&EPA
United States
Environmental Protection
Agency
Industrial Environmental Research EPA-600/2-78-186
Laboratory August 1978
Cincinnati OH 45268
Research and Development
Boom Configuration
Tests for Calm-Water,
Medium-Current
Oil Spill Diversion
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-186
August 1978
BOOM CONFIGURATION TESTS FOR CALM-WATER, MEDIUM-CURRENT
OIL SPILL DIVERSION
by
Michael K. Breslin
Mason & Hanger-Silas Mason Co., Inc.
Leonardo, New Jersey 07737
Contract No. 68-03-0490
Project Officer
John S. Farlow
Oil and Hazardous Material Spills Branch
Industrial Environmental Research Laboratory
Edison, New Jersey 08817
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory, U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessari-
ly reflect the views and policies of the U.S. Environmental Protection
Agency, nor does mention of trade names or commercial products consti-
tute endorsement or recommendation for use.
ii
-------
FOREWORD
When energy and material resources are extracted, processed, con-
verted, and used, the related pollutional impacts on our environment and
even on our health often require that new and increasingly more efficient
pollution control methods be used. The Industrial Environmental Research
Laboratory - Cincinnati (lERL-Ci) assists in developing and demonstrating
new and improved methodologies that will meet these needs both efficiently
and economically.
This report describes the performance of various deployment con-
figurations of standard booms in medium-current inland streams. The
more promising ones indicate that a considerable improvement in per-
formance can be achieved with relatively little additional effort.
These techniques will be of interest to all those interested in cleaning
up oil spills in coastal and inland waters. Further information may be
obtained through the Resource Extraction and Handling Division, Oil and
Hazardous Materials Spills Branch, Edison, New Jersey.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
ill
-------
ABSTRACT
The purpose of this test program was to determine the effects of
boom angle, length, and rigging configuration on diversion of oil floating
on moving streams.
The B.F. Goodrich Seaboom was chosen for the program because of its
availability, durability, and stability. It was rigged in different
diversionary modes and towed into an oil slick at the U.S. Environmental
Protection Agency's (USEPA) Oil and Hazardous Materials Simulated Environ-
mental Test Tank (OHMSETT) test facility at various speeds, until
critical stability speed was attained. Boom performance was recorded on
photographs, video tapes, and observer notes. Results were evaluated in
terms of the percentage of oil lost beneath the boom and away from the
rear of the boom. A "nozzle-shaped" boom configuration achieved the
best diversion at tow speeds examined above 1.0 m/s. Different exits
from the nozzle configuration were investigated to find which one released
the oil with the least amount of entrainment and spreading. A straight
exit with tapered ends worked best. Tests were conducted in accordance
with a test matrix developed by the U.S. Environmental Protection Agency.
This report was submitted in fulfillment of Contract No. 68-03-
0490, Job Order No. 33, by Mason & Hanger-Silas Mason Co., Inc., Leonardo,
New Jersey, under the sponsorship of the U.S. Environmental Protection
Agency. This report covers a period from March 28 to April 5, 1977;
from April 11 to April 15, 1977; and from September 23 to September 30,
1977, when the work was completed.
iv
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CONTENTS
Foreword ill
Abstract iv
Figures vi
Tables vii
Abbreviations and Symbols viii
List of Conversions ix
Acknowledgment x
1 Introduction and Objectives 1
2 Conclusions and Recommendations 2
3 Test Apparatus Description A
4 Test Plan and Procedures 8
5 Discussion of Results 21
References 32
Appendices
A. Facility Description 33
B. Diversionary Boom Length vs. Angle Comparison 35
v
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FIGURES
Number Page
1 Nozzle configuration showing main bridge tow points
and oil distribution points 4
2 Exit of 20° "V" configuration showing auxiliary
bridge tow points 5
3 Tow back device attached to trailing end of
diversionary boom 5
4 General test set-up and personnel placement during
testing 9
5 Test set-up for 32° single diversionary boom 10
6 Test set-up for 20° single diversionary boom 11
7 Test set-up for 20° double diversionary or "V" boom con-
figuration 12
8 Test set-up for the parabolic boom nozzle configuration . . 13
9 Test set-up for "belled" exit nozzle boom configuration . . 14
10 Test set-up for constricted throat and "belled" exit
nozzle configuration 15
11 Test set-up for the parabolic nozzle configuration with
the straight, lifted exit 16
12 Test set-up for parabolic nozzle configuration with
parabolic exit 17
13 Test set-up for parabolic nozzle configuration with
quarter-circle exit 18
14 Design of parabolic nozzle configuration 20
