6OO281141
                               "O CONTROL OIL SPILLS
                          bx
                   Michael K. Breslin
          Mason & Kanger-SiJas Mason Co., Inc.
              Leonardo, New jersey 07737
                Contract No. 68-03-26^2
                    Project Officer

                    3ohn S. Farlow
        Oil and Hazardous Materials Spills Branch
      Municipal Environmental Research Laboratory
               Edison, New Jersey  08817
MUNICIPAL 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  Municipal Environmental  Research
Laboratory, 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 irade names or
commercial products constitute endorsement or recommendation for use.

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                                   FOREWORD
       The U.S. Environmental Protection Agency was created because of Increasing
public and  government  concern about  the dangers  of  pollution to  the  health  and
welfare of the  American people. Noxious air, foul water, and spoiled land are tragic
testimonies to  the deterioration of our natural environment.  The compjexity of that
environment and the interplay of its components require a concentrated and integrated
attack on the problem.

       Research and development is  that  necessary first step in problem  solution; it
involves  defining the problem, measuring its impact, and searching for solutions.   The
Municipal Environmental Research  Laboratory develops new and improved technology
and systems to prevent, treat, and manage wastewater and solid and hazardous waste
pollutant discharges from municipal and community sources,  to  preserve and treat
public drinking water supplies, and to minimize the adverse economic, social, health,
and aesthetic effects  of  pollution.   This publication is  one of the products of that
research and provides  a  most vital communications link between  the researcher  and
the user  community.

       This report  describes a tool  developed at the EPA Oil and Hazardous Materials
Simulated Environmental Test Tank (OHMSETT) facility to control oil slick movement.
A high-pressure, coherent water stream was directed vertically into a body of water,
causing a surface current that controlled movement of an oil slick. Several tests were
performed to determine optimum effectiveness.  Results of these tests as well as a
theoretical analysis of the currents produced by the water jets are given.  This report
will be of interest to all those interested in controlling oil spills in inland and coastal
waters.  Further information  may  be obtained through the Resource  Extraction  and
Handling Division, Oil and Hazardous  Materials Spills Branch, Edison, New Jersey.
                                 Francis T. Mayo
                                    Director
                   Municipal Environmental Research Laboratory
                                   Cincinnati
                                         in

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                                   ABSTRACT
       The ability of coherent water streams to induce a surface current in a body of
water  and thus control a floating oil slick was examined in a number of test programs
conducted  at  the  U.S.  Environmental Protection Agency (EPA) Oil  and Hazardous
Materials Simulated Environmental Test Tank (OHMSETT).  The objective of the tests
was to determine whether coherent water streams could serve  as an  alternative to
fabric  booms and water sprays in concentrating, diverting, and containing oil slicks.

       The water jets were constructed from standard commercial  pipe  fittings  and
supplied  with water  from off-the-shelf centrifugal water pumps.  They were mounted
on the main towing bridge, they were built into small  floats which were angled across
the direction of tow  and  extended from the  bows  of  a simulated oil skimming
catamaran.  Currents of up to 6 kt were  induced by  towing the water jets from  the
main  bridge  down  the  test tank.  Regular  waves  and  harbor  chop or  confused  sea
conditions were developed by the tank's wave generator.

       The tests showed  that coherent jets could induce a significant surface current
and move an oil slick with little oil entrainment.  The  non-breaking waves produced by
the OHMSETT wave generator did not greatly affect performance except where  the
jet nozzles were cantilevered off the front of  the  catamaran and  the pitch of  the
vessel  caused significant changes in the height and attitude of the jet outlet.  The best
position for a fixed water jet of the sizes  and at  the pressures tested was  determined
to be vertically directed at the surface of the water with the outlet 0.4 to 1.0 m above
the surface.  These tests showed  that the vertical forced  component  of  a  coherent
water  stream was as useful, if not more so, as the horizontal forced component.  The
performance  of  a water jet powered by  a  30  kw electric motor/centrifugal pump
system exceeded that of an air jet of compressed air (210  kPa) extended  0.6 m below
the surface and supplied by a 50 kw gasoline-driven air compressor.

       This report was submitted in fulfillment of Contract No.  68-03-2642 by Mason
& Hanger-Silas Mason Co., Inc., Leonardo, New  Jersey, under the sponsorship of  the
U.S.    Environmental Protection  Agency.  This  report covers the following  six  test
periods:  August  28 to September 1, 1978; October 30 to November 11, 1978; May 21 to
3une 1, 1979; July  2 to  July 7, 1979; July 26 to July 27,  1979; and September 10 to
September 14, 1979, when the work was completed.
                                       IV

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                                   CONTENTS
                                                                               HI
                                                                               IV
                                                                               vi
                                                                              viii
                                                                               ix
                                                                                x
                                                                               xi
       1      Introduction	      1
       2      Explanation  and Basic Uses of Water 3ets to Control Oil Slicks ...      3
                   Introduction	      3
                   Conclusions	     12
                   Recommendations	     13
                   Test Description	     13
                   Test Procedures	     16
                   Discussion of Results	     23
       3      Water jets Mounted on a Moving Oil Skimmer	     47
                   Introduction	     47
                   Conclusions	     47
                   Recommendations	     49
                   Test Description	     50
                   Discussion of Results	     66
       4      Water 3ets Mounted on Individual Floats	     81
                   Introduction	     81
                   Conclusions	     83
                   Recommendations	     83
                   Test Description	     83
                   Discussion of Results	     89

References	     92
Appendices

       A.     OHMSETT Description 	   93
   '    B.     OHMSETT Oil Properties	     95

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                                LIST OF FIGURES
                                                                             Pae
        _ ^ T  .*   ~   .  '    L  .                2oCe „,..„..	      b
3      r\Ft Ln K-i^i v« d ic;T v .- ^ \K ul ea t j i < 161 '- o ~)>6  ^CU^'-HCC Oj, 3 St 8.1} OHcir V W3 16 T
             jet	1	      7
4      Static-nary water jet—side view	      9
5      Stationary water jet—xop view	     1C
fc      Moving water jet exhibiting characteristic wave train .................     11
7      Test set up for oil slick convergence tests		     14
8      Section view of convergence test set up	     15
9      Test set up for a single water jet test (slick parting tests)	     17
10     Water jet nozzle mounted on the main bridge	     18
11     M.G. 3ohnson  holding an OHMSETT oil slick sighter	     19
12     Effect of tow speed on oil slick movement (slick convergence tests)	     32
13     Effect of tow speed on oil slick movement (slick parting tests)	     33
14     Water jet performance in calm water and waves (slick convergence
             tests)	     35
15     Water jet performance in calm water and waves (slick parting tests) ....     36
16     Effect of number of water jets on oil slick movement (slick conver-
             gence tests)	     37
17     Effect of water jet pressure on oil slick movement (slick convergence
             tests)	     38
18     Effect of water jet pressure on oil slick movement (slick parting
             tests)	     39
19     Effect of water jet pressure and slick thickness on oil slick movement
             (slick convergence tests)	     40
20     Effect of slick thickness on oil slick movement (slick  parting tests)	     41
21     Effect of nozzle diameter on oil slick movement (slick parting tests) ....     42
22     Effect of water jet nozzle height on oil slick movement (slick parting
             tests)	     44
23     OHMSETT water jet nomograph used for Converging a 1 mm slick
             at 4 knots	     45
24     Comparison of water  jet performance to that of a compressed air
             source  (slick parting tests)  	     46
25     USCG ZRV skimmer using water jets to sweep oil  	     48
26     First generation water jet booms on the OHMSETT catamaran
             during  a tow test	     51
27     Second generation water jets mounted on the OHMSETT catamaran	     52
28     Details of second generation water jets	     53
29     Test set  up for oil skimmer/water jet tests	     54
30     Test set  up for stationary tests—pivoting a water jet  boom  	     55
                                       VI

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31    Underwater sequence of a water jet parting an oil slick	    56
32    Performance of a 1.25 err JD water jet at 4 knots In caJm water (slick
             convergence tests) ,	    70
33    An inwardly-directed nozzle on a single water jet boom mounted on
             the OHMSETT catamaran	    71
34    Performance of a 1.6 cm ID water  jet at 4 knots and 6 knots
             operating in -calm water (slick convergence tests)	    72
35    Performance of a 2.7 cm ID water  jet at 4 knots on a 7-meter and
             12-meter boom (slick convergence tests)	    73
36    Performance of a 2.7 cm ID water  jet a: 4 knots and 6 knots
             operating on a 12-meter  boom (slick convergence tests)	    74
37    Performance of a 2.]  err- iD wa:er  let at 4 knots (slick
             convei-£ence tests)	    75
38    Performance of a 2.1  cm ID water  jet at 6 knots operating
             on a 7-meter boom in calm  water (slick convergence tests)	    76
39    Water jet angled forward and inward during a calm water test	    77
40    Water jet ang'ec forward and inward during a wave les:	    7£
41    Tanoern water jets during a tow test	    SC
42    Isometric drawing of a water jet float	    82
43    Test set up for water  jet float program	    84
44    Water jet floats under tow diverting an oil slick	    85
45    Water jet float with gasoline pump	    87
46    Proposed water jet float/skimmer test set up	    90
                                       vit

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                             •   LIST OF TABLES


Nurr-ber                                                                     Page
                   :K Converger.ee Tests	    20
2     V.cirix for Siick Divergence Tests	    21
3     Test Matrix for Water jet Height Effects  	    22
4     Slick Convergence Test  Results	    2^
5     Slick Divergence Test Results	    29
6     Water jet Height Effects Test results	    31
7     Water jet/Oil Skimmer  Feasibility Test iv'atrix	    62
8     U.S. Coast Guard Skimmer/Water Jet Test Matrix (Stationary
            Tests)	    64
9     U.S. Coast Guard Skimmer/Water Jet Test Matrix (Tow Tests)  	    65
10    Water Jet/Skimmer Test Results	  .  67
11    Water Jet Float Test Matrix	    88
                                       VIII

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                        ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS

crru         --centimeter
cm          --squared centimeter
e.g.          --for example
EPA         --Environmental Protection Agency
deg          --degrees
fwd          --forward
HC          --harbor chop
ht           --height
i.e.          --that is
ID           --inside diameter
IND          --indeterrninant
kg           --kilogram
kPa          --kilopascals
kw          --kilowatts
kts          —knots
m           --meter
mm          --millimeter
no.          —number
Poly         --polypropylene
OHMSETT    --Oil and Hazardous Materials Simulated Environmental Test Tank
press         --pressure
sec          --seconds
thk          —thickness
u/w          --underwater
US          —United States
ZRV         --Zero Relative Velocity

SYMBOLS

10/20        --Descriptor of water jet nozzle orientation.  The first number is the
             angle, in degrees,  which the nozzle was  tilted from  the vertical in
             toward  the  centerline of the oil skimmer or catamaran^  The  second
             number is the angle, in degrees which the nozzle was  tilted from the
             vertical forward in order to shoot the stream  of water "upstream" of the
             system.

%           --percent
                                       IX

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                        METRIC CONVERSION FACTORS
METRIC TO ENGLISH

To convert from

Celsius
joule
joule
kilogram
meter
meter
meter 2
meter 2
meter 3
meter 3
meter/second
meter/second
meters/second
meters/second
meters/second
newton
watt

ENGLISH TO METRIC

centistoke
degree Fahrenheit
erg
foot
foot2
foot/minute
footS/minute
foot-pound-force
gallon (U.S. liquid)
gallon (U.S. liquid)/minute
horsepower (550 ft Ibf/s)
inch
inch 2
knot (international)
liter
pound force (Ibf avoir)
pound-mass (Ibm avoir)
psi
              TO

degree Fahrenheit
erg
foot-pound-force
pound-mass  (Ibm avoir)
foot
inch
foot2
inch2
gallon (U.S.  liquid)
liter
foot/minute
knot
centistoke
footS/minute
gallon (U.S.  liquid)/minute
pound-force (Ibf avoir)
horsepower (550 ft Ibf/s)
meter 2/second
Celsius
joule
meter
meter2
meter/second
meters/second
joule
meterS
meter S/second
watt
meter
meter2
meter/second
rrieterS
newton
kilogram
pascals
     Multiply by

tc = (tF-32)/l.S
1.000 E+Q7
7.374 E-Oi
2,205 E+00
3,281  E+00
3.937 E+01
1.076 E+01
1.549 E+03
2.642 E+02
1.000 E+03
1.969 E+02
1.944 E+00
1.000 E+06
2.119 E+03
1.587 E+04
2.248 E-01
1.341  E-03
l.OOOE-06
tc = (tp-32)/1.8
1.000 E-07
3.048 E-01
9.290 £-02
5.080 E-03
4.719 E-04
1.356 E+00
3.785 E-03
6.309 E-05
7.457 E+02
2.540 E-02
6.452 E-04
5.144 E-01
1.000 E-03
4.448 E+00
4.535 E-01
6.894 E+03

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                             ACKNOWLEDGMENTS
      The  work of M.G.  Johnson of Mason  & Hanger-Silas Mason  Co.,  Inc.,  in the
development  of the water  jets and during the  test programs described in this  report
contributed & great deal to  the success of the  U.S. EPA water jet program.

      Dr. R.I. Hires, Dr. 3.P. BresJin and Mr.  D.T. Valentine are gratefully acknow-
ledged for their work in developing the first theoretical analyses of water jets.^'6,7

      Mr. 3.S. Farlow, EPA Project Officer for OHMSETT, is gratefully acknowledged
for his technical guidance throughout the test  program.
                                       XI

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                                   SECTION  J

                                INTRODUCTION
       Two factors that cause  the  cost  of  oil spill cleanup  to  soar  are labor and
expensive equipment Inadequacy or failure. This report describes a method developed
by the U.S. Environmental Protection Agency (EPA)  that could reduce both of  those
costs:  The use of a downward vertical coherent stream of water delivered from a high
pressure source onto the body of water containing the oil spill.  The result  is a.  surface
current away from  the  point of impact.  The surface current induced can effectively
control the movement of the oil slick.  The device has been named  the water jet.

       The air-entraining properties of the water jet are what make it valuable  to oil
slick control. Once the  air begins to bubble up to the  surface water is brought  with it.
When  a  bubble  reaches the surface,  the displaced and  entrained water dissipates
radially outward from the burst bubble, forming a surface current.  The entrainment of
air  and the turbulent  nature of a  water jet hitting a water surface is  familiar to
anyone who has washed dishes in a sink and turned up the water pressure to agitate the
water and form soap bubbles.

       A water jet  can  be constructed of common pipe and fittings using any of the
many commercially  available pumps to supply  the water.  Properly assembled and
positioned, it can operate with  minimal supervision and provide rugged installation to
oil spill recovery work.  Workboats and shipping may  pass within a few feet of a float
with a water jet without damaging the oil slick control system.   In contrast, a fabric
boom could be  torn  or  sunk if a vessel were to sail into it.  In all  of  the  six test
programs conducted by the EPA Oil  and Hazardous  Materials Simulated Environmental
Test Tank (OHMSETT) (Appendix A), the  only problems encountered were improperly
assembled  hoses that parted because of  the  pressure, the water pump losing prime
after being shut down  after a  test, and an object  being lodged  in the nozzle of the
water  jet (e.g., a small  rock that was in the hose that supplied the jet).  All problems
were corrected within minutes.

