600281154
PERFORMANCE TESTING OF THE SOVIET OIL/DEBRIS SKIMMER
by
H.W. Lichte
Mason & Hanger-Silas Mason Co., Inc.
Leonardo, New Jersey 07737
Contract No. 68-03-26^2
Project Officer
John S. Farlow
Oil and Hazardous Materials Spills Branch
Municipal Environmental Research Laboratory
Edison, New Jersey 08837
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO W268
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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 trade names or
commercial products constitute endorsement or recommendation for use.
ii
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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 complexity 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 the performance testing of the Soviet Oil/Debris Skimmer
under a variety of controlled conditions. Based on these results, a number of operating
techniques are of interest to those interested in specifying, using, or testing such
equipment. Further information may be obtained through the Oil and Hazardous
Materials Spills Branch in Edison, New Jersey.
Francis T. Mayo
Director
Municipal Environmental Research Laboratory
Cincinnati
HI
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ABSTRACT
Performance evaluation of a Soviet oil skimmer was conducted at the United
States Environmental Protection Agency's Oil and Hazardous Materials Simulated
Environmental Test Tank in 1979. The program was sponsored through the 3oint
U.S.-U.S.S.R. Project on Prevention and Cleanup of Pollution of the Marine Environ-
ment from Shipping. The skimmer was provided by the Black Sea Central Planning and
Designing Bureau, Odessa. The test program was designed at OHM SETT to evaluate
the oil skimming capability of a specially modified Soviet skimmer, Model 2550/4. The
self-propelled vessel is 17.7 meters long and weighs 39 metric tons. The 111 kilowatt
diesel engine drives a ducted propeller water jet propulsion system. The vessel is
capable of five knots forward speed and skims effectively at speeds from zero to two
knots.
The unique combination of various weir designs into one system, vessel
mobility, the efficient use of energy, a series type oil/water gravity separator, and the
propulsion techniques all suggest it to be an effective harbor skimmer. The oil
recovery rate of 12.4 cubic meters per hour was confirmed using OHMSETT heavy test
oil (1.5 pascal seconds and 0.95 specific gravity) in calm water conditions. Recovery
efficiency was 85 percent at 1.5 knots forward speed and throughput efficiency was 90
percent at one knot forward speed. Performance dropped for skimming light oils at
faster speeds and higher wave conditions. The skimmer collected 64 percent of the
81.3 cubic meters oil volume encountered during the test program.
This report was submitted by Mason & Hanger-Silas Mason Co., in fulfillment of
Contract Number 68-03-2642, lob Order No. 55, with the U.S. Environmental
Protection Agency. The test program was completed in July 1979.
IV
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables vi
List of Conversions vii
Abbreviations and Symbols viii
Acknowledgments ix
1. Introduction 1
2. Conclusions and Recommendations 2
3. Device Description ." 3
The Vessel 3
The Skimming Operation 3
4. Test Plan and Procedures 11
Test Plan 11
Test Procedures 12
5. Test Results 15
6. Discussion of Results 26
Fluid Flow 26
Skimming Oil 26
Appendices
A. OHMSETT Test Facility 28
B. Test Fluids 30
C. OHMSETT Waves 31
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FIGURES
Number
Pajje
1 Soviet Oil/Debris Skimmer at OHMSETT with the bow doors
wide open . 4
2 Cutaway sketch of the integrated Soviet Oil/Debris Skimmer
system 6
3a Debris handling system, view from bow operator's work station ... 7
3b Debris handling system, close up 7
3c Debris handling system, close up of chain conveyor, empty settling
basin, and coke filter entrance 8
»
<4 Representative 1 ow diagram of the oil collecting process 9
5 Flo.w area of the Soviet Oil/Debris Skimmer relating the duct
and weir sizes 10
TABLES
Number
1 Soviet Skimmer Fluid Flow Tests (no oil) 17
2 Soviet Skimmer Performance (Circo X Heavy Oil) 18
3 Soviet Skimmer Performance (Circo 4X Light Oil) 20
^ Soviet Skimmer Adjustments (Circo X Heavy Oil) 22
5 Soviet Skimmer Adjustments (Circo 4X Light Oil) 2k
VI
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LIST OF CONVERSIONS
ENGLISH TO METRIC
centistoke meter /second 1.000 E-06
degree Fahrenheit Celsius t = (tc-32)/1.8
erg joule 1^300 £-07
foot? meter. 3.0*8 E-01
foot meter 9.290 E-02
footfminute meter^second 5.080 E-03
foot /minute meter /second 4.719 E-04