15 Performance of B.F. Goodrich 18 PFX boom (32° angle,
diversionary mode 28.5 m long) 22
16 Performance of B.F. Goodrich 18 PFX boom (20° angle,
diversionary mode 21.4 m long) 23
17 Performance of B.F. Goodrich 18 PFX boom (20° "V" con-
figuration, 14.3 m on each side) 24
18 Performance of B.F. Goodrich 18 PFX boom (parabolic
nozzle configuration, 14.3 m on each side) 25
vi
-------
TABLES
Number Page
1 Single Diversionary Boom Test Results 26
2 Double Diversionary Boom ("V") Test Results 28
3 Double Diversionary (Nozzle) Boom Test Results .... 29
vii
-------
ABBREVIATIONS AND SYMBOLS
ABBREVIATIONS
C —Centigrade
cm —centimetre
deg —degree
F —Fahrenheit
kg —kilogram
m —metre
min —minute
mm —millimetre
N —Newton
s —second
SYMBOLS
0 —degree
0 —angle between boom and centerline of tank
% —percent
x —distance from boom exit parallel to the centerline of tank
y —distance from centerline of boom
dy/dx —slope of parabolic boom
viii
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METRIC TO ENGLISH
LIST OF CONVERSIONS
To convert from
Celsius
joule
joule
kilogram
metre
metre
metre2
metre2
metre3
metre3
metre/second
metre/second
metre2/second
metre3/second
metre3/second
newton
watt
ENGLISH TO METRIC
centistoke
degree Fahrenheit
erg
foot
foot2
foot/minute
foot3/minute
foot-pound-force
gallon (U.S. liquid)
gallon (U.S. liquid)/
minute
horsepower (550 ft
Ibf/s)
inch
inch2
knot (international)
litre
pound-force (Ibf avoir)
pound-mass (Ibm avoir)
to
degree Fahrenheit
erg
foot-pound-force
pound-mass (Ibm avoir)
foot
inch
foot2
inch2
gallon (U.S. liquid)
litre
foot/minute
knot
centistoke
foot3/minute
gallon (U.S. liquid)/minute
pound-force (Ibf avoir)
horsepower (550 ft Ibf/s)
metre2/second
Celsius
joule
metre
metre2
metre/second
metre3/second
joule
metre3
metre3/second
watt
metre
metre2
metre/second
metre3
newton
kilogram
Multiply by
1.000
7.374
2.205
3.
3.
1.
1.
2,
1,
1,
1,
1,
281
937
076
549
642
000
969
944
000
2.119
1.
2.
587
248
1.341
;tp-32)/1.8
E+07
E-01
E+00
E+00
E+01
E+01
E+03
E+02
E+03
E+02
E+00
E+06
E+03
E+04
E-01
E-03
1.000 E-06
tc = (tF-32)/1.8
1.
3.
9.
5.
.000 E-07
,048 E-01
,290 E-02
,080 E-03
4.719 E-04
1.356 E+00
3.785 E-03
6.309 E-05
7.
2.
457
540
6.452
,144
,000
,448
4.535
E+02
E-02
E-04
E-01
E-03
E+00
E-01
ix
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ACKNOWLEDGMENT
fo
provided
for his suggestions in the ,,.«
efforts ofSfll the technicians
greatly appreciated.
, *
is acknowledged
technl^e8' The
the testing program are
-------
SECTION 1
INTRODUCTION AND OBJECTIVES
Oils to meet our growing energy and lubrication needs are being
handled in increasing amounts and variety. The potential for accidental
discharge of these materials poses a serious threat to the welfare of
the general public and the environment. Since such spills are not
likely to cease (1), effective methods for dealing with oil spills must
be developed. Such is the purpose of these tests conducted at the U.S.
Environmental Protection Agency's (USEPA) Oil and Hazardous Materials
Simulated Environmental Test Tank (OHMSETT). See Appendix A.
Satisfactory diversion, containment, and cleanup of oil spills is
still in the development stages even on calm, inland waters. Because of
the relative inexperience of many people engaged in oil spill reponse,
the effective use of booms and certain limits of their capability and
rigging must be determined and publicized. Accordingly, these tests
were designed to find the most effective use of conventional flat-plate
booms (usually, the only kind available) in spill situations where the
water current exceeds 0.5 m/s. In streams the current speed generally
increases with distance from shore; if a boom can be rigged so as to
move the oil into a confined area in a low current region, the spill can
then be picked up by conventional means. If a high current skimming
device is available, the boom could also be used to concentrate the oil
in front of the device.
This USEPA test program was undertaken to obtain vital data needed
to begin standardization of boom use in medium current situations and to
lay the groundwork for further innovative study.
-------
SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
The boom configurations described here were rigged with the boom at
rest with respect to the OHMSETT tank water. The boom was then towed
through the tank water to simulate a current. In the field, the boom
must be rigged in a current, a more difficult situation. Any field use
of the boom configurations shown in this report will go far more smoothly
if they can be planned and practiced before an oil spill occurs.
If a straight diversionary boom is used to divert oil, parachute
mooring lines are necessary. The lines should be of small diameter to
avoid generating standing waves and thus entraining oil. Small cusps
form in the boom at the points of attachment and cause some shedding,
but not as much as the drastic cusp at the trailing end of a boom without
parachute lines. The lines also stabilize the boom, and permit higher
speeds before stability failure (e.g., boom diving or planing) occurs.
