;
     (a) take care not to emulsify oil during pickup;  (b) allow adequate
    time  for gravity settling  of oil in  container prior to measuring the
    volumes of oil.
                                      121

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                                  APPENDIX D

                    THREE-DIMENSIONAL TOW TESTS - HOUSTON

     At the conclusion of the two-dimensional test program three-dimensional
(diversion) tests were also conducted at Houston.  Five four-foot-wide boom
segments were joined side-by-side to form a 20-foot-long high-current boom.
The boom was attached to the towing bridge with cables and a trailing boom was
attached to the downstream end of the high-current boom to separate the oil
successfully diverted during the run from that lost under (or over) the high
current boom.

     Oil was applied to the water in front of the advancing boom using a wide
pipe manifold attached to the bridge.  Equally spaced holes in the pipe allow
oil to flow onto a flexible plastic curtain.  The overlaping flow plumes run
down the curtain onto the water creating an approximately uniform thickness
oil lens about six feet wide.  Normally the manifold was located to allow the
oil to approach the boom at mid-length.  Oil was applied to the water at a
constant flow rate for a tow distance of 75 feet.

     Figure D-l shows a sketch of the test set-up in the wave tank.

     The tow test conditions and results are contained in Table D-l.  Notice
that all of the oil diversion percentages are above 90%.  By comparing the
results of Table D-l with those for the OHMSETT tests (Table 5 in the main
body of this report), one finds that the results (excluding the denser Navy
Special oil tests) are similar except for tow runs above 2.5 knots.  At the
higher speeds we feel that the Houston tank is too short (for towing wide
devices) and that the oil losses under the high-current boom would be created
in a longer tank.

     We conclude that the OHMSETT diversion test results are more reliable
than the results from this short tank.  Consequently these results were not
relied upon in quantitatively assessing the performance of the high-current
boom in diversion.
                                      122

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N3
                                                                              20'  High-Current Boom
                                                                                                 Wave Absorber
              Tow Winch
Oil Storage
                                                                                          Trailing  Boom
                              FIGURE D-l  -  BOOM TEST SET-UP  IN  HOUSTON  WAVE/TOW TANK

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                  TABLE D-l




DIVERSION TESTS OF THE EPA HIGH CURRENT BOOM




                HOUSTON TANK


Run- Angle
1-15°
1-30°
1-45°
1-60°
2-15°
2-30°
2-45°
2-60°
3-60°
4-15°
4-45°
5-45og)
6-45oS)
7_45°g)
8-45°g)
9-45°
10-45°
11-45°
12-45°
13-45°
NOTES: a)
b)
c)

d)
e)

f)
8)

h)
i)
j)
Steepness Equiv. Slick
Wave Height Ratio Thickness
Knots (ft) (H/L) (mm)
2.4 — — 2.3
2.4 — — 2.5
2.5 — — 2.2
2.5 — -- 2.2
3.0 — — 1.9
2.9 — — 1.8
3.0 — — 1.9
3.0 — — 1.8
3.6 — — 1.6
2.4 0.5 0.05 2.2
2.4 0.5 0.05 2.2
2.5
2.6 0.5 0.05 2.0
2.5 1.0 0.05 2.0
2.4 — — 2.4
2.5 1.0 0.05 1.5
2.5 1.0 0.05 1.5
2.5 0.5 0.05 1.3
2.5 — — 1.3
2.5 — — 1.6
Five four-ft wide boom sections were used.
The transverse direction is 0°, the tow direction is 90
Oil flow from the nozzle was begun at the start of the
tow line.
Navy Distillate was used in the tests (6 cp at 77°F).

Percent
Oil Loss
2.6
1.3
0.8
3.0
2.0
1.1
2.6
1.3
0.9
1.5
2.8
—
9.6
9.1
3.5
4.3h
9.61
6.01
4.41
6.4^

O
*
75-ft


Percent oil loss based on comparison of the total volume lost
with the total volume applied.
Center of nozzle in line with center of boom, except as
Center of nozzle moved from center of boom 4-ft toward
edge of boom.
Oil applied at starting point.
Oil applied 10-ft before starting point.
Oil applied 25-ft before starting point.

noted.
leading




                     124

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                                   APPENDIX JS

                              OHMSETT TEST FACILITY

      The  U.S.  Environmental Protection Agency  is operating on Oil and Hazar-
 dous  Materials Simulated Environmental Test Tank (OHMSETT) located in Leonardo,
 New Jersey.   This facility shown in Figure E-l provides an environmentally safe
 place to  conduct  testing and development  of devices and techniques for the
 control of  oil and hazardous materials spilled in inland and coastal waters.