foot-pound-force joule - 1.356 E+00
gallon (U.S. liquid) meter ^ 3.785 E-03
gallon (U.S. liquid)/minute meter /second 6.309 E-05
horsepower (550 ft Ibf/s) watt 7.457 E+02
inch., meter- 2.540 E-02
inch meter 6.452 E-04
knot (international) meter ^second 5.144 E-01
liter meter 1.000 E-03
pound force (Ibf avoir) newton 4.448 E+00
pound-mass (Ibm avoir) kilogram 4.535 E-01
vii
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ABBREVIATIONS AND SYMBOLS
Abbreviations
CWL
m
hp
kW
km
m3
rn /hr
rpm
kPa
psi
mm
cm
dm
Q
t
v
RE
TE
ORR
VMD
AVD
v
VVD
w
-constructive water line
-rneter
-horsepower
-kilowatt
-kilometer
-cubic rneter
-cubic meter per hour
-revolutions per minute
-kilopascals
-pounds per square inch
-millimeter
-centimeter
-decimeter
-oil distribution rate
-slick thickness in skimmer basin
-tow speed
-recovery efficiency
-throughput efficiency
-oil recovery rate
-main duct velocity
-Pitot tube constant
-gravity constant
-main duct flow
-vertical duct flow
-area of duct
-area of vertical ducts
-direct reading of vertical duct velocity
-skimmer basin width
Symbols
--percent
viii
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ACKNOWLEDGMENT
This skimmer test program required innovative solutions to several engineering
problems. First was the transportation of the huge skimmer from the U.S.S.R.
container ship and its return a month later. Mr. R.A. Ackerman managed this effort,
calling on new resources, and in the midst of the New York Harbor tug boat strike.
His effective solution incorporated one of the largest U.S. over-the-road mobile
cranes, and also tandern lifts of the skimmer, by the U.S. Navy. He also managed to
prevent during the test program the subtle concern for interference from the large
number of visitors.
The second engineering problem to be solved was communications and transfer
of technology. In this regard, the Soviet engineers and technicians were outstanding.
Mr. Sergei Nunaparov was responsible for the background work leading to this test
program and the excellent Operations Manual. Two Soviet technicians were on site for
the month-long test program at OHMSETT. Messrs. Victor Polishchuk and Vladimir
Semenov were excellent engineers, communicators, and charming guests. Rarely did
the language barrier interfere, but when it did, the mutual understanding of Bernoulli's
principles in fluid mechanics was the translator.
The OHMSETT staff contributions made the daily work schedule cost effective
and timely. The cooperation of various federal agencies and the U.S. Navy facility,
Naval Weapons Station Earle allowed smooth operations.
IX
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SECTION 1
INTRODUCTION
Oil and hazardous waste spills on the world's waterways are problems which
know no territorial boundary. Under a bi-national agreement, the United States and
the Soviet Union tested the latest Russian design for picking up floating oil spills at
the Environmental Protection Agency's Oil and Hazardous Materials Simulated
Environmental Test Tank (OHMSETT) in Leonardo, New Jersey during June 1979.
The Soviet Oil/Debris skimmer, Model 2550/3 and the newer 2550/4 are seen
frequently in the port water areas of the U.S.S.R. At least 120 of the 2550/3 craft
have been constructed, and on the order of 50 of the 2550/4 are thought to have been
built since 1974. The Model 3 craft is 14.83 m long, has a beam of 4.3 m and a mean
draft of just over 1.6 m. The Model 4, 17.4 m long has a more conventional bow which
gives it better speed (5 kt vs. 3.8 kt) than the Model 3 and better range and sea-
keeping qualities. These craft are designed to collect approximately 12 tons of oil per
hour in calm water and to collect one cubic meter of debris per hour.
Oil and debris are initially dumped into a 12 m^ capacity receiving-settling
tank. The oil-water mixture is then pumped into two 11 m^ capacity gravity
separation and storage tanks. Both models can be rigged with containment booms
which are extended by tenders during skimming operations. The Model 4 has two
hydraulically-actuated doors in the bow which can be opened to give a maximum sweep
path of 8 m. In addition to their use as skimmers these craft transport waste waters
from ships to treatment or receiving facilities on shore.
The 17.4 m, 43 ton skimmer, shipped from Odessa, U.S.S.R, was tested under the
supervision of the Cincinnati Municipal Environmental Research Laboratory's Oil and
Hazardous Materials Branch in Edison, New Jersey. The arrangements for the testing
were made through the U.S./U.S.S.R. Task Group on Prevention and Cleanup of
Pollution of the Marine Environment from Shipping.