       The technique of using streams and sprays of pressurized  water to control  oil
slicks has been  known for sometime.  Reports on the use  of .fire hose  streams  to
control oil slicks have been published by the U.S.  government. '   From  a literature
and patent search and from statements of  experienced oil spill cleanup contractors and
oil spill recovery equipment manufacturers, it was  found that the horizontal velocity
component of the water streams is  used  to  create a surface current  and move oil,
while ihe vertical component  is generally overlooked or directly  declared to  have  no
value.   The valuable vertical component of the coherent water jet is what this report
is primarily concerned with.

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      A feasibility test  to examine the usefulness of water jets as a substitute for a
fabric  transition  piece between converging  booms  and a  skimmer was  conducted
simultaneously with these tests and appears under a different cover.

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                                   SECTION 2

   EXPLANATION AND BASIC USES OF WATER JETS TO CONTROL OIL SLICKS


INTRODUCTION

       The development of the water jet  began  as  a method to Increase the accuracy
of testing oiJ  spill  control  and recovery devices at  OHM SETT.   Primary  to the
operations at the OHM SETT facility  is  the ability to control oil slicks  on  the  water's
surface after they have been deployed from the  oil  distribution system  so that the oil
slick  effectively enters the  device  being tested.  The oil  must be laid down on the
water at a sufficient distance from the device  to  allow  the oil to recover from the
shock of being deployed from a  moving source  (the main bridge) onto the stationary
water surface.  Deploying the oil from the "upstream" side of the bridge is sufficient
for the oil to form a fairly uniform layer  before it contacts the test apparatus intake.
However, the time between deployment and contact with the test device allows the oil
to spread laterally.  This spreading of the oil can cause some of the oil slick  to pass
around  the test device's  intake.  Such a loss of oil must be  estimated from visual
observations and thus can be very subjective.  These inexact observations can result in
test data that show more than 100% throughput efficiency for an oil skimmer.

       Several methods have been tried to control the width of an oil slick to conform
to a device's intake dimensions.  The use of rigid  oil  containment plates worked  well at
speeds to six knots in calm  water  and  regular waves.  However, when a harbor chop
wave condition was encountered, the plates were subjected to side forces large  enough
to destroy their structural  integrity.  The use  of  a  pair of flexible oil containment
booms was somewhat more  successful in harbor chop  conditions, but even  at  low
speeds in calm  water the turbulence caused by the floatation members and attachment
mechanisms of  the booms could adversely affect  the performance of the device being
tested.   Another method was the  use  of floating  ropes to guide the oil  to the test
device. Braided rope and urethane foam-covered rope worked very well in calm water
and waves at speeds  to six knots  (regular  stranded rope tended  to skid sideways on the
water's surface in the direction that the strands were wound).  However, with both the
booms and the  ropes insufficient  tension could result in the fabric or rope buckling and
folding  and causing turbulence, while too much  tension  caused  the rope or fabric to
bridge the wave troughs and allow oil  to escape beneath it.

      The use of fire hoses to push oil to or away from objects or to clear areas ahead
of an  advancing skimmer has been used for years at OHMSETT and led to the concept
of using water  jets for guiding oil.   Fire hose streams directed  at  the water surface,
move  oil primarily by two mechanisms.  The first is a current formed by the impact of
the high velocity water droplets from  the fire hose stream transmitting their energy to
the upper surface  of  the pool (horizontal component of water  stream).  A fire hose
stream  nearly  parallel to the water's  surface  creates  the highest velocity surface
currents and a stream directed vertically  into  the pool produces  minimum surface

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 currtr'Tv              " .             '.               '' • 3 Dv >irt
 almost  .         ,N  '   ------  ^- -i-,_-}'        - -ose stream is removed !ro:n
 the point of    : -< :.  r~ '.     oc ,' a,  >r  , ^    r    ,  .  c , <^st important for this report
 was the sui fctv_e cut.cTit p:oduced by  r:sjng  Du^L^i  uf air  which are entrained in  the
 water column  by the impact  of  trie  lire hose  stream on  the pool  surface  (vertical
 component of water  stream).  Air will  be entrained to a minimum depth with a Ire
 'nose  stream directed nearly parallel to the pooi surface while air  will be entrained tc a
 maximum depth with the stream  directed vertically into the  water.  Such a surface
 current will continue to be produced  after the fire hose stream is removed due to the
 many small bubbles which were driven into the water column and  rise  very slowly.  The
 resulting  low velocity,  enduring current can control an oil  slick  for a while after  the
 water jet has  moved on.   The length  of time  the  current exists depends upon  the
 amount of air entrained and the depth to which it was driven.  The tests at OHM SETT
 indicate that a strong jet  can  produce a current which can endure for more  than  60
 seconds.

       There are two primary  phenomena which  contribute to the  success of  a water
 jet (Figure 1).  The first (Phase 1) is the current initiated by the the outward  splatter
 of the water stream when  it contacts  the body of water. This action is instrumental in
 preventing oil  from being hit  by the water  jet  and subsequently  entrained  into  the
 water column.  A moving jet creates a slight elevation in water level directly in front
 of the impact  point.  The outward splatter and  slight surface elevation  combine  to
 create a mechanism  which parts an oil  slick directly forward  of the impact point of a
 moving water jet.  The second phenomenon  (Phase II) is produced by the air  which is
 entrained in the water by the jet  (Figure  2).   A current is  produced  by the rising
 bubbles, which  displace water from on top of them and draw water with them as they
 travel to  the surface.  When they reach the  surface, they push the last layer  of water
 out of the way and  then  burst.   The  water  following the bubble continues to  the
 surface and dissipates radially. The larger bubbles rise first and  fastest and produce a
 strong initial  current.   The smaller  bubbles rise slowly  and maintain  the  surface
 current even  after  the water jet  has been  removed from  the area.   A  turbulent
 interaction between jet and water body is  important to produce  a  large number  of
 small bubbles in order  to maintain the oil  slick in  a desired  location (Figure 3).  A
 stationary water jet will develop  a "crater wall" surrounding  the impact  point due to
 the bubbles trying to rise directly up into the jet  (Figures 4 and 5).

       A third oil moving mechanism is  produced only by a  moving water jet, or a jet
 in a current. This is  a wave train of rolling, breaking waves not unlike those produced
 by a  vertical solid staff towed through  a body of water.  These  waves give an initial
 push  to the oil by rolling it to the side of the path  of the  water jet. Each water jet
 produces two of these waves.  The first is developed as a bow wave originating at the
 point of impact.  The second is developed at  the point where the water surface rises up
 behind the jet directly  aft of the impact depression (Figure 6).  It has been observed
 that some oil entrainment results from  the turbulence produced by these  waves but it
 is not much since these waves seldom exceed  2 cm  in height.  Besides, the rising
 bubbles aid in bringing any  entrained oil  to the surface quickly.

      The work presented  in this chapter shows the ability of water jets to effectively
 move an oil slick in all  wave conditions  at high speeds without significantly entraining
oil. Although originally intended to prove the feasibility of  using  water jets to control
oil slicks for testing, the project was  expanded to investigate the use of water jets  to

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Small currents at various
levels replacing the water
being pushed or pulled to
the surface by the bubbles
e I
                                                Phase I - water flow from
                                                Impact of water stream
              o   Phase II - rising bubbles
                  push water aside as they
                  rise causing a water
                  current
                 Figure 1.  Section view of water jet action.

                                      5

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            A                     B                       C


A.  As  air bubble rises water is  pushed from on top and  entrained  behind,
B.  As  bubble reaches the surface the  last water layer is pushed radially
     outward in the surface.
C.  As  the bubble bursts the water entrained  beneath it is carried to the
     surface  and also  radially  dissipated.
        Figure 2.   Single air bubble rising  to the water's surface.

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                                                     cf.'^V/" ,".'&•- •«-
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    •3- **--      -     ~"  -   ^ •    -     -—A""-  ^**'
     ,,-,.»•  < -.«


        '
Figure  3.   An  underwater view  of a time lapse sequence of a
                     stationary  water jet.

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                                                                      4
                                                                     I,.-*
jv *. v* v/M 0 \v*^*™^fe.^'f-V '»*'''"'-,-.  _s ,"f



                 "^"' ''" *   •      '•-
                     Figure  3.   Continued.

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I   ' "  /' ", * ^ ^ J1 'v"/t '-  .* " -' f4 /"T V° 8 - L   « ** •**%. %C '^"""3




^^^^'SiLi*£^^!Jit«iLSil
Figure 4.  Stationary water jet—side view.

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i^l\~^^'^*^M
  Figure 5.   Stationary water jet--top view.
                    10

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                                         ''''i
Figure 6.  Moving water jet exhibiting characteristic  wave train
                             11

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converge a wide, thin slick into  a narrow, thick one.  Problems encountered by trying
to use fabric oil boorn to converge oil slicks  during recovery operations have proved it
to be an expensive  and low speed operation.  If water jets could be substituted for the
boom the operation could be simplified and sped up.

CONCLUSIONS

       Vertically directed  water jets  proved capable of moving and restraining an oil
slick on the surface of water at speeds up to 6 kt and in wave conditions (up to 1.2  m
wave h:-;^ht).
su'Tace,  a  re;at;veiy  nigh current  and tnick oil S..JCK  neec  be present  &eiore  a
substantial  amount  of oil can  penetrate  the crater  produced  by the  jet  and be
entrained beneath the water stream.  Very little oil entrainrnent was noticed even with
the thickest slick (5 mm) tested at a tow speed of six knots.

       Trie bow waves produced by the passage of the water jet helped to move the oil
initially.  Some oil is entrained by the bow  waves and wake produced by the jet, but
the oil remains near  the  surface and rises quickly as  it is  moved with the currents
produced by the rising bubbles.

       When  converging an oil slick, sufficient time must be allowed after the water
jet passes an area to  enable  the surface current to fully develop and to move the oil
slick before an oil skimmer can most effectively encounter the thickened slick. This
could be anywhere from 3 to 60 seconds depending upon the desired convergence.

       Three millimeter  thick oil slicks were not moved as easily  as  1-mrn thin oil
slicks.

       The best performance of  the converging water jet arrangement  was obtained
using two and three pairs  of  jets at a high pressure. At six knots a 4.5 m wide,  1.08
rnm  thick slick was converged to  a 0.6 m  wide,  8.1  mm thick slick in 10 seconds.
These results are most probably not the  maximum attainable using three pairs of jets.
Since the first pair of jets were positioned wide and forward of the oil slick their full
effectiveness was not utilized.

       From  the  single jet tests it was found that  the most  effective performance
occurred at the highest pressures with the largest nozzle at low tow speeds and at a
nozzle exit height of 0.4 to 1.0 m above the water's surface.

       The water  jet  system  performed well and was  free from major breakdowns
throughout the test program.  However, a slight burr on the inside of a nozzle could
cause the water stream to lose coherence and spray more.  The  penetrating and air
entraining  power of the jet  is thus  diminished and subsequently  oil slick movement
performance decreases.  Pipes and  nozzles  should be checked for imperfections  and
rocks and other foreign matter should be removed from  the hoses before  assembly.
                                        12

-------
       Given the problems  encountered with the other methods of  controlling an oil
slick for test purposes at OHMSETT, it is recommended that water jets be used until a
better method is found.

       Prior to employing a water jet system to move oil on water  the system should
be examined for burrs on the  insides of the nozzles  and foreign objects (e.g., small
rocks) in the piping.  Any flow disturbance decreases the jet efficiency.

       Methods  to  increase air  entrainr/ient  by  the  jets  should  be  investigated.
TEST DESCRIPTION
                   > en t
       The equipment  set up for the first test series (slick  convergence) consisted of
three pairs of nozzles mounted on the main bridge so as to direct a stream of water
straight  down into the water for maximum air  entrainrnent (Figure 7).  The nozzles
were  20  cm long,  1.6 cm ID bronze pipe nipples cut and trimmed to present a clean,
squared exit for minimum water stream spread.

       The first pair of nozzles (No. 1 and 2) were placed on either side of the 4.5 m
distribution manifold each 0.75 m outboard and  0.75 m upstream from the distribution
manifold.  The purpose  of  the upstream placement was  to ensure a  minimum of
entrainrnent of the Circo 4X light oil used throughout the entire test series.  Since this
was the  first  of a series of tests, it was not  known that  the jets could have been
positioned closer to the slick without  causing severe entrainrnent.  The light oil was
chosen due to its low viscosity which allows it to spread faster than any other oil used
in the standardized test procedures of  OHMSETT (Appendix B).

       The second pair  of nozzles (No. 3 and 4)  were placed  3.6 m north (downstream)
of the first pair and 4.5 m apart.  A third  pair of nozzles (No. 5 and 6)  were deployed
from  the north side  (downstream) side of  the  main  bridge  4.5 m apart and  3.8 m
downstream from the second pair of jets.   All jet  nozzle exits were positioned 1.8 m
above the water surface.

       Markers were trailed in  the  water at 15 and 30 rn from the oil distribution point
for reference  locations (Figure 8).  At 15 rn a length of small diameter conduit with
streamers tied every 0.3 m was suspended above the water's  surface to serve  as a slick
width reference device.  At 30 m two floats,  4.5  m apart, were trailed from the
auxiliary bridge.  A Polaroid camera mounted  on the auxiliary bridge recorded the
slick width at both marker locations.

       Water  to the jets  and oil for the slick were delivered by standard OHMSETT
equipment. The pump used to supply water to the jets  was the main bridge fire pump.
This pump is capable of delivering  111 m^/hr at  700 kPa. A maximum pressure of 420
kPa could be  obtained  with all  six jets in operations.  The oil distribution system used

-------
                            6 m
                                    ,-J
                                                     Pump
II  Oil    L-	
! ! Storage If  I    I
      "J|'pi   n
            rV   !  i
                      L   :aif~_J3	™
                        Distribution        f
J Oil     _
 ! Storaqei
                                            B ridge
 , i
                                                cm Poly  Rope
 Ol! distribution
 Test director
 Test engineer
jPump operator
jPhotoqraoher
 Pressure qauqe
 Water jet location


  Video Truss
                                  P  Tow
                                  Direction
                     onduit
                     1 cm  Poly Rope Streamers
                             9 m
               "tram era"
                                              Auxiliary
                                              BYidge
                                           i!
                                m
              Floats

                                                             15m
                                                               15 m
                                                         ,j]_
                                                         nil
     Figure 7.  Test set up for oi!  slick  convergence tests.

-------
       Main Bridqe
Auxiliary  Bridge
Oil
Distribution
Manifold
                    Second  Pair of
                    Water Jets
                                    Third Pair of
                                    Water Jets
                 Figure 8.  Section view of convergence test set  up.

-------
was a ^.5 rn  wide, three section  manifold with splashpiate  and  laxdown  T. •,=•;• j"Aie
utIJized in many of the tests conducted at OKMSETT to date.