      The  primary  feature of the  facility  is a pile-supported, concrete tank
 with  a water  surface 667 feet long by 65  feet wide and with a water depth of
 8  feet.   The  tank can be filled  with fresh or  salt water.  The tank is spanned
 by a  towing bridge which can tow loads up to 34,000 Ibs. at speeds to six knots
 for a duration of 45 seconds.  Slower speeds yield longer test runs.  The
 towing bridge is  equipped to lay oil on the surface of the water several feet
 ahead of  the  device being tested,  such that reproducible thicknesses and widths
 of oil slicks can be achieved with minimum interference by wind.

      The  principal systems of the tank are a wave generator and beach, a bub-
 bler  system,  and  a filter system.   The wave generator and absorber beach have
 capabilities  of producing non-reflecting  waves to two feet high and 80 feet
 long,  as  well as  a series of reflecting,  complex waves which simulate the
 complex water surface of a harbor or estuary.  The water is clarified by recir-
 culation  through  a diatomaceous  earth filter system to permit underwater
 photography and video imagery, and to remove the few ppm of hydrocarbons that
 remain after  a test.   A bubbler  system which prevents oil from reaching the
 tank  walls, the beach,  or the wave generator.  This system is designed to
 speed cleanup  between test runs,  since a  clean tank surface is essential to
 reproducible  oil  spill conditions.   The towing bridge has a built-in skimming
 board which,  in conjunction with the bubbler system, can move oil on to the
 farthest  end  of the tank from the generator for cleanup and recycling.

      When the  tank must be emptied for maintenance purposes, the entire water
 volume (2.6 million gallons)  is  filtered  and treated until it meets all appli-
 cable state and federal water quality standards before being discharged.

      Tests  at  the facility are supported  from a 7,000 square foot building
 adjacent  to the tank.   This building houses offices, a quality control labora-
 tory  (which is  very important since test  oils and tank water are both recycled)
 a  small machine shop,  and an equipment preparation area.

     OHMSETT is a government  owned,  contractor operated facility.  The operat-
 ing contractor, Mason and Hanger-Silas Mason, Co. Inc., provides a staff of
eleven multidisciplinary personnel.   The  U.S. Environmental Protection Agency
provides  project  guidance and  expertise in the area of spill control  technology.
                                       125

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I
1
                              FIGURE E-l  - THE EPA WAVE/TOW TANK CALLED OHMSETT

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                        APPENDIX F

on '
Type
Sun 75
Sun 75
Sun 75
Sun 75
Sun 75
Sun 75
Sun 75
Sun 75
12 Fuel
#2 Fuel
M? Fuel

Applied or
Recovered
Test #
Applied
Tests 1*?
Applied
Test 3
Recovered
Test 4
Recovered
Test 6
Recovered
Test 5
Applied
Tests 7&8
Recovered
Test 7
Recovered
Test 8
Applied
Test 9&10
Recovered
Test 9
Rprm/pred
APPLIED AND RECOVERED OIL PROPERTIES
OHMSETT TESTS
Oil Interfacial
Oil Sp. Surface Tension
Temp Gr. Tension Oil /Sea
V(cs) (°F) (g/cc) (dynes/cm) Water
267 120 0.875 30.1 9.1
863.3 88 0.890 30.8 13.8
68
74
75
578.5 110 0.886 31.6 9.6
73
73 -
7.1 80 0.847 28.8 13.6
- - - -
. - - -

Percent
Water
0.8
9.0
25.0
21.0
25.0
8.0
30.0
20.0
-
3.0
8.5
Test 10
                            127

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         SELECTED  PHOTOGRAPHS, OHMSETT TESTS
FIGURE F-l  - TEST 2.   BOOM AT 45° USING SUN 75 OIL,
             TOW VELOCITY 3.0 KNOTS, NO WAVES
                                     ,
 FIGURE  F-2  -  TEST  5.   BOOM  AT  45°  USING  SUN  75  OIL,
              TOW VELOCITY 3.25 KNOTS,  WAVES  6"  HIGH
              AND 3 SECOND PERIOD
                         128