The skimmer was lifted into OHMSETT's 20-m wide, 203-m long wave/tow tank
to evaluate the effect of such variables as oil type and thickness, wave height and
type, and the speed of advance through the water.
OHMSETT provided a controlled, environmentally safe facility for testing the
skimmer's effectiveness and rate of oil collection under a variety of different
conditions.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
The performance of the Soviet Oil/Debris Skimmer, Model 2550A, fulfilled
design requirements well. The combination of the unique application of various weirs
into one system, mobility, the efficient use of energy, the incorporation of series
oil/water separation, the propulsion system, and use of high oil/water flow conditions
suggest that the skimmer is the best of its class in harbor operations. The actual oil
collection performance was near the design specifications and proved better in the
heavy oil than in the light, as expected because of entrainment. The high throughput
efficiencies in the normal advancing and stationary modes were commendable.
The centrifugal pump used in the gravity separation system was effective in
transferring oily water. The second onboard pump, a vortex fire/ballast system had a
significantly smaller capacity. Future modifications of the design should address the
incorporation of a positive displacement pump somewhere in the circuit. The two-man
operation of the vessel was difficult. One was needed on the bow while the second
divided his time between the wheel house and pump controls. Skimming oil when under
way should include an additional man.
Future testing of the skimmer should address, in more detail, the efficiency of
the coke filter system, use of the gill door in the skimming mode, and larger oil
volume performance tests requiring significant quantities of oil in the port-side
storage.
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SECTION 3
DEVICE DESCRIPTION
THE VESSEL
The Soviet Oil/Debris Skimmer (Model 2550/4) tested at OHMSETT (see
Appendix A) is a fourth generation design for recovery of floating pollutants, oil, and
debris from the water surface. The vessel can navigate offshore and in the roads
within limits established by the USSR Register of Shipping. The maximum range is
18.53 km off port with a sea force of 3 and wind force not exceeding 4 in Soviet
standards (Reference 1).
The vessel is 17.7 m long, with a constructive water line (CWL) beam of 4.3 m,
and a total weight of 39 metric tons. The CWL draft is 1.6 m, and the freeboard is 2.4
m. Hydraulically controlled bow doors provide an adjustable oil slick sweep width up
to 8 m. Figure 1 displays the vessel at OHMSETT with the bow doors wide open.
The self-propelled, one-deck vessel is normally operated by two persons: A
navigator-engineer and an able-bodied motorman. The crew does not live aboard, but
there are provisions for fresh water, wash water, toilet, deck house, change room, heat
and navigational aids. The main engine is a diesel rated at 135 HP (100 kW) at 1900
rpm. There is a reversible reductor transmission to drive the 0.54-m diameter ducted-
propeller water jet propulsion. Other power takeoffs are used for electricity, air,
hydraulic, and pump belt drive systems. The vessel is capable of 5 knots forward
speed. Speed during oil collection varies between standing still in a dock area to
advancing at 0.5 to 2 knots.
Onboard storage provides 1.83 m^ of ballast, 31 m^ dry compartments, 19.3 m-*
recovered fluids (oil, water), 1.3 m3 diesel fuel, and 0.23 m^ hydraulic oil. The deck
house is large enough for a sleeper, if required. The engine-roorn layout is spacious to
work in, and the pump room has enough head room for convenient repair work.
THE SKIMMING OPERATION
The skimmer can be operated in both an advancing mode and a stationary mode.
The speed and direction of the vessel is controlled by reaction rudders downstream of
the propeller duct. The unique stationary mode requires the vessel to manuever its
1. Operational Manual, Oil/Debris Skimmer (ODS) 2550/4-901-008, USSR Black
Sea Central Planning and Designing Bureau, 1979, 63 pp.
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Figure 1. Soviet Oil/Debris skimmer at OHMSETT with the bow doors open.
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stern to a dock or piling and close the reaction rudder. The current then caused by the
prop wash pushes floating oil around either or both sides of the bow door opening and
subsequently is sucked into and over the broad crested weir.
The skimmer operators have various controls and equipment settings to effect
the best oil skimming modes. Vessel trim is set using a combination of ballast, bow
door opening, and vessel speed. Figure 2 is a cutaway sketch of the integrated system.