       The second series  of tests used one  nozzle mounted in the  center of the north
side of the main bridge to split an  oil slick  (Figures 9 and 10).  This test was designed
to  eliminate confusion caused  by  interferences to  slick movement such as wind and
opposing currents generated by other water  jets. The same water pump was used as in
the  previous tests.  With only one nozzle being used  560  kPa of pressure could be
developed.  Both 2.1 cm  and  2.7 cm diameter  nozzles  were tested  to compare the
relative effect on  oil slick movement.  The nozzle height was fixed at 0.8 m above the
water's surface.  Two small wooden beams were assembled at right  a~ gles  to each
ether to form  a sighting Tool (Figure 11) to  monitor  the oil slick movement.  The lower
piece  was held against a rail  which ran  the  length of  the  main bridge  while the
operator  sighted  oversights  on  the  upper  piece at the edge  of  the  oil slick.   The
location of this inside edge of the parted slick was thus tracked.

       The test arrangement for the third  series of  tests was like that of the second
series  but added the  ability  to change  the  height of  the nozzle from the water's
surface.   A 2.1 cm ID nozzle was  used for these water jet tests and also for one test
using compressed air released beneath the water's surface.

TEST PROCEDURES

       The tests were so arranged as to determine the effects that various parameters
have upon oil slick movement.  The independent variables consisted of tow speed, wave
condition, number of water jets, water jet  pressure, nozzle size and height above the
water, and oil  slick thickness.  The  dependent variable was oil slick movement.

       The tests conducted for the convergence tests were run according to the test
matrix (Table  1).  Basically the tests consisted of the following:

       1.     Control tests in which a 4.5 m wide slick of 1,2, and 3 mm was deployed
             at 2, 4, and  6 knots to check  the actual spread of the oil  without  water
             jets.

       2.     Tests with 2, 4, and 6 water jet nozzles used at different tow speeds and
             pressures on oil slicks of different thicknesses.

       Preparations for a  test  run consisted of setting the oil flow to the rate needed
for a particular slick  thickness at  the test speed,  placing in operation the desired
number of nozzles and adjusting valves  to obtain  the  desired water  pressure.  The
bridge  was then brought up to speed and oil  distribution begun.  When the slick reached
the  15 m  marker the first picture  was taken.  The bridge speed was maintained while
the photographer swiveled the  camera for  a  shot of the slick at the  30 m marker.
After the second photo was taken,  the oil distribution was stopped, the  fire  pump was
secured, and the bridge was brought to a stop.  The skimmer booms were lowered to
skim the oil back to the north end of the tank.  The photographs  taken during a test
were examined and data recorded during the time the oil was skimmed.

       The nature  of the second and third test series necessitated that other matrices
(Tables 2  and  3) and test  procedures be developed.   It was necessary to continuously
                                        16

-------
                                        .ii JP  "anifo!d
                                   I d a e
Slick Ssghtinq
Tools
       1   Test engineer
       2   Test director
       3   Oil  distributor
       U   Oil  slick siqhter
       5   Oil  slick sighte
                                         A.u xj Ij a_ry_ _B rjd ge
Figure  9.   Test set up for single  water jet test,  slick parting  tests.
                                  17

-------

                                                     — Main Bridge
                                                       91  cm  I-b earn
                       5 cm
40 cm
               2.5 cm or
80 cm
  Figure  10.  Water jet nozzle  mounted on  the main  bridge.
                             18

-------
Figure 11.   M.G. Johnson  holding an OHMSETT oil  slick sighter.
                             19

-------
TABLE 1. MAT-I-  - ~-  ^'.i  >' CONVERGENCE TESTS
Test
no.
1
2
3
^
5
6
7
8
9
10
i!
12
13
1*
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Tow
s Deed
(kts)
2
4
6
2
4
6
2
4
6
2
4
6
2
4
6
2
4
6
2
2
2
4
4
4
6
6
6
2
2
2
4
if
if
6
6
6
if
if
if
if
if
if
4
Slick
thk.
(mm)
1.0
1.0
• i.o
2.G
2.0
": H
/. . u
3.0
3.0
3.0
1.0
1.0
1.0
2.0
2.0
2.0
3.0
3.0
3.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
2.0
2.0
2.0
2.0
Number
of nozzles
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
if
6
2
if
6
2
if
6
2
if
6
2
if
6
2
if
6
6
6
6
6
6
6
6
Pressure
CkPa)
0
0
0
0
0
r,
U
0
0
0
0
0
0
0
0
0
0
0
0
70
70
70
1*0
140
140
280
280
280
70
70
70
140
140
140
280
280
280
70
280
420
70
140
280
420
                                                          Calm
                                                          Calm
                                                          CaJm
                                                          Cairn
                                                          Calm
                                                          CaJm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          0,6 m HC
                                                          r, /•' „_, i) '•
                                                          u * c i Fi n \^
                                                          0.6 IT, HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          0.6 m HC
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                                                          Calm
                         20

-------
TABLE 2.  MATRIX FOR SLICK DIVERGENCE TESTS

Test
no.
i
2
3
k
5
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Tow
speed
(kts)
2 to 6
2
2
2
4
4
4
6
6
6
2
2
2
4
14
4
6
6
6
2 to 6
2
4
6
2 to 6
2
4
6
2 to 6
2
4
6
2
4
6
SJick
thk.
(mm)
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
3.0
3.0
3.0
3.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0

Nozzle
I.D. (cm)
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7 .
2.7

Pressure
kPa
0
140
280
560
140
280
560
140
280
560
140
280
560
140
280
560
140
280
560
0
280
280
280
0
560
560
560
0
280
280
280
560
560
560

Wave
(mm)
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
0.5x12.1
0.5x12.1
0.5x12.1
0.5x12.1
1.2 m HC
1.2 m HC
1.2 m HC
1.2m HC
1.2 m HC
1.2 m HC
1.2 m HC
                    21

-------
        TABLE 3.  TEST MATRIX FOR WATER 3ET HEIGHT EFFECTS

Test
no.
Tow
speed
(kts)
Nozzle
I.D.
(cm)

Pressure
(kPa)
Slick
thk.
(mm)
Nozzle
height
(m)


Wave
1
2
3
u
5
6
14
6
14
6
2.1
2.1
2.1
2.1
2.1
2.1
560
560
560
560
560
560
 .0
 .0
1.0
1.0
1.0
1.0
0.6
1.8
1.8
0.6
0.3
0.3
Calm
Cairn
Calm
Cairn
Calm
Calm
                                  22

-------
                          :he  oij s'ick.  Towing markers was impractical because the
slick  was to  be  observed for one ;n inure and a  large number of markers  would have
been  needed.  Besides,  the  n;arkers would  have been too far from the bridge to be
photographed well.  Time constraints prevented gridding the tank with small anchored
floats to  be  used a references.  The slick was monitored using the sirnpjy constructed
sighting  apparatus described earlier.  Two sighting boards  were slid along the rail on
the main  bridge until the operators v.ere lined up with the inside edge of the slick they
were  following.  Every  15 seconds, for  one minute, a position  reading was  taken from
both of the sight board operators.  The water jet nozzle was  mounted in the center of
the main  bridge so the readings indicated how far  the slick was split on either side of
the jet.  The original test plan was designed to  move the  water  jet down  one side of
the oil slick,  but wind would have biased the  'eacings.

DISCUSSION OF RESULTS

       The tests were successful in revealing how the independent parameters  tested
effect water jet performance.   The  graphs presented herein were developed from the
tabulated test  results  (Tables  4, 5, and  6).  Direct comparison of slick  movement
between the  convergence tests and oil slick parting tests is  difficult.  Oil movement in
the convergency tests was less than that recorded during the slick parting tests due to
the opposing currents developed by  the pairs of  jets and the  build up of oil  between
them. Other causes for the different results were the longer  pipe nozzles used in the
slick  parting tests and the difference in height  from  the water of the nozzles.  The
longer pipe (length greater than  15 ID) resulted in a more coherent water stream being
delivered. Such a water stream entrained air well without  the jet splattering  onto the
oil  slick  and thereby entraining oil.   A  coherent water  jet of the size  and at the
pressure tested performed best at a height of 0.^ to 1.0 m above the water's surface.
The parting  slick tests had the  nozzle  heights within  this preferred range while the
convergence  slick tests had nozzle heights above 1.0 m. However, general effects of
the independent variables can be qualitatively compared between the tests.  In this
regard the convergent  and divergent tests  can be discussed together.   The graphs
which depict the effects of the  parameters  are  clearly labeled as to which tests they
pertain to.

       The oil slick  sighters were tested against known widths  of  5 m over a 30 m
distance and resulted in  accuracy within 0.3 m.  Data for the slick convergence tests
were  taken from Polaroid pictures. The accuracy of this method was about the same.

       The effects of the independent parameters on oil slick movement are discussed
individually.

Tow Speed

       The time required to part a slick a given distance was inversely proportional to
the tow speed using the same water jet, (Figure  12). If  a water jet parted  a slick 3 m
in 15  seconds when run at 2 kts, the same jet would require  30 seconds to part the slick
3 m at ^ kts.  This  generally  held  for  the  slick convergence tests until  interaction
occurred between  the jets on either side of  the  slick (Figure  13). Such a relationship
would probably  break down  for  smaller water jets and faster tow  speeds.  Surface
tension effects  would probably  cause  a small water jet to  splatter somewhat upon
impact rather than penetrate and entrain air.


                                        23

-------
           TABLE 4A.  CONTROL TESTS, 29 AUGUST 1978, CALM WATER (SLICK CONVERGENCE TESTS)
K)
Test
no.
31
32
33
34
35
36
36R
37
38
39
39R
Speed
(kts)
2
it
6
2
*
6
6
2
4
6
6
Slick
thick
(30m
(mm)
i.
i.
0.
2.
2.
2.
2.
3.
3.
3.
3.
21
20
95
40
16
16
21
24
29
09
12
Slick
width
@15m
(m)
4.
4.
4.
5.
5.

5.
6.
6.
6.
6.
8
8
8
75
45

15
06
06
06
06
Slick
width % Expan
(B30 m (315 m
(m)
6.06
5.75
5.15
6.66
6.06

5.45
7.27
6.96
6.36
6.36
7
7
7
27
20
CAMERA MALFUNC'I
13
33
33
33
33
Slick
% Expan thick
@30 m @15rn
(rnm)
33
27
13
47
33
'ION
17
60
53
40
40
i
1
0
i
1

1
2
2
2
2
.13
.13
.89
.89
.80

.95
.43
.47
.32
.34
Slick
thick
(§30 m
(mm)
0.91
0.95
0.84
1.64
1.62

1.84
2.03
2.15
2.21
2.23

-------
         TABLE 4B.  CONTROL TESTS, 31 AUGUST 1978, 0.6 m HARBOR CHOP (5L
NJ
U1

Test
no.
40
41
i+2
43
44
1+5
46
47
48

Speed
(kts)
2
'4
6
2
4
6
2
4
6
Slick
thick
(90m
(mm)
1.27
1.02
0.97
2.04
1.62
2.11
3.23
3.18
3.62
Slick
width
@15 m
(m)
5.15
4.8
4.8
5.15
4.54
6.06
6.66
5.75
4.8
Slick
width
(d30 m
(m)
5.75
5.15
4.8
5.45
6.66
5.45
6.06
6.66
4.8

% Expan
(315 m
13
7
7
13
0
33
47
27
7

% Expan
(330 m
27
13
7
20
47
20
33
47
7
Slick
thick
(d!5 m
(mm)
1.12
0.96
0.91
1.80
1.62
1.58
2.20
2.51
3.39
Slick
thick
(§30 m
(inrn)
1.00
0.90
0.91
1.70
1. 10
1.76
2.42
2.17
3.39

-------
           TABLE *C. WATER 3ET TESTS, 30 AUGUST 1978, CALM WATER (SLICK CONVERGENCE TESTS)
NJ
01

Test
no.
1
2
3
>t
5
6
7
8
9
10
li
14
16

Speed
(kts)
2
2
2
'4
*
*
6
6
6
6
*
2
2
Slick
thick
(90 m
(mm)
1.1*
1.19
1.09
1.09
1.0*
1.15
1.16
1.08
1.01
1.11
1.03
0.92
1.11
Slick
width
(915 m
(m)
3.63
1.5
1.51
3.63
2.72
2.42
3.63
2.42
2.72
3.03
1.21
0.90
3.03
Slick
width
(930 m
(m)
2.72
2.12
1.81
3.33
1.51
0.90
2.72
0.60
0.90
2.72
0.90
2.72
2.72
Slick
thick
(§15 m
(mm)
l.*3
3.57
3.27
1.36
1.73
2.16
l.*5
2.03
1.68
1.67
3.86
4.60
1.67
Slick
thick
(315 m
(m m )
1.90
2.53
2.73
1.^9
3.12
5.75
1.93
8. JO
5.05
1.85
5.15
1.53
1.85
Number
of
nozzles
2
*
6
2
*
6
2
'f
6
2
?f.
6
2
Water
press.
(kPa)
70
70
70
1*0
1*0
1*0
280
280
280
560
560
*20
1*0

-------
TABLE 4D. WATER JET TESTS, 31 AUGUST 1978, 0.6 m HARBOR CHOP (SUCK_CONVERGENC1^TESTS)_

Test
no.
16
17
18
19
20
21
22
23
24

Speed
(kts)
2
2
2
it
14
4
6
6
6
Slick
thick
@0 m
(mm)
1.13
1.13
1.16
1.08
1.17
1.17
0.95
1.23
1.16
Slick
width
@15 m
(m)
3.63
1.81
2.12
3.93
2.42
2.42
3.93
2.72
2.42
Slick
width
(930 m
(m)
3.03
1.81
1.51
3.63
1.51
1.21
3.33
0.90
1.81
Slick
thick
@15 m
(mm)
1.41
2.82
2.49
1.25
2.19
2.19
1.09
2.05
2.18
Slick
thick
@15 in
(m m )
1.70
2.82
3.48
1.35
3.51
4.39
1.30
6.15
2.89
Number
of
nozzles
2
4
6
2
4
6
2
4
6
Water
press.
(kPa)
70
70
70
140
140
140
280
280
280

-------
NJ
00
          TABLE 4E. WATER JET TESTS, 1 SEPTEMBER 1978, CALM WATER (SLICK CONVIIR_^EN_Ci3_TESTS)

Test
no.
49
50
41
52
53
55
Slick
Speed thick
(kts) (§0 m
(mm)
4 1.05
4 1.08
4 1.05
4 2.26
4 2.21
4 2.26
Slick
width
@15 m
(m)
2.72
2.12
1.51
3.03
2.42
2.12
Slick
width
@30 rn
(m)
1.81
0.90
0.90
1.81
1.51
1.51
Slick
thick
@15 m
(mm)
1.5
2.31
3.15
3.39
4.14
4.84
Slick
thick
(ci 1 .5 1 1 1
(mm)
2.63
5.40
"5.25
5.65
6.63
6.78

Number
of
nozzles
6
6
6
6
6
6

Water
press.
(kPa)
70
280
420
70
280
420
       TABLE 4F. WATER 3ET TESTS, 1 SEPTEMBER 1978, 1.2 m HARBOR CHOP (SLICK CONVERGENCE_TESTS)