The angle of the boom to the current directly affects performance.
The more perpendicular to the current the boom stands, the lower the
speed at which oil loss and boom stability failure occur. When the
perpendicular component of current against a diversionary boom approaches
0.51 m/s, oil shedding increases dramatically.
Few vortices formed along the boom skirt in any configuration. Oil
losses were predominantly due to the shearing action of the water on the
oil/water interface (shedding). Not all of the oil which passed beneath
the boom skirt was lost. The horizontal vortical action of the water
passing beneath the skirt drew much of the entrained oil into a quiescent
zone behind the boom. The same vortical action kept the oil from leaving
the rear of the boom. The result was that the oil traveled down behind
the boom and rejoined the unentrained oil at the exit.
The straight exit from the nozzle configuration, with the rear
of the boom sections lifted from the water, proved to be the best shape
of those tested. The exiting oil slick remained the width of the exit
for about ten seconds before beginning to spread. Entrainment was
minimal due to the absence of turns or sharp edges that would have
caused turbulence. Even with the boom skirt tied up around the floata-
tion, the parabolic and quarter-circle exits created too much turbulence
for the oil to leave the boom without clinging to the floatation or
being entrained.
-------
Oil losses Increased downstream along the boom when a straight
diversionary configuration was used. Nozzle-shaped configurations
appear promising since less entrainment and fewer standing vortices
resulted at the exit. At 1.67 m/s, the nozzle configuration lost only
7% of the encountered oil, while the 20° "V" configuration lost 15%.
The crucial area of the nozzle shape is the leading portion of the
booms. The angle at which the booms at the nozzle mouth engages the
water must not be too large, or turbulence which would drive the oil
downward might result. During the higher tow speed tests, the strong
horizontal vortices generated at the leading portions of the booms were
felt further downstream and instigated oil loss. Boom stability failure
at low current velocities (0.75 m/s) could also result from too great an
attack angle.
Observation and photo/video documentation of tests using oil are
vivid and to the point. The use of hot film anemometry at OHMSETT has
proven very delicate and time-consuming in boom study. Problems inherent
with large-scale testing also produce problems in probe placement and
protection. However, small-scale testing using hot film probes and
streamers could be helpful. Systematic variation of boom skirt depth
and position might delineate areas where oil could be contained behind
the boom, as well as in front.
-------
SECTION 3
TEST APPARATUS DESCRIPTION
BOOM AND RIGGING DESCRIPTION
The B.F. Goodrich 18 PFX Seaboom was used for these tests. Design
characteristics are listed below. Four boom sections were painted and
marked in metres to allow unambiguous topside and underwater reference
for photographic, video, and observer documentation. The booms were
rigged in the desired configuration with the leading ends attached to
tow points on the main bridge (Figure 1).
Figure 1. Nozzle con-
figuration showing main
bridge tow points and oil
distribution points.
-------
The trailing ends of the boom were either attached to tow points on the
auxiliary bridge (Figure 2), tied to a tow-back device (Figure 3),
or held by ropes to the bridges. The tow-back device was clamped to the
bridge drive cable and rode along the tank wall when the bridge moved.
Figure 2. Exit of 20° "V" configuration showing auxiliary
bridge tow points.
i
\ ~
Figure 3. Tow back device attached to trailing end of diversionary boom.
5
-------
This moveable tow point permitted the boom to be tensioned during tests
and returned to the tank's north end starting point after each test run.
Parachute lines, 1.27 cm in diameter, were attached to the boom floatation
both at the boom section junctions and at intermediate points to maintain
the nozzle configurations. A spreader bar was used where a venturi
effect tended to collapse the two sides of the configuration into each
other. Each spreader bar consisted of a piece of lightweight aluminum
tubing with a tie line slipped through and tied off at each end to the
boom floatation. The oil slick was distributed uniformly onto the water
surface ahead of the boom over the entire projected sweep width. Tests
performed with the parabolic and quarter-circle exit configurations had
the skirt of the boom tied up out of the water to reduce turbulence
(i.e.— only the floatation had an effect upon the oil in the exit
portion).
Design Characteristics
1. Draft—0.30 m
2. Freeboard—0.15 m
3. Floatation—continuous chambers of closed cell foam, protected
by 0.635 cm coating of polyvinyl chloride and secured at the
ends with wooden plugs
4. Ballast—tubular extrusion, filled with lead shot and sand
5. Skirt material—0.635 cm thick vinyl sheet reinforced with rib
handles of urethane
6. Tension member—self tensioning boom
7. Weight—11.01 kg/m
8. Excess buoyancy—10.42 kg/m
9. Standard section length—7.16 m
VIDEO AND PHOTOGRAPHIC DOCUMENTATION
Cameras provided visual documentation of test layout, equipment,
and performance characteristics. A black and white TV camera in a
waterproof case provided underwater video coverage, which was recorded
on 2.54-cm video tape. Topside and tank-side window, coverage was
provided by two 16-mm movie cameras and a 35 mm still camera. A 1.8 x
1.8-m mirror and frame was positioned on the tank bottom at a 45° angle
to provide a vertical underwater view of the boom when shooting through
the window.