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           SELECTED PHOTOGRAPHS, OHMSETT TESTS
  FIGURE F-3 - TEST 6.   BOOM AT 45° USING SUN 75 OIL,
               TOW VELOCITY 3.0 KNOTS, WAVES 8" HIGH
               AND 2 SECOND PERIOD
FIGURE F-4 - TEST 9.   BOOM AT 45° USING NO. 2 FUEL OIL,
             TOW VELOCITY 3.0 KNOTS AND NO WAVES
                           129

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           SELECTED PHOTOGRAPHS,  OHMSETT TESTS
FIGURE F-5 - TEST 10.  BOOM AT 45° USING NO.  2 FUEL OIL,
             TOW VELOCITY 3.0 KNOTS, WAVES 8" HIGH
             AND 2 SECOND PERIOD
                           130

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                              APPENDIX G
                 ENGLISH  - METRIC CONVERSION  TABLE
Multiply

feet
feet/second
feet/second2
gallons
galions/minute
inches
knots
pounds
pounds/cubic  foot
   bjr

  0.305
  0.305
 30.480
  3.785
  0.063
  2.540
  0.515
453.600
  0.016
 To Obtain

meters
meters/second
centimeters/second2
liters
liters/second
centimeters
meters/second
grams
grams/cubic centimeter
                                      131

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                                    TECHNICAL REPORT DATA
                             /I'lcasc read Instructions on the reverse before com/1'1
 1  RtPGfl I NO.
  EPA-600/2-76-263
                               2.
                                                             3. RECIPIENT'S ACCESSION'NO.
4. TITLfc AND SUBTITLE

   A RIGID,  PERFORATED PLATE  OIL BOOM FOR HIGH CURRENTS
                                                             5. REPORT DATE
                                                               December 1976  issuing date
                                                             6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)

    Ray  R.  Ayers
                                                             8. PERFORMING ORGANIZATION REPORT NO.
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
    Shell  Development Company
    Westhollow Research Center
    P. 0.  Box 1380
    Houston,  Texas  77001
                                                            10. PROGRAM ELEMENT NO.
                                                               1BB610
                                                            11. CONTRACT/GRANT NO.

                                                              68-03-0331
 12. SPONSORING AGENCY NAME AND ADDRESS
    Industrial Environmental Research Laboratory-Gin.,  OH
    Office  of Research and Development
    U.  S. Environmental Protection Agency
    Cincinnati,  Ohio  45268
                                                            13. TYPE OF REPORT AND PERIOD COVERED
                                                              Final: July 1978-May 1976
                                                            14. SPONSORING AGENCY CODE
                                                                EPA/600/12
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT
        A  boom capable of diverting oil spills toward shore in a 3-knot (1.5 m/s)  river
   or tidal  current has been developed.  Loss of No. 2  and  No.  4 Fuel Oil at this
   velocity  is typically less  than 15 percent when the  angle of the boom is 45 degrees
   to the  shoreline.  In contrast,  conventional booms lose  this amount at only 1 knot
   (0.5 m/s).
        Good performance at high  currents is achieved by  placing a baffle upstream of
   a conventional flat plate boom.   The baffle, an inclined, perforated plate, is  used
   to create a flow-sheltered  region where the oil layer  thickens.  A continuation of
   the inclined plate baffle forms the "floor" of the sheltered region to control  the
   flow rate of exiting water.  Horizontal plates immediately behind the baffle reduce
   water down-flow.
        The  boom is made up of  8-foot (2.4 m) long, rigid sections similar in plan view
   to a floating dock module.   The length of the boom depends upon the number of modules
   pinned  together side by side.   Floating suction or sorbent rope collection devices may
   be used to  remove accumulated  oil from the flow sheltered region and increase "capa-
   city" .
        Drawings are provided  to  permit construction by others.	
                                 KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
      Water Pollution
                                               b.lDENTIFIERS/OPEN ENDED TERMS
                                                                          c. COSATI Field/Group
                                                 Oil Spills,
                                                     Booms,
                                                     Barriers
  13B
 3. DISTRIBUTION STATEMENT

       Release to Public
                                               19. SECURITY CLASS (This Report)
                                                     Unclassified
21. NO. OF PAGES
     142
                                               20. SECURITY CLASS (This page)
                                                     Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
                                             132
                                                     U.S. GOVERNMENT PRINTING OFFICE: 1977-757-056/5'i69 Region No. 5-11

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