Test
no.
56
57
58

Speed
(kts)
4
4
4
Slick
thick
@0 m
(mm)
1.25
6.23
6.23
Slick
width
@15 m
(m)
1.81
2.42
2.42
Slick
width
@30 m
(m)
1.51
2.72
2.12
Slick
thick
@15 m
(mm)
3.13
11.68
11.68
Slick
tiuck
(ci30 m
(in m )
3.75
10.38
13.35
                                                                                     Number  Water
                                                                                     of       press.
                                                                                     nozzles  (kPa)
                                                                                     6
                                                                                     4
                                                                                     4
560
280
560

-------
                        TABLE 5. SINGLE 3ET TEST RESULTS (SLICK PARTING TESTS),
N)
U5
'""'•" 	 ' ' ' •— ' -
Test
no.
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
2>4
25
26
27
28
29
30
Tow
speed
(kts)
2
2
2
2
*
*
4
6
6
6
2
2
2
*
4
*
6
6
6
2
*
6
2
4
Nozzle
ID
(cm)
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.7
2.7
, 2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
Slick
thick
(mm)
0.9
1.2
1.2
1.2
0.8
1.0
1.1
1.0
1.0
1.0
1.4
1.2
1.2
1.2
1.2
1.2
1.0
0.9
1.1
2.7
4.8
3.3
1.4
1.1
Water
press
(kPa)
140
280
560
0
140
280
560
140
280
560
140
280
560
140
280
560
140
280
560
280
280
280
560
560
Wave
Calm
Calm
Cairn
Calm
CaJm
Calm
Calm
Calm
Calm
CaJm
Calm
Calm
Cairn
Calm
Cairn
Calm
Calm
Calm
CaJm
Cairn
Cairn
Cairn


15
2.4
2.7
3.4
7.6
2.0
2.2
2.2
i . 3
i.S
2, I
7,7
2.8
4.2
j.8
2.4
2.7
2.0
2.1
2.7
3.0


3.6
2.4
Elapsed Time (sec)
30 45
Slick Movement (m)
2.8
3.4
4.2
8.0
2.4
2.6
3.0
1.8
2.3
2.6
3.5
3.6
5.1
2.6
2.9
3.5
2.6
2.8
3.2
4.5


3.9
3.6
3.1
3.8
4.5
8.5
2.4
2.9
3.8
2.3
2.7
3.0
3.8
4.2
5.4
3.0
3.6
4.4
2.9
3.5
3.8
5.0


4.8
4.2
60
3.4
4.0
4.8
8.8
2.6
3. I
4.5
2.5
2.9
3.1
4.i
4. 5
5.7
3.2
4.5
5. J
3.2
3.9
3.9
5.4
3.5
3 . 4
5.8
4.7
                                                           (Continued)

-------
                                             TABLE 5. (Continued)
Test
no.

31
32
33
34
35
36
37
26R
21R
22R
Tow
speed
(kts)

6
2
4
4
2
6
6
2
4
4
Nozzle
ID
(cm)

2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
Slick
thick
(mm)

0.7
1.3
0.7
1.1
1.3
0.9
0.9
3.5
1.1
0.9
Water
press
(kPa)

560
280
560
280
560
280
560
280
280
560
Elapsed Time (sec)
Wave 15 30 45
Slick Movement (m)
2.3 3.3 3.6
1.2HC 2.1 3.0 3.9
I.2HC 3.0 4.2 5.2
1.2HC 2.1 3.3 3.5
1.2HC
1.2HC
1.2HC
Calm
Calm
Calm
60

14,2
4.5
4.9
3.7
6.1
2.7
4.r,
4.2
3.6
4.8
U)
o

-------
TABLE 6. WATER 3ET HEIGHT EFFECTS TEST RESULTS (SUCK PART
                                                                                 TESTS)

Test
no .


i
2
3
14
5
6
7
8
9*

Tow
speed
(kts)

4
6
6
it
4 to 6
* to 6
4
6
*

Nozzle
ID
(cm)

2.1
2.1
2.1
2.1
Observation
Observation
2.1
2.1
2.1


Height
of exit
above
(m)
0.
0.
1.
1.
run
run
0.
0.
-0.
water

6
6
2
2


3
3
6

Slick
thick
(mm)

3
3
3
3


3
3
3

Water
press.
(kPa)

560
560
560
560


560
560
210
.., „

Wave
(in)

Cairn
Calm
Calm
Calm
Ca 1 m
Cairn
Calm
Cairn
Calm




2
2
1
1
2


2
2
1


10

.if
.3
.6
.0


.7
.6
.7

                                                                             l:lapsed Time (sec)
                                                                                  20       30
                                                                               Slick Movement (m)
3.2
2.8
2.2
3.0
2.9
2.6
1.7
3.9
3.4
2.5
3.3
3.4
2.8
1.9

                                                                                                  3.6
                                                                                                  2.8
                                                                                                  3.5
                                                                                                  3.6
                                                                                                  3.1
                                                                                                  2.0
*Test run with 210 kPa of pressurized air being fed through a 2.1 cm ID pipe extended 0.6 m below the water's surface.

-------
00
NJ
s
L
I
D
K

M
0
V
E
M
E
N
T

I
N

M
E
T
E
R
S
                                                   A- 2  KTS
                                                   D- 4  KTS
                                                   0-6  KTS
                                                                                   -A

                                                                                   ..0
           1  -
           0
                                                38
                                             TIME CSECONDS)
                                                            45
60
    Figure 12,  Effect of tow speed on oil slick movement -  1-mm slick, calm water, 2.1-cm ID nozzle at  560
    Kpa (slick parting  tests).

-------
  s
  L
  I
  C
  K

  W
  I
  D
  T
  H

  I
  H

  M
  E
  T
  E
  R
  S
A-
Q~
0-
2 KTS., H0  KPa,  2
4 KTS., 140  KPa,  2 JETS
4 KTS., 288  KPa,  2
6 KTS., 280  KPa,  2 JETS
                              10          15          28
                      DISTANCE FROM  DISTRIBUTION POINT CMEIERS)
                       _l	
                        25
                                                                                       „.		i
                                30
Figure  13.  Effect of tow  speed on oil slick  movement - 1~mm slick thickness,  cairn water,  2.1-cm ID
nozzles (slick convergence tests).

-------
       Non-breaking waves appeared to have little or no effect on water  jet perform-
ance (Figures 14 and  15).  Inherent difficulties  in distributing a uniform  slick onto a
harbor  chop sea  state  resulted  in  oil slick  width  variations.   Such variations can
account for the relatively  minor  deviations of the harbor chop results from the calm
water results.
       Trie results declare that the more water jets that are employed, the greater the
control of the oil slick (Fiure 16).  This is reasonable since surface current controls
te  o   sc  an   trie more water  ets  n
produced.  Since the slick  parting tests  used only one nozzle in the tests  there  is no
graph from those tests to illustrate this point.

        eTr essure
       The greater  the  water jet pressure  the  greater  the  control over  the  oil slick
(Figures  17  and  18).   However, in the  convergence  tests there  was  a  point of
diminishing returns.  For the first  15  m  in  the  6 nozzle case at 4 knots,  140 kPa
pressure was sufficient to move the oil slick from 62 to 88 percent of the distance that
water jets using 420 kPa moved  the slick.  For the second  15 m,  140 kPa moved the
slick 100% of  the distance moved using 420  kPa.  When  using only  two nozzles the
higher possible pressures resulted in greater slick control  over the entire observation
time (Figure 16). These tests also showed that a converged slick will spread  again
quickly once the  currents produced by the two water jets subside.

Slick Thickness

       The slick  convergence tests showed  consistently  that  the thicker the oil  slick,
the  more difficult it is  to move (Figure  19).  With  the  arrangement of water jets
tested, a 4.5 m wide oil  slick of 1 to 2 mm thick could be thickened to 5 to 6 mm, (3 to
5 times as thick). The spreading  forces of  the oil and jet interaction appear to limit
convergence and thickening of an oil slick beyond this. A thicker slick of 6.23 mm was
driven to a 13.35 mm thickness. However, this is a reduction of width and an increase
in slick thickness  of only a  factor of 2.14.  The slick parting tests were not as
consistent with their results (Figure 20).  Some tests turned in higher performance in a
thicker slick while others delivered the expected poorer  performance. Since a thicker
oil slick spreads faster than a thin slick, parting a heavy slick should be more difficult
than parting a thin  slick.   The  better  performance in heavy slicks is probably an
abnormality in  the data caused by wind and/or errors in slick sighting.

Nozzle Size

       The larger the nozzle the better the performance  at the same pressure. The 2.7
cm   ID nozzle  outperformed the  2.1 cm ID nozzle at all speeds  tested.   A typical
comparison is presented for the four knot tests (Figure 21). This result is logical  since
more water will flow through a larger pipe than a smaller pipe for a given pressure. A
greater fluid flow should be expected to entrain more air and thus create a stronger
surface current.

-------
w
I
D
T
H

I
N

M
E
f
I
E
R
A
F
T
E
R

3
8

S
E
C
                                        A- CALM WATER
                                        D- 8.6 H  HC WAVE
                      SLICK WIDTH AT OIL DISTRIBUTION  POINT
    L
    8
     • 8
                                                                             Q
                                                         			l_
                            234
                               NUMBER OF  NOZZLES  USED
5
6
,£ 1'K.^ater Jef Performance.. in 'calm water and waves - 1-mm slick,
kPa (slick convergence tests).
                                                                  kt, 2.1^cm ID nozzle at
                                                                                 «"•« «i

-------
  s
  L
  1
  C
  K

  M
  0
  V
  E
  "if
  E
  N
  T

  I
  N

  M
  E
  T
  E
  R
  S
7 h
6 -
A- CALM WATER,  580 KPa
D- 0.3  H HC,  580 KPa
<>- 0.7  H HC,  280 KPa
+ -0.6  H RES,  560 KPa
°~ CALM,  280  KPa
4 L
                                       30
                                    TIME CSECONDS)
                                                 45
                     68
Figure 15.  Water jet performance in calm water and waves - 1-mm slick,  2.6 cm ID  nozzle  U kt  (slick
parting tests).    .                                                            '

-------
  s
  L
  I
  C
  K

  W
  1
  D
  T
  H

  I
  N
  E
  T
  E
  R
  S
                  A- 8 NOZZLES
                  D- 2 NOZZLES
                  0-4 NOZZLES
                  f- 6 NOZZLES
                      :SLICK WIDTH AT  OIL DISTRIBUTION POINT
                                             RESPREAD1NG OF THE  SLICK
      18          15          28
DISTANCE  FROM DISTRIBUTION  POINT
                                                           CM)
Figure  16.  Effect of the number of water jets on oil  slick movement - 1-mm slick, 2 kt  1 6-cm ID
nozzle at  70 kPa (slick convergence tests).

-------
Ul
CD
         0
                                              A - 0 NOZZLES
                                              D~ 78 KPa
                                                      KPa
                                                   SLICK  WIDTH  AT OIL  DISTRIBUTION POINT
                                                                            OF THE SLICK
      10
DISTANCE
        15
FROH DISTRIBUTION
                                                         28
                                                         POINT
                  30
CM>
    Figure 17.   Effect of water jet pressure on oil slick movement - 2 kt, 1-mm slick, 2 nozzles,  1.6-cm ID
    nozzles (slick convergence tests).

-------
U)
(JO
s
L
I
C
K

M
0
V
E
M
E
N
T

I
N

M
E
T
E
R
S
                                                A_  148 KPa
                                                D-  288 KPa
                                                0»  568 KPa
                                                                               •-A
            0
                      15
  38
TIME  CSECONDS)
60
    Figure 18.  Effect of water jet pressure on oil movement - 2 kt,  1 -mm slick,  2. 1 cm ID nozzle  (slick
    parting tests).

-------
  s
  L
  I
  C
  K

  W
  I
  D
  T
  H
   N

   M
   E
   T
   E
   R
   S
                   A- 1 MM, AFTER 15 SECS, CALM
                   D- 1 MM, AFTER 7.5 SECS, CALM
                   0- 2.2 MM,  AFTER 15 SECS,
                   •f- 2.2 M,  AFTER 7.5 SECS, CALM
                   0- 6.23 MM,  AFTER 7.5        1.2 M HC
       SLICK WIDTH  AT OIL DISTRIBUTION  POINT
        8
50
180      158      280      258
       WATER JET PRESSURE CKPeO
388
350
408
Figure  19.  Effect of water jet pressure and slick thickness on oil  slick movement 4 kt, 6 nozzles
cm ID nozzles (slick convergence tests).
                                                                      -1.6-

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  s
  L
  I
  C
  K

  M
  0
  V
  E
  M
  E
  N
  T

  1
  N
  E
  T
  E
  R
  S
            A_ !  MM,  288 KPa,  2 KTS
            D-2.7 MM,  280 KPa,  2 KTS
            0- i  MM,  280 KPa,  6 KTS
             -3.3 MM,  280 KPa,  6 KTS
* UNUSUAL RESULT SINCE THE THICKER SLICKS SHOULD
  MORE DIFFICULT TO MOVE.
                                     38
                                   TIME CSECONDS)
Figure 20.  Effect of slick thickness on oil slick movement - 2.1-cm ID nozzle (slick parting tests).

-------
4=
K)
s
L
I
C
K

M
0
V
E
M
E
N
T

I
N

M
E
T
E
R
S
                                   A-
                                   D-
                                   0-
568 Kpa,  2.7cm ID  NOZZLE
560 Kpa,  2.1cm ID  NOZZLE
140 Kpa,  2.7cm ID  NOZZLE
148 Kpa,  2.1cm ID  NOZZLE
          4 I-
                                             38
                                          TIME CSECONDS)
    Figure 21.  Effect of nozzle diameter on oil  slick movement  in calm water, 1-mm  slick  H kt fslick
    parting tests).

-------
Nozzle Heijght

      The best performance was  achieved  when the nozzle exit was  0.4 to  1.0 m
above the water's surface (Figure 22).  Above the optimum  height the water  stream
was given a chance to spread and it lost its  coherence.  Penetration  was reduced and
thus the amount of air entrained  was reduced. Below the optimum height the jet did
not have enough time to fully develop the  turbulent boundary layer which transported
air  along  with  it into the receiving water.  The result  was the same as having the
nozzle too high—less air was entrained into the water column  and thus less surface
current  was produced.  The crater  which served  to  prevent  oil  from getting  beneath
the jet was  also reduced in  both  cases and more  oil  entrainment resulted.  This result
may not hold true for  other  types of nozzles or water pressures not  in  the range
tested.

      The waves produced by a moving jet were  observed to entrain oil to a maximum
depth of about  15 cm.  The oil rose quickly to the surface as it  moved away from the
point of impact. The jet was  recorded to entrain air to beyond  1 meter depth.  No oil
was seen to be entrained to such depths.  This gave good evidence to the effectiveness
of the crater to part the oil slick and keep it from  beneath the water jet.  The rapid
rise of the wave entrained  oil to  the surface was  probably the  result of  the small
bubbles  of air entrained by the jet rising into the oil droplets and making them more
buoyant.

      A nomograph  was developed from the results of the  convergence tests  (Figure
23).  It is  used to determine the size and number  of water jets and the water pressure
to the jets  necessary to converge a 1 mm  oil slick  at  four knots.   A different
arrangement of water jets would render a different nomograph.