TEST FLUID DESCRIPTION
Circo (Sun Oil Company brand name, Philadelphia, Pennsylvania) medium
-------
oil was used in all tests. The specifications of the oil were as follows:
Specific Gravity 0.921
Viscosity 190 x 10~6 m2/s @ 22.7°C
Interfacial Tension* 19.2 x 10~3 N/m @ 22.1°C
Surface Tension* 35.3 x 10~3 N/m @ 22.7°C
% Water and Sediment 0
*Tested with OHMSETT tank water (16 ppt salinity)
This oil approximated the characteristics of one of those recommended
in American Society for Testing and Materials (ASTM) Committee F-20's
proposed standard for testing advancing oil skimmers.
-------
SECTION 4
TEST PLAN AND PROCEDURE
TEST RATIONALE
The use of dyed oil was found to be the best method for determining
boom performance. Earlier studies of boom hydrodynamics (2, 3) performed
at the USEPA OHMSETT facility incorporated hot film anemometry, dyed
water streams, and dyed oil to observe and record flow phenomena around
a boom. However, the tow speeds were all equal to or less than 1.07 m/s
and only one boom configuration (one-sided diversionary) was investigated.
The current series of tests initially used hot-film probe analysis of
the turbulence around the oil boom and streamers attached to the boom or
towed in front of it from a vertical staff to observe flow patterns.
The boom was rigged in the straight, single diversionary mode, and the
hot-film probe was positioned as closely behind the skirt as possible.
Since the boom and tow lines stretched under tow, such placement could
have been hazardous to the probe. Because of the time required for
placement, calibration, and troubleshooting, use of the probe was terminated.
The streamers (colored yarn) were observable in various locations along
the boom and at different lengths, depths and tow speeds. However, oil
loss mechanisms and quantities could not be adequately determined. The
use of streamers was later discontinued in favor of dyed oil.
The series of dyed oil experiments began with the boom rigged in
the single boom diversionary mode (Figure 4). Oil was distributed
evenly over the sweep width of the boom as it was towed southward.
Underwater video and photography recorded the failure points along the
boom. The boom tow speed was kept constant during a single pass down
the tank. After each run the oil was skimmed back to the north end of
the tank, and the next test was run at a higher tow speed. Following
the test run where oil loss was excessive because of high tow speed, the
boom configuration was changed and the tests of that new configuration
were begun. The boom configurations, in order of testing, included 32°
diversionary (Figure 5), 20° diversionary (Figure 6), 20° "V" (Figure 7)
and parabolic nozzle (Figure 8). "Belled" exit nozzle (Figure 9) and
constricted throat with "belled" exit nozzle (Figure 10) configurations
were tested at the end of the test series (ending April 15, 1977) to try
to reduce the eddy current and entrainment of oil left by the passing
boom. The last test series (ending September 30, 1977) involved adding
another boom section to each side of the nozzle configuration and rig-
ging them to form a straight exit (Figure 11), a parabolic exit (Figure
12) and a quarter-circle exit (Figure 13).
-------
OIL/WATER
FILTER
AREA
1
n
_0
CL
WAVE FLAPS
OIL DISTRIBUTION POINTS
jQ.Q.Q.Q.Q-O. Q . Q , O
1
DIRECTION OF TOW \
v.
CONTROL BUILDING
1. Test Director
2. Oil Distributor
3. Photographer
4. Test Engineer
5. Photographer
6. Bridge Operator
7. Chemist
3
The Bridges and Video
Truss, which travel
as one unit with the
booms, are shaded on
this and subsequent
drawings.
LAB/OFFICE
BUILDING
Figure 4. General test set-up and personnel placement during testing.
-------
Oil Distribution Points
ooooooooo
1
Main Bridge
/ / / J_J
Parachute Moorin
Lines
Video Truss
Four sections of
boom, each 7 m
long
Direction of
tow
Auxiliary Bridge
Tow Back Devic?
Figure 5. Test set-up for 32° single diversionary boom.
10
-------
18.3 m
'//// //////.///////////Main Bridge////.
Parachute
Mooring Lines
Three sections
of boom, each 7 iri
long
Video Truss
Direction of Tow
Auxiliary Bridge
Figure 6 . Test set-up for 20° single diversionary boom.
11
-------
V/////////"
Two sections of boom,
each 7 m long on each
Tie Lines
Direction of Tow
Auxiliary Bridge
t—^. , * r , , e
£;U 4.-1 mi J
Figure 7. Test set-up for 20° double diversionary or "V" boom configuration.