      To  use the nomograph one must decide how wide of  a slick (e.g.  3 rn)  is to be
converged to the necessary width (e.g.  J m).  A straight line is drawn  between  the two
widths.  The number  of nozzles (4) and the pressure necessary (90 kPa) is read from the
scales.

      A test run was carried out using a submerged pipe discharging compressed air to
part an oil slick. A 50 Kw, gasoline engine  air compressor supplied the 2.0 cm ID pipe
with 210 kPa air pressure.  The tests were  run at four knots and calm water through a
1 mm slick.  The results showed a very clean  path cut through the oil, but the oil slick
movement was significantly less  than  that produced by a 2.1 cm  ID  water jet at 140
kPa water pressure  (Figure 24).   During tank cleanup one  day, a 6.1 cm ID   hose
connected to a 225 Kw, 1250 m^/hr air compressor was used to  move oil away from a
tank wall. The  air pressure was approximately 560 kPa pressure.  The  air was directed
at the oil slick from above and  it was  also submerged  to bubble up air.   In  all
configurations attempted, the compressed air source could not match  the oil slick
movement capability of a single  2.1 cm ID fire hose at  approximately 420 kPa water
pressure.  The power  required to drive the fire hose was about 20 Kw.
                                         43

-------
   s
   L
   I
   C
   K

   M
   0
   V
   E
   H
   E
   N
   T
6
NOZZLE
HEIGHT
A- 8.6 H,
D- 8.6 M,
0- 1 .2 M,
+ - ! .2 H,
0- 0.3 H,
• - 0.3 M,
TOW
SPEED
4 KTS,
6 KTS,
4 KTS,
6 KTS,
4 KTS,
6 KTS,
WATER
PRESSURE
ALL AT 568 KPa
                             X- -8.6 M, COMPRESSED  AIR, 4  KTS, 210  KPa
                                           28
                                        TIME CSECONDS)
                                                      30
48
Figure 22.  Effect of water jet nozzle height on oil slick movement
nozzle  (slick parting tests).
                                                          1-mm slick, calm water,  2.1-cm ID

-------
Distribution
Slick Width (Meters)
Nozzle
Number
             1.58cm ID SCH 40
                   Nozzle
        -4
              1.25 en ID SCH 40
                    Nozzles
     — 0.5
Water Jet
Manifold
Pressure (KPa)
                                              • 420

                                              •280

                                              • 140



                                             — 150
Desired Slick
Width at 15 M
                                              •0,5
                                              •70
                                              •35
     Figure  23.   OHMSETT  water jet nomagraph used for converging
                          a 1~mm slick at 4 kt.

-------
4=
en
      Z   7 ~
M
0
V
E
M
E
N
T

1
N

M
E
T
E
R
S
          6 »-
            8
                                       A- 148 Kpa,  WATER  JET
                                       D- 280 Kpa,  WATER  JET
                                       0- 568 Kpa,  WATER  JET
                                       i- 210 Kpa/  AIR
                                        28
                                     TIHE CSECONDS>
38
48
     Figure 24.  Comparison of water jet performance to that of a compressed air source,  1-mm slick  calm
     water, 2.1-cm ID nozzle, (siick parting  tests).

-------
                                   SECTION 3

              WATER 3ETS MOUNTED ON A MOVING OIL SKIMMER
INTRODUCTION

       To have a practical application to large scale oil spill recovery, the water jets
must  be able to be mounted  and perform  well  on a  moving  oil skimmer.  Tests
conducted  at  OHMSETT  in this regard were designed  to  develop  an  oil converging
system to be incorporated with the U.S. Coast Guard's Zero Relative Velocity (ZRY'j
fast current oil skimmer^ (Figure  25).  The objective was TO converge a 6 m wide slick
in to a 2.7 m wide slick (oil skimmer inlet size) at 6 knots in various wave conditions.
Since the principle of the ZRV skimmer consisted of oil absorbtion and adsorbtion onto
a floating composite belt, the  oil slick had to be on the surface when  it was in the
reduced width.  Oil entrained during the slick convergence  would not be recovered by
the skimmer.

       The test  program looked at the ability of  a pair  of water  jets to converge a
slick while mounted on a  catamaran and at the entrainment developed by the water
jets.  The independent variables of the test were water jet  nozzle size, tow speed, oil
slick thickness, wave condition, water pressure, number of water jet nozzles in service
and water jet nozzle attitude.   The dependent variables were oil slick movement and
the amount of oil entrainment.

CONCLUSIONS

       Water jet booms can be  successfully incorporated onto a moving oil skimmer to
converge a wide thin slick into a narrow thick one for easier  oil recovery.

       Vertically directed jets proved to be the best all-wave performers.  Angled jets
performed slightly better  than  the  vertical jets in  calm  water,  but performed
erratically in wave situations.  The point of impact of a stream from angled jets and
the distance between the nozzle exit and the point of impact changed drastically when
the long booms on which  the jets  were mounted reacted to the  catamaran's pitch and
heave in waves.

       Using  the electric  motor driven fire pump  available on the OHMSETT main
bridge, the best performance at different tow speeds by  water  jets on the 7.25 m is
presented below:

-------
00
                         Oil
                                                        Pipe Boom
                                              -Water jet nozzle   ,.,.;.:.:v;wS  ;•;:;•
                   Figure 25.   USCG ZRV skimmer using water  jets to sweep  oil

-------

Tow
speed
kts
2
*
6

Nozzle
size
cm
2.1
2.1
2.1


Pressure
kPa
210
560
600
Water jet
angle
in/fwd
degrees
0/0
20/0
10/45


Wave
cond.
calm
calm
calm
Orig.
slick
width
m
6.1
0.2
6.1
Final
slick
width
m
1.7
1.1
2.9

Slick


movement
m
4.4
3.2
3.2




Note:  Not alJ nozzle sizes were tested at all pressures and tow speeds.

       A satisfactory  boorr, length ior a water jet off the bow of a skimmer 10 to 15 m
in length appears  to  be from  6  to 12  m.  A  longer water  jet extension improves
performance in cairn  water.  However, any pitching and  heaving of the vessel is
amplified by the long boom.  If the boom is too Jong,  vessel movement can cause  the
water  jet  to be  raised  high above the water's surface and  plunged into the water
regularly.  Such action renders the water jets ineffective.

       The stationary tests revealed that some oil is entrained by a passing water  jet,
but that almost all of the oil slick remains on  the  surface.   Oil that is entrained is
carried away from the water jet impact point as it rises to the surface.   The angled
jets appeared to entrain more oil.

       A pair of water  jets can be expected to  essentially double the sweep  width of
the U.S. Coast Guard's ZRV skimmer from 2.7 to 5.4 rn at speeds up to  4  kts.  To
perform  as well at 6 kts a longer boom would be  required.

RECOMMENDATIONS

       Designs  of collapsible  water jet booms should be investigated.  Transportability
and longevity of the booms would be  enhanced if they could be folded for  storage on
the bow of a skimmer.

       Water jet/skimmer tests should be conducted with the  skimmer traveling with
the waves to reduce the pitch and heave of  the vessel.

       The U.S. Coast Guard Zero Relative Velocity Skimmer should be fitted with
water jet booms divided into two 3 m and two 1.5 m sections  for each side.  A suitable
length  boom can  then be assembled depending upon skimming operations  and  sea
conditions.

       The water  jet  boom  sections should be  stiffened and reinforced  to eliminate
whip from  the booms  when operating in waves and to withstand rough handling.  Such
protective construction could be placed inside  the  boom pipe rather than outside as
was done for the system used in these tests. Using internal reinforcing members would
require special consideration to  ensure adequate water flow with minimal  pressure
drop.

-------
TEST DESCRIPTION

Test Equipment

       The OHMSETT catamaran, IDA m long and 9.1 m wide was mounted with two
vertical stanchions to support the water jet booms.  A movable collar was placed at
the base of each stanchion to mount the water jet booms (Figure 26).  The water jet
booms were constructed from sections of aluminum  pipe welded together.  The  pipe
served as a structural member and as a conduit for  the water  used by the jets.  The
booms were supported and held  in place by  0.32 cm aircraft  cable and  turnbuckles
(Figure 27).   The water jets were  constructed as to allow  rotation in every piane
(Figure 28). Operators were  able to  splay the booms  to various widths, angle the jets
in towards the centerline of  the system and tilt them forward.  The waier jet nozzles
were  30 cm Jong standard pipe of various inside diameters (i.e.  1.25, 1.6, 2.1, 2.7 cm).
The nozzles were  wrapped with bands of black tape for identification in photographs.
The smallest had one band,  the next size had two, the next size had three and the
largest had none.

       The catamaran with stanchions and booms was placed in the tank and rigged for
towing by the main bridge (Figure 29). The main bridge fire pump supplied the water
jets via 5 cm diameter hoses. Pressure gauges were mounted along the water jet boom
in order to determine the water pressure  close to the water jet outlet.

       Oil was  distributed from  either a manifold or  individual  outlets located on the
south side of the main bridge. For oil slicks greater than b.5 m  in width  the individual
outlets were used, otherwise the oil manifold was used.  Medium oil (see Appendix B)
was used for these tests since its properties  most closely match those of the kind of oil
which  the U.S. Coast Guard determined the ZRV skimmer would be  recovering in
actual oil spill situations.

       To observe  the oil entraining properties of a water jet, the catamaran was held
stationary in  an oil slick with the water  jet nozzle positioned directly above an
underwater window (Figure 30).  The boom was swung through an arc by pulling it with
a rope from the video bridge. The rate of swing was  calculated to have the water jet
moving at about 4 knots. The action of the water jet impacting the oil and water was
recorded  via  slow-motion 16 mm movie photography  and sequential  35  mm  still
photography  through the underwater window  (Figure  31 A  through K).  A small
workboat was  positioned against the  tank wall over the underwater window to prevent
oil from being driven down onto the glass by the water jet.  A barrel was positioned on
the tank deck to receive  the flow from the water jet prior to the test.

Test Plan

       All tests were conducted according to the following test procedures:

       1.     Prepare appropriate photo/video equipment (shoot test record boards).

       2.     Prepare oil distribution for  tow test or stationary slick.

       3.     Adjust the  water jet nozzle and booms to the appropriate  angles.*
                                         50

-------
                                                                     / M
p


I-
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'4£-4?-<*V?'r*
                                         Stf,
                                         m, a*1 ffisJ
                                 ?!lLi2R^ac  Ji MJi^a',*r >j , _J «aJ».ti >-«.»• «AJji'*-j»-»^
       Figure 26.   First generation  water jet  booms
                                   51

-------
in
NJ
                             iwo sections of reinforced e.iuminum pipe
                                       (10 ft. ep.ch)
                                                                OEM8EII C.Vonmaran
                                                              Direction of Tow
          Water
          Jet
          Nozzle
Water
Supply
Hoses
               Figure  27.  Second generation  water jets mounted on OHMSET I catamaran,

-------
Vertical
Stanchion
Moveable
Collar
      Longitudinal Swivel
      Joint
                                                                                              90° Elbow
Ploe Unioi
                                                                                             Water Jet
                                                                                             Nozzle
                       Figure  28.   Details of second generation water jet.

-------
Figure 29.  Test set up for oil  skimmer/water jet  tests.

-------
                                      OH distribution  manifold
  P0*_i	
           t


          J;


     S
      1
      2
      3
      4
      5
      6
Test engineer
Test director
Oil  distributor
Boom operator
Photographer
Photographer
                     Main
                     Eridqt
                     6
                                                            * - f . L I
                                                            |; J 1 1 J:  U/W
                                                              * • '
                                                                   Window
                             OHMSETT
                             Catamaran
                                          iliarv_ Bridge	
55-gaIlon
drum
                                                                   Water
                                                                   Jet
                                                                   Boom
Figure 30.   Test set up for stationary tests - pivoting  a  water jet boom,
                                    55

-------

         '£L~. •=-— —  - -„  ~—. - -«^««^-^**^i&^»»S?>r:-»^^^S
         r:--r."  -

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         *-^
-------
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F:-.rf*s^^jfc*^w^
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                   Figure  31.   Continued.

-------
                                       ; ,-•;. :\'Xffl.

                            '  ~  '} -' ::; -,-f '^Vk'LT'-'f
                            \',- '• r5  '" / ',;" ," "  .I,'1', *

Figure 31.   Continued.
              58

-------
                         <:':•£$$
•i.-f£"ti'"\™'~'*.33.:?T,^\"':~yxv asr: "n.y
    Figure  31.   Continued.
                 59

-------
'
                  Figure  31.   Continued.
                                60
     S,-   ,-^-         -  _--"•••      '••     \
V| * " ff' 6 '  "u"--i  ' -   ', '"^"•Kw        ,           -~                              .pf
 Oi>viIi»W*i&* ^'tfid^vatofaL •;M^T-!;^/"---\/^ f*_-f;/— -.u-i.f ,»*^,fc*w
-------
       *f.     Obialn the desired se& state.

       5.     Start the water pump and bring the water jet to the correct pressure.

       6.     Alert the photo video department that the test is commencing.

       7.     In the case of a stationary test  the oil  slick  was distributed, the bridge
             horn sounded and the boom swung through the oil slick.

       S.     In the case of a tow test the  bridge horn 'was sounded, the tow begun and
             oil distribution begun when the correct tow speed was  achieved.

       9.     At trie  conclusion 01 the test  run remove the oil from  the water's surface
             using the skimming boom or fire  hoses.

       10.    Prepare for the next test.

*Consistent sweep widths were  maintained for lest comparison purposes.  In order to
compensate for the movement of  the water jet impact point due  to the inward angle of
the nozzle, the boom splay angle was adjusted.

        Both tow tests and  stationary tests  were conducted  according to matrices
(Tables 7 and 8) developed by the OHMSETT engineering staff in conjunction with the
US EPA project officer. The results from the tow tests (Table 9) were organized to
clarify the relationship of the independent parameters to  the dependent parameters.
The stationary tests were qualitatively analyzed and are commented on later in this
report.  Due to time constraints, all of the tests in the original test  matrices could not
be run.

       The objective of the first pair  of water jet booms made was to be from 6  to 12
rn long, strong enough to survive in waves and light enough to be  handled and supported
easily.  The booms  were constructed from  1.8 m sections of 6.^ cm ID  standard
aluminum  pipe welded together.  The first boom failed at a  welded  point due to the
force of the water inside of it and the guy wire forces outside. The joint was rewelded
and stiffeners were incorporated at each joint to add strength. Stiffeners were not
welded  over the entire length of the  pipe boom until  the next generation of water jet
booms were made.   The repaired booms proved able  to support themselves and the
water with the aid of the guy wires but they were still too flexible.  During tow  tests
in the 0.5 m harbor  chop,  the water  jet on the end  of  the  12  m  boom was whipped
between 3 m  above the water's surface and  0.5 m below the  surface due to vessel
pitch.  The flexibility of the boom also caused problems in rigging the booms on the
catamaran since the  guy wires supporting the boorns placed loads down the longitudinal
axis  of the boom.   Any twist  of the  collar which  held  the  boom to the vertical
stanchion  caused a bow to develop in the aluminum piping of the  boom. As  a result the
collar had to be positioned carefully on the stanchion  and tightened hard to prevent it
from turning.  Despite the problems, the booms performed well through the seven days
of testing.

       The second generation of water jet  boorns were made  from 3 m sections of 7.6
cm ID standard aluminum pipe with three  0.6^ cm x 3.8 cm aluminum strips welded
symmetrically (120°  spacing) down the length of the  pipe (Figure 27).  Standard weld

                                         61

-------
"ABLE 7. WATER 3ET/O1L SKIMMER FEASIBILITY TEST MATRIX


Test
no.
SD-1
SD-2
1
2
3
4
5
6
T
&
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

Tow
speed
(kts)
0-4
0-6
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
' 4
2
4
6



Wave
Calm
Calm
Calm
Calm
Calm
Cairn
Calm
Calm
Cairn
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm

Slick
thk
(mm)
0
0
2
2
2
2
2
2
z
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2

Slick
width
Cm)
0
0
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
4.25
6
6
6

Nozzle
ID
(cm*

—
—
2.1
2.1
2.1
2.7
2.7
2.7
1.5S
1.58
1.58
1.58
1.05
1.05
1.05
1.05
1.05
1.05
1.58
1.58
1.58
1.58
2.1
2.1
2.1
2.7
2.7
2.7
2.7
2.7
2.7
2.1
2.1
2.1
2.1
2.1
2.1


No. of
nozzles*
0
0
0
1
1
1
1
I
1
1
i
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
3
3


Pressure
(kPa)
0
0
0
210
420
560
210
H20
550
210
420
560
690
210
420
690
210
420
690
210
280
420
690
210
420
560
420
420
560
210
420
560
210
420
560
210
210
210
Nozzle
angle
in/iwd
(deg)
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
n / n
v W
0/0
0/0
0/0
0/0
0/0
0/0
0/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
10/0
20/0
20/0
20/0
20/0
20/0
20/0
0/0
0/0
0/0
Length
of
boom
(m)

—
7
7
7
7
7
7
•7
"7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
                                                  Continued
                           62

-------
"ABLE 7. (Continued)
Test
no.
37
3£
•a a
40
ill
U2
143
ij L
145
46
47
48
H3
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
Tow
speed
(kts)
14
14
f:
4
14
<4
4
b
l±
4
it
14
4
14
14
14
4
14
14
It
4
14
t4
14
6
6
14
4
6
6
14
14
6
6
2
14
6
Wave
Cairn
Cairr.
Calm
Calm
Calm
Cairn
Calm
CaJm
Cairr
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
0.5m
0.5m
0.5m
Slick
thk
(mm)
2
2
*~t
_/
2
2
2
2
2
*/
2
2
2
2
2
2
2
2
2
2
2
TBD
TBD
2
2
2
2
2
2
2
2
2
2
2
2
HC
HC
HC
Slick
width
Cm)
6
6
6
6
6
6
6
6
t
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
2
2
2
Nozzle
ID
(cm)
2.1
1.58
1.58
1.5&
1.58
2.1
2.1
") "7
•L, « ^
2.7
2.7
2.7
2.1
2.1
2.1
2.1
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.1
2.1
2.1
2.1
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
6
6
6
No. of
nozzles*
3
3
_}
3
3
1
1


1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
-1
1
1
2.7
2.7
2.7
Pressure
(kPa)
210
210
210
210
210
420
560
t20
560
420
560
*20
560
420
560
420
560
560
560
560
560
560
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
1
1
1
Nozzle
angle
in/fwd
(deg)
10/0
10/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
10/0
10/0
10/0
10/0
20/0
20/0
20/0
20/0
0/45
10/45
20/45
TBD
TBD
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
10/0
20/0
10/0
20/0
TBD
TBD
TBD
Length
of
boom
(m)
7
7
7
7
7
7
1
7
"7
7
7
7
7
7
7
7
7
7
7
7
7
7
12
12
12
12
12
12
12
12







         63

-------
               TABLES. u.S COAST GUARD SKIMMER/WATER 3ET TEST MATRIX (STATIONARY TEST)
CD
-C
Test
no.
1
2
3
4
5
6
7
8
9
10
ii
12
13
1*
15
16
17
18
19
20
21
22
23
24
Wave
(m)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.5HC
0.5HC
0.5HC
Q.5HC
0.3HC
0.3HC
0.3HC
0.3HC
Nozzle
ID No. of
(cm) nozzles
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 i
2.1 1
2.1 1
2.1 1
.2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
2.1 1
Water-
press.
(kPa)
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
Nozzle
tilt
angle
(de£)
0
22J4
it 5
0
0
22K
45
0
22ft
45
0
0
22ft
45
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
Nozzle
Angle
fwd
(deg)
0
0
0
22 ft
45
22Ji
45
0
0
0
22Yi
4,5
22ft
4.5
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
Slick
width
(m)
None
None
None
None
None
None
None
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Tow
speed
(kts)
0
0
0
0
0
0
0
4
4
4
4
4
4
4
6
6
4
4
6
6
4
4
6
6
    Notes:

    1.
    2.
    3.
Stationary tests had photos and movies taken through the underwater window.
Tow speed was simulated by swinging the water jet boom.
Oil slick was delivered on the water from a stationary bridge. Slick thickness was about 2 rnrn.

-------
         TABLE 9.  U.S. COAST GUARD SKIMMER/WATER JET TEST MATRIX (SLICK CONVERGENCE TESTS)
en

Test
no.
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Notes:
1.
2.
3.

Wave
(m)
0
0
0.5 HC
0.5 HC
0.5 HC
0.5 HC
0.5 HC
0.5 HC
0.5 HC
0.5 HC
0.5 x 15
0.5 x 15
0.5 x 15
0.5 x 15
0.5 x 15
0.5 x 15

Nozzle
ID
(cm)
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
• 2:1
2.1

No. of
nozzles
on one side
i
i
1
1
1
1
1
i
i
1
i
1
1
1
1
1

Water
press .
(kPa)
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
560
Nozzle
Tilt
angle
(deg) 	
TBD
TBD
0
0
0
• o
0
0
0
0
0
0
0
0
0
0
Nozzle
Angle
fwd.
TBD
TBD
0
0
45
45
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
Non-stationary testing.
Slick length 45 m.
Oil slick thickness 2 mm.
                                                                         Slick
                                                                         width
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
       Tow
      speed
 Length
of  boom
4
6
4
6
4
6
4
6
4
6
14
6
4
6
LI.
6
20
20
20
20
20
20
9
9
12
12
12
12
9
9
20
20

-------
flanges were welded at each end of the pipe sections. These allowed the sections to be
joined and separated easily.  With  a  rubber  gasket between  the  flanges  very  little
water leaked  even at  a  pressure of  700  kPa.   The  construction  proved  to be
lightweight, easy to handle, capable of holding the water pressure, and stiff enough for
easy  rigging and  consistent performance in waves.   This  design  was used for  the
stationary boom pivoting tests, some tow tests on the catamaran, and then was  stored
to be used on  the  U.S. Coast Guard's  ZRV skimmer when it  came to OHMSETT for
testing.

DISCUSSION OF RESULTS

       The results  obtained  from  earlier tests  were again proven by these series of
tests  (Table  10)—the  larger  the nozzle and 'the greater the pressure, the  better  the
performance.  Comparison of the  plots of slick movement using water jets from 1.25
to 2.66 cm ID bear this out clearly.

       The benefit  of angling the  jets  was also established in these tests.  By angling
the jet in  the direction of  the desired oil movement performance was increased on 7 rn
booms. Even an angle of ten degrees was beneficial (Figures  32 through 3k). The tests
only  included inwardly directed  angles up to  20 .  The reason for the increased
performance in the use of the horizontal  component  of force  of the  angled  water
stream to push the oil. The reduction of the amount of air entrained deeply by  not
having the jet vertical did not have an effect  on these tests since the objective was to
move the  oil  quickly—not to hold the oil in place after it had been moved. Using a 7 m
boom  (including nozzle fittings and swivel  joints at the vertical  stanchion) on  the
catamaran the slick had  to be  converged in 3.6 seconds at  four  knots.  The slick
holding potential  of  the  water jets was  not required  for  such a short interaction
interval.  The slick was moved further using a 12-m boom and the angling  of the jets
inward did not seem to consistently increase performance (Figures 35 and 36).

       The forward angle of the water  jets was not beneficial to performance (Figures
37 and 38).  The theory behind the forward angle was  to place the point of impact
further ahead of the skimmer, essentially increasing the length of the boom.  The  use
of a longer boom increased performance (Figures 35 and 36) but the water jet nozzle
needs  to be relatively close (approximately  1  m) to the point of impact to  perform
well.   By angling the jet forward the travel path of the water stream was increased
beyond the distance where the stream began to lose coherence.   Penetration and air
entrainment  was reduced and the  impact area  of the water  was increased.   The
horizontal force component of the water  stream was directed  forward,  which did  not
help to converge the slick.  At times the forward angled jet  did produce a dramatic
initial wave which rolled the oil away from the jet.  It appeared to "plow" the surface
of the water over  and give the oil a push off  to the side.   The plowing effect was
especially  noticeable  when  the  jet was  angled  forward and  inward  (Figure  39).
However, this initial push was not enough to make up for the loss in current usually
developed by the entrained air and the  set of rolling, breaking waves which a vertically
directed jet produced (Figures 35 and 36).

       The pitch of the catamaran in waves resulted in the worst performance by  the
angled water jets.  Vessel roll  and heave also caused  changes  in  impact point and
length of  travel of the water jets but the effects were not as dramatic as those caused
by pitch (Figure 40). Because the jets were extended over  6 m  beyond the bows of  the
                                         66

-------
                       TABLE 10. WATER 3ETS TEST RESULTS (SLICK CONVERGENCE TlISI'S).
en
-j
Boom
igt
(m)
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
Nozzle
I.D.
(cm)
1.25
1.25
1.25
1.25
1.25
1.25
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
1.6
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
Tow
speed
(kts)
it
4
it
4
^
it
14
It
It
It
tt
it
4
ft
it '
it
it
6
2

-------
                                             TABLE 10. (Continued)
01
CO
Boom
Igt
(m)
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
12
Nozzle
I.D.
(cm)
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
2.1
Tow
speed
(kts)
14
4
14
4
4
4
4
4
4
4
4
4
4
4 -
4
4
6
6
6
6
6
6
6
6
6
4
Press.
(kPa)
560
560
560
560
560
590
590
590
590
590
590
590
590
590
590
590
210
590
590
590
590
590
590
590
590
590
Nozzle
Angle
in/fwd
(deg)
10/0
10/0
10/0
20/0
20/0
10/0
10/0
10/0
0/45
0/45
10/45
20/45
20/45
20/45
45/45
45/45
0/0
0/45
10/45
10/45
20/45
20/45
20/45
20/45
45/45
0/0
Slick
thk
(mm)
2.2
2.1
2.1
2.1
2.1
1.6
2.1
3.0
2.1
2.1
2.1
2.0
3.0
2.1
2.9
3.0
3.1
2.0
3.1
3.1
3.1
2.9
2.9
2.1
2.9
2.1
No. of
nozzles
on one side
1
1
i
1
1
1
1
i
1
1
1
1
1
1
1
1
3
1
1
1
1
I
A
1
1
i
1
Slick
move
(m)
2.97
2.89
2 . 89
3 . 20
3,04
2.59
2,7't
2. 13
2,43
2.59
3.65
2.74
2 . it 3
2.7H
2.28
ind
7.13
i.A7
2Jl 3
1 .(,7
\ .52
2 . I 3
2.59
Ind
2. 13
3.12
Wave
(m)
C
c
C
c
c
c
c
c
c
c
'C
0.5 HC
0.5 HC
C
C
0.5 HC
C
C
c
c
c
c
0.5 HC
0.5 HC
C
C
Orig
width
(in)
4 . 26
<4 , 26
4 . 26
4 . 26
4.26
6.08
6.08
6.08
4.26
6.08
6.08
4.26
6.08
4 . 26
4.26
4 . 26
6.08
4.26
4.26
4.57
4.57
4.26
4.26
20
4.26
20
Final
width
(m)
1.29
4.41
4.41
1.06
1.21
3.50
3.35
3.96
1.82
3.50
2.43
1.52
3.65
1.52
1.98
Ind
3.96
2.89
1.82
2.89
3.04
2. 13
1.82
Ind
2.13
2.97
Test
no.
24
35
32
31
36
42
<*J
w
71
70
5-7
78
67
76
SO
82
39
72
5-8
S-9
5-10
77
79
66
81
49
                                                                         (Continued)

-------
TABLE 10. (Continued)
Boom
Igt
(m)
12
7
7
7
7
7
7
7
7
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
6
6
6
6
6
9
Nozzle
I.D.
(cm)
2.1
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.7
2.1
2.1
2.1
2.1
2.1
2.1
Tow
speed
(kts)
6
it.
4
4
it
4
it
t
6
2
4
it
4 .
it
'4
It
It
6
6
6
6
6
6
6
*
4
4
4
6
it
Press.
(kPa)
590
210
245
245
t2Q
420
420
490
490
180
180
180
• 180
180
490
490
490
180
180
180
180
490
490
490
590
590
590
590
590
590
Nozzle
Angle
in/fwd
(deg)
0/0
0/0
10/0
20/0
0/0
10/0
20/0
20/0
20/0
20/0
0/0
10/0
20/0
20/0
0/0
10/0
20/0
0/0
10/0
20/0
20/0
0/0
10/0
20/0
0/45
0/45
45/45
0.45
45/45
0/45
Slick
thk
(mm)
3.1
2.9
1.1
2.2
2.2
1.1
1.1
2.1
2.1
2.2
2.3
2.1
2.0
2.1
2.1
2.1
2.1
3.1
3.1
3.0
2.1
4.6
3.1
3.1
2.1
2.3
2.4
2.4
2.2
2.0
No. of
nozzles
on one side
1
1
i
1
1
1
1
1
1
1
1
i
I
1
i
i
i
1
i
1
1
1
1
i
i
i
i
i
i
i
i
Slick
move
(m)
2.43
J.67
2 . 1 3
I.R2
2.13
2.66
2.59
Ind
2.13
Ind
2.89
3.20
3.15
Ind
3.81
3.81
3 . 50
2.43
2.28
3.04
1.82
2 . 4 3
2. 59
2.X 9
2.7/*
1.82
2.28
2.13
2.43
2.28
Wave
(m)
C
C
C
C
C
C
C
C
C
0.5 Hi:
C
C
C
0.5 HC
C
C
C
C
C
C
0.5 HC
C
C
C
0.3 HC
0.6 HC
C
0.3 HC
C
C
Orig
width
(rn)
6.08
4 . 26
4 . 26
4.26
4 . 26
4 . 26
4 . 26
6.08
6.08
6. OS
6.08
6.08
6 . 08
6.08
6.08
6 . 08
6.08
6.08
6.08
6.08
6.08
6.08
6.08
6.08
4.57
4.57
4.57
4.57
4.57
4.57
Final
width
(m)
3.65
2.59
2.13
2.43
2.13
1.60
1.67
Ind
3.95
Ind
3.20
2.89
2.74
Ind
2.28
2.28
2.59
3.65
3.81
3.04
4 . 26
3,65
3.50
3 . 20
1.82
2.74
2.28
2.43
2.13
2.28
Test
no.
50
9
28
30
8
27
29
68
69
63
57
59
61
64
56
55
54
58
60
62
65
5J
52
53
18
i 7
15
19
16
20

-------
  C4.5
  K
  M
  0
     5

  M
  E   3
  N
  N

  M
  E
  T
  E
  R
  S
2.5


  2


 .5
       u
I-
                                            OR1ENTATION  OF WAI ER JET  i!07.ZLE
                                           h- 8/0 (ANGLE  IN/ANGLE FWiV)
                                           D- 18/8 (ANGLE IN/ANGLE ruf»
      0
       100
           200
                           300         400         580
                             WATER JET  PRESSURE  (KPa>
808
708
Figure 32.  Performance of a 1.25-cm ID  water jet at H  kt in calm water (oil  slick convergence test)
2.2-mm slick.