12
-------
Bridge // / / // /////
Line Boom
Lengths Position
9.02 m 1.75 m
Connecting
Lines
Two sections of boom
each 7 m long on eac
side of the nozzle
/^> Video Truss
Direction of Tow
Auxiliary Bridge /s1-2 ™ /
Figure 8. Test set-up for the parabolic nozzle boom configuration.
pare with Figure 1).
(Com-
13
-------
'/ / // / Main Bridge
Connecting
Lines
Two sections of
boom, each 7 m long
on each side of the
nozzle
2.12 m 10.5
Video Truss
Tie Lines
Direction of Tow
/ Auxili
/ / / '/
.1 m 5\
Figure 9. Test set-up for "belled" exit nozzle boom configuration.
14
-------
9.02 m 1.75
7.0 m 3.5 m
5.3 m 5.25
4.0 m 7.0 m
Two sections of boom
each 7 m long on each
side of the nozzle
0.61 m 10.5 m
Video Truss
Direction of Tow
Tie Lines \
Auxiliary Bridge
/ / / / / /
Figure 10. Test set-up for constricted throat and "belled" exit
nozzle configuration.
15
-------
Typical nozzle
configuration with two
additional straight
boom lengths added to
form an exit.
Dimensions of nozzle
are given in Figure 8.
The exit sections are
parallel.
Two sections of
boom, each
7 m on each
side of the
nozzle
Direction of
Tow
Spreader Bars
(3)
Video Truss
Area where the two
additional boom
sections left
the water
Tie Lines
/
Figure 11. Test set-up for the parabolic nozzle configuration with the
straight, lifted exit.
16
-------
Connecting
Lines
Two sections
of boom, each
7 m long on each
side of the nozzle
Spreader
Bars
Added boom sections
forming parabolic
exit
Typical nozzle
configuration with two
additional boom lengths
added to form an exit.
Dimensions of the nozzle
are the same as given
in Figure 8. The exit
sections are a mirror
image of the last two
sections of the nozzle.
Direction of Tow
Video Truss
Securing Lines
Figure 12. Test set-up for parabolic nozzle configuration with para-
bolic exit.
17
-------
Main Bridge
Video
Truss
Two sections
of boom,
each 7 m
long on
each side of
the nozzle
Typical nozzle
configuration
with two
additional boom
sections for
the exit.
Dimensions of
the nozzle are
given in Figure
8. The exit
sections have
a radius of
4.46 m.
Added section of
boom to form
quarter-circle _j _
exit
Direction of
Tow
Auxiliary Bridge
Figure 13. Test set-up for parabolic nozzle configuration with quarter-
circle exit.
18
-------
A basic parabolic contour was chosen for the nozzle configuration
(Figure 14). This gave an easily reproducible form with which the
investigation of special boom configurations could begin. Cross section
shapes of gas nozzles could only be used as a guide due to the difference
in compressibilities between air and water. The specific distances
between the booms were calculated from the equation shown with the
drawing. This equation was derived on the basis that the sweep width
and discharge opening being identical with the 20° double diversionary
"V" configuration.
PROCEDURES
The boom was rigged in the desired configuration and the main
bridge was set in motion southward at the correct tow speed. Oil was
pumped from the storage tanks on the main bridge to the distribution
points ahead of the main bridge and discharged onto the water surface.
The oil slick was maintained between 1 to 2 mm thick. Observers on the
moving bridge and at the underwater windows recorded the points of
failure and the approximate amount of oil loss during the run. Video
records and photographs were also taken during the test runs. After
each test run was completed, the oil was skimmed to the north end of the
tank and the next test run was begun. Excessive oil loss and boom
stability failure determined the upper limit of tow speed.
19
-------
NJ
o
0 _< x <_ 13.39
dy/dx = ± x
18.38
3
6
10
11
13
0
.35
.70
.04
.74
.39
± 0.
± 1.
± 1.
± 3.
± 4.
± 5.
76
06
98
50
51
64
±
±
±
±
+
0.
0.
0.
0.
0.
0
18
36
55
64
73
10
20
28
32
36
0
.0
.0
.6
.5
.0
Dist. along boom
from main bridge
Figure 14. Design of parabolic nozzle configuration.
-------
SECTION 5
DISCUSSION OF RESULTS
The percent oil losses under and away from the boom were estimated
by observers during the test and re-checked afterwards by using photo-
graphic and video records. The results are shown in Figures 15 through
18 and Tables 1 through 3. The lost oil was not recovered and measured.
While the loss accounting may be inexact by 10 or 15 percent at most,
the relative quantities of oil lost from one test to another are con-
sidered reliable.
Figures 15 and 16 are plots of tow speed vs. percent oil loss for
32° and 20° diversionary booms, respectively, and show the relative
containment limits of the two boom configurations. The better performance
of the 20° over the 32° configuration is quite apparent. Analysis of
these results indicates that an additional investment in boom and securing
lines to compensate for the reduced sweep width inherent in the lesser
angles may be cost effective (see Appendix B), since it permits con-
trolling oil that would otherwise be lost because of the current.
Figures 17 and 18 are plots of tow speed vs. percent oil loss for
20° "V" and nozzle configuration, respectively, and show the relatively
greater effectiveness of the nozzle configuration at higher tow speeds.
Its poorer results at the lower tow speeds are probably due to the
increased angle of the leading edge of the booms.
Oil droplets passing beneath the skirt of a boom are not necessarily
lost. They may be caught in the upwelling eddy and held against the
back side of the boom. Oil held in this relatively quiet zone can be
successfully diverted along the rear of the boom. The contribution of
such diversion, shown in Figures 15 through 18, can be substantial.
However at high tow speeds (>1 m/s), the oil droplets are smaller and
entrain deeper into the water column. When this happens, there is less
chance for the droplets to rise in time to reach the quiet zone.
The question whether a quantum increase in oil loss from in front
of a diversionary boom occurs when the perpendicular component of current
exceeds 0.51 m/s (a critical speed for oil shedding beneath a boom
rigged perpendicular to the current (4)) can be investigated using the
data obtained in these tests. As a boom is angled nearly parallel to
the current, the normal (to the boom) component of the current speed
decreases. The normal component of current to the boom is directly
proportional to the sine of the rigging angle and that component reaches
21
-------
NJ
Retained in
front of the boom
Total retained
Observed
— Extrapolated
Retained
behind the boom
H
O
H
cn
H
O
Figure 15.
ITC)
TOW SPEED (m/s)
(Normal component of tow speed)
Performance of B.F. Goodrich 18 PFX boom (32° angle diversionary mode
28.5 m long).
-------
U)
100
90
80
70
g 60
50
M
O
40
30
20
10 h
Current
Boom
— Observed
~ Extrapolated
Retained in
front of the boom
Retained
behind the b
0.5 1.0 1.5
TOW SPEED (m/s)
(Normal component of tow speed)
- 10
20
- 30
- 40
- 50
- 60
- 70
- 80
90
o
H
H
W
s
100
2.0
Figure 16.
Performance of B.F. Goodrich 18 PFX boom (20° angle-diversionary mode
21.6 m long).
-------
K>
JS
100
90 _
80
70
g 60
H
B 50
M
O
6-S
40
30
20
10
Current
I
Boom
Retained in
front of the boom
Tank
Wall
Retained behind
the boom
10
20
30
40
o
H
50 £
o
60S
70
100
TOW SPEED (m/s)
Figure 17. Performance of B.F. Goodrich 18 PFX boom (20° "V" configuration,
14.3 m on each side).
-------
to
I/I
100
90
80
70
60
p
w
I50
40
30
20
Current
Boom
Retained in
front of the boom
•Tank Wall
Retained behind
the boom
Total
Retained
- 20
30
40
10
H
O
H
-T 50 H
o
60
o
70
80
90
100
1.25
1.50
1.75
2.0
TOW SPEED (m/s)
Figure 18. Performance of B.F. Goodrich 18 PFX boom (parabolic nozzle configuration,
14.3 m on each side).
-------
TABLE 1. SINGLE DIVERSIONARY BOOM TEST RESULTS
KJ
Test
no.
A-l
A- 2
Boom Tow Failure
ang. speed points
(deg.*) (m/s)
32 0.70 Cusps
32 0.81 Cusps and
some along
boom
Oil
Oil away Type
be- from of Slick
neath rear loss thick Comments
(%) (%) ** (mm)***
1 0 Sh 1.94 No vortices formed
along boom
5 0 Sh 1.99 No vortices formed
along boom
A-3
A-4
A-5
A-6
A-7
32
32
32
20
20
0.91
1.01
1.26
0.56
0.81
Cusps and 10
intermittently
along boom
Cusps predom- 50
inantly; along
boom increasing
toward the end.
All along boom 70
starting at
3.5 m
None
None 0
* 32 - four boom sections
20 - three boom sections
**Sh - Shedding
***Based upon a 9.1 m width
5 Sh 1.72 Vortices after boom
passes. None along
skirt.
50 Sh 1.68 Vortices after boom
passes. None along
skirt.
50 Sh 1.48 Vortices after boom
passes. None along
skirt. Entrainment
severe.
0 None 1.60 No entrainment after
boom passes
0 None 1.14 No entrainment after
boom passes
(Continued)
-------
TABLE 1 (Continued)
ro
Test
no.
A-8
A- 9
A-10
A-ll
A-12
Oil
Oil away
Boom Tow Failure be- from
ang. speed points neath rear
(deg.*) (m/s) (%) (%)
20 1.01 Cusps 7 0
20 1.26 Cusps, amount 10 0
increasing
down the boom
20 1.52 Starts at 5 m 30 5
(first cusps
at 7 m) sheds
at all cusps
20 1.67 All along 50 10
boom
No lines 1.01 Begins at 16 m 80 50
from front.