-------
             ' >•- -"•>,'•"  ' ,' • /r.~" fvii.•«*•"•• ,<
           ii'A :>••••".' ' '•.-£&$r *  .
           ^\-->^v\1iJi^'''-^>^
           ;  .; ' -, i • , .'tfi^Stf ~ \.  *

Figure  33.   An  inwardly directed nozzle  on a single water jet boom mounted ,
on the  OHMSETT catamaran.  Note  that the greatest portion  of current energy
is  directed in towards  the centerline of the system.
                                       71

-------
S    I
L   5 i
I    I
C4.5 j-
K

M   "
0
 ORIENTATION OF  WATER JET NOZZLE
A- 0/0  CANGLE IN/ANGLE  FWD)  -1 KTS
D- 10/0 CANSLE IN/ANGLE FWD) 4 KTS
0- 0/0  CANGLE IN/ANGLE  FWD)  >\ KTS, 3
                                                                      JETS
                                   0/0 CAN8LE  IN/ANGLE FWD) 6 KTS, 3  JETS
    M
    E
    N
J.
H
T
E
R
S
     r
       2
         u
     0.5
       0
                   200
                           300         400         500
                             WATER  JET PRESSURE (KPa)
                                   880
780
Figure  34.  Performance of a 1.6-cm ID water jet at 4 kt and 6  kt operating in cairn water   (oil slick
convergence test) 2 to  3-mm  slick.

-------
-•J
lA)
     r
s
L   b
1
C4.5 I-
0

E3'5
M
E   3
N

T2.5

I
N   2
      !_
           L
                      3 JETS, 2 KNOTS
                             A
                                         ORIENTATION OF  WATER JET  NOZZLE
                                         A-  8/0 CANSLE IN/ANGLE FWD.)
                                         0-  10/8 (ANGLE  IN/ANGLE FW[»
                                         0-  28/0 CANGLE  IN/ANGLE FWD)
                                         i~  0/45 CANGLE  IN/ANGLE FWD)
                                         0-  28/45 CANGLE IN/ANGLE  FWD)
                                         •-  45/45 CANGLE IN/ANGLE  FWD)
                                                                 O
                                                                 •r:.i

                                                                 •A
                                                                 A 12 METER  BOOH

                                                                   1C TEST
      T
      E
      R
      S
       0.5
                      280
                                                                 608
                                                                             700
                              388         488         580
                                WATER JET  PRESSURE CKPa>
Figure 35.  Performance of a 2.1-cm ID  water jet at 4  kt.  Oil slick of 2-3-mm  thickness, calm water,
7-m boom (oil  slick convergence test).   Note:  A harbor chop test at U kt, a calm water test  at 2 kt,
12-m boom test,  and  a test using three  jets were plotted for comparison.

-------
s
L
I
C
K
M
0
V
E
M
E
N
T
I
N
M
E
T
E
R
S
5

4.5

4

3.5


3

2.5

2
1 .5

!


    8.5 *-
       0
        88
                                ORIENTATION OF  WATER JET  NOZZLE
                                A- 0/0 CANGLE  IN/ANGLE FWD)
                                D- 0/45  CANGLE IN/ANGLE  FWD)
                                0- 10/45 CANGLE IN/ANGLE FWD?
                                i- 20/45 CANGLE IN/ANGLE FWD)
                                0- 45/45 CANGLE IN/ANGLE FWD3
                                                                  o
                                              12  METER BOOM'
                                                                       •1C  TEST
                        A 3 JETS
                                                O
                                                                 n
200
300         400         500
  WATER JET  PRESSURE  CKPcO
608
700
Figure  36.  Performance of a  2.1-cm ID water  jet at 6 kt operating on  a  7-m boom  in calm  water (oil
siick convergence test).  Note:  A  harbor chop test, a 12-m boom test and a multiple jet test were
plotted  for comparison, all with 2-3-mm slick.

-------
   I
   C4.5
   K

   M   «
   0
   N

   M
       3 *-
         j

     2.5 j-
                                ORIENTATION  OF  WATER JET NOZZLE
                               A-  8/8 CANSLE IN/ANGLE FWD)
                               D-  18/0 CANSLE IN/ANGLE FWD)
                               0-  20/0 CANGLE IN/ANGLE FWD)
                 0- —
                 D

                                                        \2 METER  BOON,CALM UATFR
                                               7 METER  BOOM..CALM WATER
     1.5h
         -
     0.5 h
       0
        \ 88
288
380         488        588
  WATER JET PRESSURE CKPa>
_i__~
 600
700
Figure 37.  Performance of a 2. 7-cm ID water jet at 4 kt on a 7-m and 12 m boom foil slick convergence
test),  2.3-m slick.

-------
  s
  [
     L
  C4.5 h
  K
M
0
V

H
E
N
T

I
N

M
E
T
E
R
S
     4 h
  3 (-


2.5 -


  2


\.5\-
   0,5
     8
     I	
     80
                                      ORIENTATION OF WATER JET NOZZLE
                                      A-  0/8 CANGLE IN/ANGLE  FWDD
                                      D-  10/0 CANGLE IN/ANGLE FWD)
                                      0-  28/8 CANGLE IN/ANGLE HUD)
                                                      4 KNOT TESTS,CALM  WATER
                                                      6  KNOT TESTS,CALM  WATER
                <>6 KNOT TEST, HARBOR CHOP
                  280
                          308        400         508
                            WATER JET PRESSURE  CKPa)
688
700
Figure 38.   Performance of a 2.7-cm ID water jet at 4 kt and 6 kt operating on a 12-m boom  (oil
slick convergence test) .

-------
           —^^^8
                     -»*,*•'»«: -"S*."! **.• >T
                                        .' ***.
Figure 39.  Water jet angled forward and inward during a clam water test.
    (Note the rolling wave produced at the impact point).
                           77

-------
                                     • £2 r
                       X"'
                                                 ,-4,
                        ':'- vr •••
                       .. • SL i'., ;•
                                                      }
                                                      *.
                                             :%;^Sf|
                                                    ^ <-<^J* -  £L,"wB*1"

                                                 •%1& ..i:.
Figure  40.  Water jet angled  forward and inward during a wave test.   (Note

the impact point traveling far forward and onto the ofl  slfck due to  the rear

pitch of the catamaran).
                                     78

-------
nulls, the amplitude ol piich was increased at the water jet nozzles.  When the nozzles
were raised upward during a stern pitch of the  catamaran the point of impact moved
dramatically forward from its  calm water  or  Intended  position.   When  the jet  was
angled at 45  Inward and 45° forward, the water sprayed over the oil  slick entraining
oil and  caused an  irregularly-shaped slick.  This also lengthened the path of travel of
the water stream and thus decreased the effectiveness of the jet.  When  a bow pitch
was  experienced  the  impact  point was  brought  back  across the  slick  to  directly
beneath  the nozzles. During some  wave tests the performance of  the water jet  was
indetenninant because the resulting  slick was so irregular.
                                                 -o
       One of the most important finds of this test program was that angling the water
            s  not beneficial when operating in wave c
            I, and heave.  Since  such conditions are the norm in  oil spill  recovery a
general operation rule can be made—point the jets straight down into the water.  This
simplifies the construction and use of the water jets.  Those of  us in the relatively
pristine world of test tanks  are  prone to strive for the optimum  angle and operating
pressures  to tweak the 'ast bit of  r.>erforrnance  from  the system.  Those  neopie who
work in the usually oil-bisckenc-c and uncomfortable field operation? are prone to use a
simple, dependable, and rugged  deployment  of  a system.  Their attention is often
called  for in  areas  of  personnel safety and  labor-intensive duties.  They have little
time to determine if the pitch of the skimmer has changed sufficiently over the last 15
minutes to warrant a change in water jet impingement angle.  A system which  has the
best chances of performing well when used in its simpliest configuration  will probably
be looked upon favorably by field operators.

       Three water  jets in tandern, spaced about 1 m apart, performed  as well as or
better  than one water jet at the same pressure (Figures 34 and 35). But by using more
than one  jet,  a significant drop  in  available  water jet pressure was experienced.  In
some instances an increase in pressure of one water jet could equal the performance of
the three  jets with reduced  pressure.   A possible  drawback  to using the tandem
arrangement at high tow speed was that  the wave train produced by the three jets
persisted longer than that produced by a single jet (Figure 41).  Although the breaking
waves move oil, they also entrain it slightly below the surface.  The entrained oil may
not have  sufficient  time to  rise if  the breaking  wave persists into  the  mouth of the
skimmer.

       The tests conducted with the catamaran  stationary and pivoting the water jet
boom  in an arc provided an  interesting view of oil slick movement mechanisms and
entrainment characteristics of a water jet. From the underwater  window the point of
view of a particle  behind and beneath  a water jet  was  available.  The vertically
directed  jets  appeared to  entrain  the   most "air and  to a  greater depth, which
maintained the surface current caused  by the rising air bubbles for the longest period
of' time.  The angled jet moved the oil the fastest but also entrained the most oil.
                                        79

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                   f ''"'^V' v."* > t; :1 ''-V •'*. v.':1!-- . ,'T|C!"  '•"
Figure 41.   Tandem water jets during a tow  test.  (Note the bow wave of
the second  water jet coincided with the second wave of the first  jet).
                                      80

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                                   SECTION

                WAT
INTRODUCTION

       Water jets on  Individual  floats  have the  potential to  solve many  problems
associated with oil spill recovery operations.   Equipment deployment,  wave effects,
ship traffic Interference, and fire are some of the hindrances  which could  be coped
     bv proper  use of water iets on floats.
       Equipment deployment—an oil barge offloading site is often required to ring the
barge with a fabric boom before oil can be offloaded.  Obviously the boom cannot be in
place before the  barge arrives  and therefore a trained boom deployment/retrieval
team must be employed after the barge arrives  and before it  leaves.  A  water jet
system could be used In place of a fabric boom.  Water jets on floats could be supplied
by submerged hoses, can be left  in position, and the only action required  would be to
start a purnp and turn a valve or two. The water jet floats could be bumped aside or
even momentarily submerged by the barge and tug as they arrive or leave.

       Wave effects—when using conventional  fabric booms to converge an  oil slick
into a skimmer the reflection  of small waves between the booms cause problems. The
waves are  finally concentrated in front of the skimmer inlet causing oil entrainrnent,
oil loss from the booms, and a decrease in skimmer performance. A series of water jet
floats  used in  place of the  booms  (Figure 42) could allow  waves  to pass  and  yet
converge the oil.

       Ship traffic interference—if an oil spill occured and  oil retaining had to  be
conducted  in  a  ship channel the  damage caused  by a  wayward  vessel  could  be
minimized if it passed into the retained oil slick through a water jet float line. Many a
fabric boom busy retaining oil has been destroyed by errant ship traffic.  The  result is
a loss of oil retention until the vessel is removed and the boom  repaired.

       Fire—the possibility of damage to water jet floats by  a  fire is less  than to a
conventional fabric boom since the floats and jets can be made from steel.  Since the
action of the water jets maintain the oil away from the equipment, the flames  may not
even reach the water jet floats to endanger them.

       Possibilities such as these prompted a series of tests to  be  conducted  at
OHMSETT which  would determine  the feasibility  of using water jets on  Individual
floats to control an oil slick.  The tests were aimed at the use of such floats in a fast
current situation.  This chapter presents the results of those tests.
                                        81

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                         1.2 x 2.^-m plywood
CD
NJ
                                                                          / Water let noszle
       Water supply hose
       and tow line
                                 Inflatable bags tied to the
                                 plywood.
                            Figure 42.   Isometric drawing of a  water jet float.

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CONCLUSION'S

       The use of water  jets mounted on  individual  floats to control an oil  slick is
feasible.   However,  there  are  problems which must be solved before  the  concept
becomes practical for field  use.

       The construction of water jet floats  can be done using plywood, standard pip' r
material, and suitable floatation (e.g., inflatable bags, steel drums, logs).

       Water jet  floats allow waves normally reflected by converv:  -.al fabric booms
to pass whije retaining an oi! slick.                                ^*

       Maintaining  the  individual floats  in a predesigned orientation  and formation
while towing proved difficult. Floats drifted behind one another due to the fluid drag.
Before proper counterweights were  used  to counter the forward  pitching force of  the
supply hose, the floats would occasionally submerge at their bow and flip over.

 RECOMMENDATIONS

       Since only one side of a converging boom system was tested the performance of
a complete oil slick converging system can  only be extrapolated.  Another test series
should be conducted  using  at least  three floats per side.  The proper  orientation and
relative position of the floats should be easier to  maintain because tie lines could be
used across the sweep width.  They would serve  to stabilize each  float by using its
mirror image to supply a corrective force to balance the drag forces on the floats.

       Three prototype permanent water jet  floats  could be built  and placed in  the
OHMSETT  tank behind the wave generator.  They would serve to keep oil from  gaining
entrance behind the  flaps and becoming  emulsified.  The floats would also show  the
possible problems which could develop with the water jet  floats when used in a rough
environment.

       A water jet float  more suitable for towing in a desired pattern with other floats
should be designed and tested.  Perhaps a circular float such as a tire inner tube would
be advantageous since a  slight rotation of the system would not cause  a change in  the
resultant drag forces. A rudder skeg on the  underside of the type of floats  used in
these tests should also be investigated.

TEST DESCRIPTION

Test Equipment

       The water jet  floats (Figure ^2) were  constructed from inflatable fabric bags
lashed by rope to a 1.2 x 2.4 m piece of plywood 1.3 cm thick.  A base  and brace was
bolted to the top of  the plywood to support the 2.5 cm  ID piping.   A reducing elbow
was  mounted beneath the  plywood  and inbetween the floats  to connect  the  7.6  cm
water  supply hose to  the steel piping.  A 30  cm long, 2.1 cm ID pipe was used as  the
nozzle. The nozzle exit was directed vertically downward and set at a mean height of
0.6 m from the water's surface.  The 7.6 cm ID flexible water supply hoses doubled as
tow cables for the floats. The floats were held in their relative positions by 1 cm rope
tied  to the auxiliary,  video, and main bridges (Figure ty3 and tyty). Pressure gauges were


                                         83

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                         Direction  of  tow
                         	IT:-.

J i J1.
  I;
 JL .^.
                                             Wain
                           Main
                           Bridge
                                         2 Water supply hoses..
1  Test engineer
2  Test director
3  Oil distributor
U  Water pump operator
5  Photographer
6  Control  room operator*
7  VDU operator*
8  Filter operator*
*Not shown
                                      \
                                                    Water
                                                    Jet
                                                    Floats
      Figure  43.  Test  set up for  water jet float program.