Very severe
Type
of Slick
loss thick Comments
** (mm)***
Sh 1.00 Small standing waves set
up by parachute lines.
Small entrainment and
vortices after boom
passes.
Sh 1.10 Standing wave set up by
line. Vortices and
entrainment after boom
Sh 1.10 Standing wave with some
entrainment because of
lines. Entrainment and
vortices after boom.
Sh 1.10 Standing wave, severe
entrainment . Planing
failure in first section.
Sh 1.40 Severe entrainment and
vortices following the
boom. The boom was
unstable at 1.26 m/s.
+Shedding (no vortices)
-------
TABLE 2. DOUBLE DIVERSIONARY BOOM ("V") TESTS RESULTS
to
00
Test
no.
B-l
B-2
B-3
B-4
B-5
B-6
Boom
ang.
(deg.*)
20
20
20
20
20
20
Tow
speed
(m/s)
0.56
0.81
1.01
1.26
1.52
1.67
Failure
points
None
None
None
At cusps
All along
boom
All along
boom
Oil
Oil away Type
be- from of Slick
neath rear loss thick
(%) (%) ** (mm)***
0 0 None 1.12
0 0 None 1.15
0 0 None 1.15
5 0 Sh 1.07
10 5 Sh 1.00
30 15 Sh 1.07
Comments
No entrainment. No
vortices.
Small vortices after
boom.
Small vortices after
boom.
Slight entrainment and
vortices follow boom.
Entrainment begins at
6 m and continues along
boom. Severe entrain-
ment follows.
Entrainment begins at
6 m and continues along
boom. Severe entrain-
ment follows.
*20 - two boom sections
**Sh - Shedding
***Based upon a 9.1 m width
-------
TABLE 3. DOUBLE DIVERSIONARY (NOZZLE) BOOM TEST RESULTS
N>
vO
Test
no.
C-l
C-2
C-3
C-4
C-5
C-6
Boom
ang.
(deg.*)
Nozzle
(2 sec.
each side)
Nozzle
Nozzle
Nozzle
Nozzle
Nozzle
Tow
speed
(m/s)
0.56
0.81
1.01
1.26
1.52
1.67
Oil
Failure be-
points neath
(%)
None 0
None 0
Small losses 3
at 2 m
Small losses 10
at 4 m
Losses start 15
3 m and con-
tinues to 7 m
Losses all 20
along boom
Oil
away
from
rear
(%)
0
0
0
3
5
7
Type
of
loss
**
None
None
Sh
Sh
Sh
Sh
Slick
thick
(mm)***
1.09
1.08
1.08
1.10
1.09
1.09
Comments
Spreader bar at rear
causes standing waves
Turbulence on leading
edge of nearest boom
Loss on nearest boom
Standing wave set up
up by ropes
Front end turbulence
causes failure
Difficult to see if
failure is consistent
along the boom
(Continued)
-------
TABLE 3 (Continued)
Oil
Test
no.
C-7
C-8
Boom
ang.
(deg.*)
Nozzle
with
belled
exit
Con-
stricted
nozzle
exit
belled
Tow
speed
(m/s)
1.01
1.01
Oil away
Failure be- from
points neath rear
Start at 4 m 10 3
losses along
boom
Losses begin 10 3
at 3.5 m and
continue
down boom
Type
of Slick
loss thick
** (mm)***
Sh 1.08
Sh 1.08
Comments
Losses do not appear to
be increasing along boom
Losses do not increase
along the boom. Con-
stricted throat in-
creased boom angle
slightly.
*Sh - Shedding
**Based on 9.1 m width
-------
0.51 m/s against 32° and 20° booms at about 1 and 1.5 m/s, respectively.
Figures 15 and 16 show oil loss as a function of the perpendicular
(normal) component of tow speed and generally confirm the 0.51 m/s
failure speed.
The nozzle configuration required the use of spreader bars to
prevent the booms from collapsing into the center due to the venturi
effect. The bars were placed at the nozzle exit and in the narrow
section of the boom exit configurations. This would be another con-
sideration when employing the nozzle configuration in the field. If the
booms are allowed to collapse into each other, the oil could shed beneath
them because of flow restriction.
Additional testing should be done to determine the effect of boom
length on oil loss. Comparing the 20° diversionary and the 20° "V"
configuration results, one can see that the extra boom length affected
oil loss under the boom, but not away from the rear of the boom. The
boom angle, not the boom length was the more critical parameter in these
tests. At a tow speed of 1.02 m/s, the losses from the 32° diversionary
were over five times those of the 20° diversionary boom.
31
-------
REFERENCES
1. Beyer, A.H., and L.J. Painter. Estimating the Potential for Future
Oil Spills from Tankers, Offshore Development and Onshore Pipelines.
In: Proceedings of the 1977 Oil Spill Conference, American Petroleum
Institute, Washington, D.C., 1977. pp. 21-30.
2. McCracken, W.E. Hydrodynamics of Diversionary Booms. EPA-600/2-78-075
U.S. Environmental Protection Agency, Cincinnati, Ohio, 1978. 46 pp.
3. McCracken, W.E., and F.J. Freestone. Hydrodynamics of Diversionary
Booms. In: Proceedings of the 1977 Oil Spill Conference, New Orleans,
Louisiana, 1977. pp. 329-334.
4. Lindenmuth, W.T., E.R. Miller, Jr., and C.C. Hso. Studies of Oil
Retention Boom Hydrodynamics. Hydronautics, Inc., Laurel, Maryland,
1970. 81 pp.
32
-------
APPENDIX A
OHMSETT
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
The U.S. Environmental Protection Agency is operating an 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 of oil and hazardous material spills.
The primary feature of the facility is a pile-supported, concrete
tank, 203 metres long, 20 metres wide and 2.4 metres deep. The tank can
be filled with fresh or salt water. The tank is spanned by a bridge
capable of exerting a force up to 151 kilonewtons, which permits the
towing of floating equipment at speeds up to 3 metres/second for at
least 45 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 metres ahead of the device being tested, so that
reproducible thicknesses and widths of the test fluids can be achieved
with minimum interference by wind.
The principle systems of the tank include a wave generator and
absorber beach, and a filter system. The wave generator and absorber
beach have capabilities of producing regular waves up to 0.7 metre high
and 28.0 metres long, as well as a series of reflecting, complex waves
meant to simulate the water surface of a harbor or sea. The tank water
is clarified by recirculation through a 0.13 cubic metre/second dia-
tomaceous earth filter system in order to permit full use of a sophis-
ticated 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 skimming board which can move oil onto the
north end of the tank for cleanup and recycling.
>
When the tank must be emptied for maintenance purposes, the entire
water volume of 9842 cubic metres 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. One such device is a trailer-
mounted carbon treatment unit for removing organic materials from the
water.
Testing at the facility is served from a 650 square metres building
33
-------
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 con-
tractor, Mason & Hanger-Silas Mason Co., Inc., provides a permanent
staff of fourteen multi-disciplinary personnel. The U.S. Environmental
Protection Agency provides expertise in the area of spill control tech-
nology, and overall project direction. An aerial view is given in
Figure A-l.
For additional information, contact: OHMSETT Project Officer, U.S.
Environmental Protection Agency, Research & Development, Edison, New
Jersey 08817, 201-321-6631.
Figure A-l. Aerial view of OHMSETT.
-------
APPENDIX B
This brief table illustrates the boom length necessary to cover
various sweep widths using 20° and 32°-angle diversionary configurations.
These figures do not include an opening at the apex.
TABLE B-l. DIVERSIONARY BOOM LENGTH vs. ANGLE COMPARISON
Sweep width (m) 20°-angle boom length
25
50
75
100
200
73.1
146.2
219.3
292.4
584.8
47.2
94.4
141.6
188.8
377.6
Though the 20°-angle boom configuration requires 1.55 (inverse
ratio of the sines) times as much boom as the 32°-angle configuration,
the oil diversion performance is many times better. At 1.25 m/s, the
32°-angled boom loses half the oil it encounters, while the 20°-angled
boom loses none.
35
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-186
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
BOOM CONFIGURATION TESTS FOR CALM-WATER, MEDIUM-
CURRENT OIL SPILL DIVERSION
>. REPORT DATE
August 1978 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Michael K. Breslin
8. PERFORMING ORGANIZATION REPORT NO*
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Mason & Hanger-Silas Mason Co., Inc.
P. 0. Box 117
Leonardo, New Jersey 07737
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-03-0490
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory-Gin., OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT " '
The purpose of this test program was to determine the effects of boom angle,
length, and rigging configuration on diversion of oil floating on moving streams.
The B.F. Goodrich Seaboom was chosen for the program because of its availability
durability, and stability. It was rigged in different diversionary modes and towed
into an oil slick at the U.S. Environmental Protection Agency's Oil & Hazardous
Materials Simulated Environmental Test Tank (OHMSETT) facility at various speeds,
until critical stability speed was attained. Boom preformance was recorded on photo-
graphs, video tapes, and observer notes. Results were evaluated in terms of the
percentage of oil lost beneath the boom and away from the rear of the boom. A
"nozzle-shaped" boom configuration achieved the best diversion at tow speeds examined
above 1.0 m/s. Different exits from the nozzle configuration were investigated to
find which one released the oil with the least amount of entrainment and spreading.
A straight exit with tapered ends worked best. Tests were conducted in accordance
with a test matrix developed by the U.S. Environmental Protection Agency.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Performance tests
Booms (equipment)
Diverting
Water Pollution
Oils
Spilled oil cleanup
Diverting floating oil
13B
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
46
20. SECURITY
UNCLASSIFIED
22. PRICE
•PA f
2219.1
36
1971 - 7SM40/14S4 ftoflMi Ml
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