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Figure 44.  Water jet floats under tow diverting an oil  slick.

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installed in the  water supply lines on  the main bridge  In advance of the 7.6 crn nose
connections.  To prevent the floats from nosing down in  front due to the weight and
drag force of the 7.6 cm supply hose,  weights were placed on the floats and over the
rear to counter the hose forces.

      Towards the  end of  the test program, an independent water  jet fjoat was built.
A  high  pressure (420 kPa) gasoline  engine  water pump was mounted on  a small
OHMSETT catamaran work boat (Figure 45) and towed  from the main bridge via a 1.3
crn rope.

      The slanting pattern of floats  across  the tank  was designed  to  divert the oil
slick across the  tank  in incremental steps.  The floats  were separated by 15 m  down
the tank and  L8 m across the tank. Oil was distributed from the main bridge in a slick
initially 4.5 m wide and 3 mm thick.

Test Plan
      A test matrix  was designed for  these  tests (TabJe 11) in conjunction  with the
U.S. EPA to  investigate the effects  that tow speed and waves  nave upon water  jet
float performance.  Due to the nature of prototype testing, not all of the  proposed
tests could be conducted.

      All tests  were conducted according to the test plan presented  below in order
that the tests could be compared to one another.

Test Procedures

      1.     The water jet floats were positioned in the test tank.

      2.     The proper test number was placed in the display board.

      3.     Oil distribution was set  to deliver the desired slick thickness for the tow
             speed.

      4.     If  the test was to involve a harbor chop  wave, the wave generator was
             started and the waves allowed to build up for 10 minutes.

      5.     The photo/video department took their positions.

      6.     Water to  the  water  jet floats  was turned  on and the desired  pressure
             obtained.

      7.     The oil  skimming booms  beneath  the auxiliary bridge and main bridge
             were raised.

      8.     The tow was  begun  by bringing the bridges up to the designated  tow
             speed.

      9.     Oil distribution was started and continued  for two hundred feet of tow.
                                        86

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              c

                      "
                                         *>/*\xf?V:%il?r|:4i;J11
                                                    1
Figure  45.   Water  jet workboat  with gasoline pump.
                          87

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TABLE 11.  WATER 3ET FU
TEST MATRIX
Test
no.
1
2
3
i
H
sr
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
20
21
22
23
2*
25
26
27

28

29

30

31

32

Tow
speed
(kts)
0-4
4-6
2
t
6
2
4
6
2
^T
b
2
4
6
2
4
6
2

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       10.    After oil  distribution  \\ as corr.'plcted  the  bridges were slowed to a halt
             and the skimming booms Jc\vered.

       11.    If a harbor chop wave was used during trie-test, time was allowed for the
             waves  to  sufficiently  subside  to  alJow  for oil skimming by the  bridge
             booms.

       12.    The bridges were returned to the  north end of the towing tank at 0.5 kts.
             The oil on the surface was thus cleared so not to interfere  with  the next
             test.

       Results of the tests were recorded  by still and movie photography and  on video
tape.

DISCUSSION OF RESULTS

       Tne water jet fioat concept performed well but problems with T.ainiaining fjoat
position and stability in a diversionary mode of operation  must be  solved before the
floats  can  be  considered a viable alternative to fabric booms.   An advantage to the
water  jet  float system over the fabric  boom  is  the ease  of  relocating  a  poorly
positioned  fioat to  divert  oil rather than  realigning an  entire boom  section while
fighting the current.  The floats in the tests were positioned 15  m apart measuring  in
the longitudinal axis of  the tank and 1.8 m in the transverse axis.  These positions were
selected for tests  using tow speeds of from  4 to 6  kts.  The spacing seemed  to work
well for the ^ kts tests  but fell a  little short for the 6 kts  tests.  The oil slick was not
diverted the entire 1.8 m before the following float contacted the oil slick. However,
for 2 kt tests it appeared  that the transverse spacing could have been increased  to
about 3 m. To move a water jet over 1.2 meters would require little effort  if the float
was positioned by a bridle to two  anchor points upstream and on either side of it.  The
draft of the floats was about 5 cm with a projected cross current length of 0.5  m.  This
resulted in a projected  area of about  0.025  m^.  A fabric  boom with a draft  of 0.5  m
and a projected length of 3 m would have  a final projected area  of 1.5 m*.  The force
required to overcome the fluid drag on the  boom would be 60 times that to move the
water jet float.  Using FzpAv^Cf} as the equation for drag force  and letting Cj} = 1.5.
The  force  to move the  fabric boom in a  current of  2  knots would be about  118 kg.
While the force required to move  the  water  jet float would be about 2 kg. Problems
with ropes stretching and  breaking, knots  giving  way or  anchors  moving would be
greatly reduced using water jet floats.

       The structure of the water jet floats used in the test program was  dictated by
the materials on hand or readily available.  The problems  of front end  submergence,
capsizing, and position  drift could be solved by proper float design and water  supply
hose location.   The small  work boat  which had the gasoline  driven  pump  onboard
experienced no stability problems.  Proper  rigging  or the use of a  rudder skeg could
eliminate any position drift problem.  If two sets of water  jet floats are used  in front
of a skimmer (Figure 46), the tie lines and drag force of the skimmer should be able  to
keep the floats in position.

       The water jet floats performed as  well in harbor chop waves as in calm  water.
The vertically directed  jets maintained their approximate point of impact  despite the
roll, pitch, and heave of the buoyant floats.


                                       89

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                           Direction  of Tow
                                 I Main
                                 1 Bridge
       Water
       supply
       hose/tow
       ine
                                               Oil  Skimmer with
                                               water jet  booms
Figure 46.   Double-sided water jet boom used in conjunction  with a  skimmer.

                                     90

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      The use of a high pressure gasoline-engine pump to power a water jet instead of
using a  hose  from the bridge pump seemed to have more advantages than disadvan-
tages during  the  tank tests.  During field operations logistic problems may outweigh
those advantages. The need for the heavy water supply hose was eliminated with an
individual pump on the float. Towing and maintaining float position and stability was
made easier.  In the field there would be no hose to be  deployed, rammed, ruptured, or
Jos*.  The drawback  is the maintenance of the pump so that  it performs continuously.
A large  gasoline supply can be included on the float, but it must be refilled eventually.
The pump inlet may  become clogged by debris or the machinery may break down, thus
leaving  a breach  in  the oil spreading  defenses.  However, a more  reliable electric-
driven pump  mounted on  shore  or a large vessel would necessitate  using the supply
hose.
                                         91

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                                 REFERENCES
i.     Roberts, A.C.   Using Fire Streams  with  a Self-propelled Oil Spill Skimmer.
      EPA-R2-113, U.S. Environmental Protection Agency, Cincinnati. Ohio, 1973.

2.     Katz. Bernard anc- R. Cross.  Use ol Fire Streams to Control Floating Oil, EPA-
      R2-73-113, U.S. Environmental Protection Agency, Cincinnati, Ohio, 1973.

3.     Graham,  D.J.,  R.W.  Urban,  M.K. Breslin,  and  M.G. Johnson.   OHMSETT
      Evaluation Tests;  Three Oil Skirn'Tiers anc' a Water jet Herder, EPA-SOO/2-SO-
      020. U.S. Environmental Protection Agency, Cincinnati, Ohio, 198C.

4.     Breslin,  M.K.   Performance  Tests  of  High  Speed ZRV  Oil  Skimmer,  U.S.
      Department of  Transportation,  U.S.  Coast  Guard,  Office of  Research and
      Development, Report No. DOT-CG-842702-A,  Washington, D.C., 1980.

5.     Hires,  R.I., D.T. Valentine and  3.P. Breslin.  Literature  Search on Plunging
      Water 3ets for Oil Spill Containment, 3uly 1979, unpublished report.

6,     Valentine D.T. and R.I. Hires.  Theoretical Analysis to Predict the Performance
      of a Penetrating Water  3et  in  Controlling Oil Spills, 3uly 1979, unpublished
      report.

7.    . Breslin,  3.P.    Flow  Pattern  Induced by  a  Vertical  Translating Water  3et
      Penetrating the  Water Surface, 3uly 1979, unpublished report.
                                        92

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                                 APPENDIX A
            UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
               :•'">-", '-> J'~ T -n'frf, f "^.""^'-i:
               i^s-J.^.^ * ">;;**, 4 P1-^
       The U.S. Environmental Protection Agency operates  the  Oil  and Hazardous
Materials Simulated Environmental Test Tank (OHMSETT) located in Leonardo, New
Jersey.  This facility provides an environmentally safe place to conduct testing and
development of  devices  and  techniques for the" control  and clean-up  of oil  and
hazardous material spills.

       The primary feature of the facility is a  pile-supported, concrete tank with a
water  surface  203 meters long by  20 meters wide and  with a water  depth of 2.4
meters.  The tank can  be filled with fresh or salt water.  The tank  is spanned by a
bridge capable of exerting a  horizontal  force  up  to 151  kilonewtor.s  while towing
floating equipment at speeds to 3.3 meters/second (6.5 knots) for at least ^0 seconds.
Slower speeds  yield longer test  runs.   The towing bridge is equipped  to lay oil or
hazardous materials on the surface of the water several meters ahead  of the device
being tested, so  that reproducible thicknesses and widths of  the  test  slicks can be
achieved with minimum interference by wind.

                                        93

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a
       The principal systems of  the :ank include a wave generator,  a beach, and
filter system.  The wave generator  and absorber  beach can produce regular waves to
0.6 rneter high and to 45 meters  long, as well as a series of 0.7 meters high reflecting,
complex' waves meant to simulate the  water surface of a harbor.  The tank water  is
clarified by recirculation  through a 410 cubic meter/hour diatomaceous earth filter
system to permit full use of a sophisticated underwater photography and video imagery
system  and to remove  the  hydrocarbons that enter the tank water  as a result of
testing.  The towing bridge has a built-in oil barrier which is used to  skim  oil to the
North end of the tank for cleanup and recycling.

       When  the  tank must  be  emptied  for maintenance purposes, the entire water
volume of 9800 cubic meters is filtered and  treated until it meets all applicable State
and Federal water  quality standards before  being discharged.  Additional specialized
treatment may be used whenever hazardous materials are used for tests.

       Testing at the facility is served  from  a 650 square meters building adjacent to
the tank.  This building houses  offices, a  quality control laboratory  (which  is very
important since test fluids and tank water are both recycled), a small  machine shop,
and an equipment preparation area.

       This  government-owned, contractor-operated facility  is available for  testing
purposes on a cost-reimbursable basis.  The operating contractor, Mason  & Hanger-
Silas  Mason  Co.,  Inc.,  provides a permanent staff  of eighteen multi-disciplinary
personnel.  The U.S. Environmental  Protection Agency provides expertise in the area
of spill control technology and overall project direction.

For additional information, contact:  Richard A. Griffiths, OHMSETT Project Officer,
U.S. Environmental Protection  Agency, Research  and Development,  MERL,  Edison,
New 3ersey 08837.  Telephone: 201-321-6629.

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                                 APPENDIX B

                          OHMSETT OIL PROPERTIES
      OHMShTT test fluids (light, medium, and heavy oils) are sampled and analyzed
several times during the  process of using them in testing. The steps and analyses are
detailed below. Some test programs do not involve all sample procedures and sampling
frequencies are many times different.
      Test fluids in  bridge storage tanks are sampled at least once daily.  Some test
programs require more frequent sampling when test fluids are pumped onto the bridge
more than once a day.  Samples are analyzed for the properties detailed in Table B-l.

                         TABLE B-l. OIL PROPERTIES
Sample
Prqgerty_

Viscosity
Surface
Tensions
Interfacial
Tension w/
Tank Water
Specific
Gravity
Temp
Method °C

ASTM D-88 Room
ASTM D-341 and
ASTM D-2161 75
ASTM D-971 Room
ASTM D-971 Room
ASTM D-287 Room
ASTM D-1298
Acceptable Ra:
Outpjjt

Vise. vs.
Temp Chart
dynes/cm
dynes/cm
Sp.Gr.
@60/60
Light
cSt
3-10
@25°C
24 to 34
@25°C
26 to 32
@25°C
0.83-0.91
Medium
cSt
100-300
@25°C
24 to 34
@25°C
26 to 32
(925°C
0.90-0.94
Qfi£
Heavy
cSt
500-2000
@25°C
24 to 34
@25°C
26 to 32
@250C
0.94-0.97
Bottom Solids  ASTM D-96
and Water     ASTM D-1796
Room  % BS&W
less than 1%
                                       95

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TECHNICAL REPORT DATA
[Plc'ase read Instructions on the reverse before completing)
\
4.
7.
9
12
15
REPORT NO. 2.
TITLE ANOSUBTITLE
The Use of Coherent Water Jets to Control Oil Soills
AUTHOR(S)
Michael K. Breslin
PERFORMING ORGANIZATION NAME AND ADDRESS
Mason & Hanger-Silas Mason Co., Inc.
P.O. Box 11?
Leonardo, NJ 07737
. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH H5268
3. RECIPIENT'S ACCESSION-NO.
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO
10. PROGRAM ELEMENT NO.
INE826
11. CONTRACT/GRANT NO.
68-03-26H2
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/1 If
. SUPPLEMENTARY NOTES
John S. Farlow, Project Officer (201-321-6631)

16. ABSTRACT
The ability of coherent water streams to induce a surface current in water and
thus control a floating oil slick was examined at the U.S. Environmental Protection
Agency's (USEPA) Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT)
The objective of the tests was to evaluate coherent water streams as an alternative to
fabric booms and water sprays in concentrating, diverting, and containing oil slicks.
The water Jets were constructed from standard pipe fittings and supplied with
water from common centrifugal water pumps. They were mounted on the main towing
bridge, built into small floats that were angled across the direction of tow, and
extended from the bows of a catamaran. Currents of up to six knots were induced by
towing the water jets from the main bridge.
The tests showed that coherent jets could induce a significant surface current
and move an oil slick with little oil entrainment. The non -breaking waves produced
by the OHMSETT wave generator did not greatly affect performance except where the jet
nozzels were cantilevered off the front of the catamaran. The best position for the
untended water jets tested was to be vertically directed at the surface of the water
with the outlet O.^f to 1.0 meters above the surface. The vertical component of a
coherent water stream was found to be as useful, if not more so, as the horizonal
component. A water jet supplied by a 30 kw electric motor/centrifugal pump system
oerformed better than a source of compressed air (210 kPA) extended 0.6 m below the
surface supplied by a 50 kw gasoline- driven air compressor.
17
a.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS b.lDENTlFIERS/OPEN ENDED TERMS
Performance Tests Spilled Oil Cleanup
Skimmers Protected Waters
Water Pollution Coastal Waters
Oil Oil Booms
13
DISTRIBUTION STATEMENT 19. SECURITY CLASS (This Report/
Rclca-c to Public Unclassified
nuj-oa^t- bu ruuxxu 20. SECURITY CLASS ^rw* page;
Unclassified

c. COSATI Field/Group

21. NO. OF PAGES
107
22. PRICE
EPA Form 2220-1 (9-73)

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