The debris handling basket and mechanism was not tested at OHM SETT and is not
shown in Figure 2, but it is shown clearly in Figure 3. The oil collecting process is best
explained qualitatively by describing Figure 4, a representative flow diagram. The
overall goal is to transport oil and water through a three stage separation system
onboard. While forward speed of the vessel causes oil and water to enter the bow, the
major entry force is from suction caused by the ducted propeller intake. As they
enter, oil is skimmed using the broad-crested weir. Water flows below the weir
through a main duct, out through the propeller duct, and past a pair of reaction
rudders. Oil and water passing over the broad-crested weir is trapped in a large basin.
If debris is present it will be skimmed with the basket strainer. Once in the basin,
water is drawn through a large coke filter, past a tandern pair of adjustable sluice
gates, up an annuli, over rectangular weirs, down through annuli, through adjustable
valves, and finally into the main propulsion duct mixing with the water from the bow
entrance.
Oil is skimmed from the large basin with an adjustable basket strainer over flow
weir. It is drawn by suction into the starboard separator tank (9.65 m^). From there it
is drawn into the port-side separator tank, with another 9.65 m^ capacity. Once these
tanks are full of oil, the skimmer must be offloaded. The water passing through the
centrifugal purnp and eductors is discharged into the midship annulu, joining the water
from the large basin.
Quantitatively, the flow area is described in Figure 5, which shows the duct and
weir sizes. The centrifugal pump to discharge the port-side separator tank and power
the vacuum eductor is rated 115 m3/hour at 2900 rpm and 372 kPa (54 psi). The
vessel's propeller that provides most of the water flow is 544 mm in diameter and has
a 503 mm pitch. Revolutions are selectable based on vessel trim, forward speed, and
reaction rudder settings up to a maximum of 879 rpm. Flow through the main duct
was not stated in the Soviet Skimmer Manual but was measured at OHMSETT between
1400 m3/hour and 3700 m3/hour.
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4-1
(A
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o
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ra
0)
JI
o
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ro
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U
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IT
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Figure 3a. Debris handling system, view from bow operator's work station.
Figure 3b. Debris handling system, close up.
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y
1* -;-%" ^4%'""•""-I* •
'* *
-'
*''
Figure 3c. Debris handling system close up of chain conveyor, empty
settling basin, and coke filter entrance.
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u
o
CL
O
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u
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0)
4->
<4-
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en
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(A
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ill
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Oil
Water
Broad-crested
weir
2.19 m
Large settling
basin
19.7 m3
Coke filter
1.04 m2
Basket strainer
weir
0,5 m
S ta rboa rd
operator tank
9.6 m3
Port side
separator tank
9.6 m3
Vacuum
Sluice gate
0.13 m2
Weir
0.73 m
i
•^-
Valve
0.11 m2
eductor
(-
V—
Centrifuga
pump
Sluice gate
0.13 m'
Weir
0.73 m
Valve
0. 11 m2
Main duct
0.66 m2
p. 25
.Water
Propeller
Figure 5. Flow area of the Soviet Oil /Debris skimmer relating the duct and weir size.
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SECTION it
TEST PLAN AND PROCEDURES
TEST PLAN
The test plan was designed to simulate harbor conditions typical of the
skimmer's design environment. The USSR designed the system to be both a stationary
skimmer not requiring booms and an advancing skimmer useable to 2 knots forward
speed and a maximum of 1.5 m wave height. The OHMSETT test plan was in three
major sections to investigate the fluid flow, oil skimming in the stationary mode and
advancing mode. This skimmer was to be the largest tested, with the deepest draft,
and the first to require the propulsion system active during testing (Reference 2).
Heavy and light oil (see Appendix B) tests were required to measure pump and
oil/water separation efficiency. The Soviets were interested in the new modification
incorporating the coke filter, which necessitated the fluid flow experiments. Calm
water and wave conditions (see Appendix C) were selected to observe effects of splash
in the broad-crested weir area and the response of the vessel hull reacting to specific
wavelengths. Forward test speeds were selected to observe bow-wave interactions,
vessel trim, and bow door opening.
The skimmer operator had a wide variety of equipment adjustments for weir
height and valve positions but the pump capacities were a direct function of the main
engine shaft speed. Fluid flow was controlled by valves between starboard and port oil
tanks, and the vacuum eductor output was dependent on this flow. Advancing speed is
a function of the opening in the reaction rudders and the engine speed.
The following skimmer settings were considered important to performance
results:
Broad-crested weir angle - adjustable between zero and 90°, full open to closed.
Trim ballast tanks - zero to 60 cm, empty to full tanks (1.83 m^).
Engine speed - idle at 600 rpm to 1800 rpm maximum prudent setting.
Aft valve gate position - full open with 3 intermediate settings to close,
controlling water flow through the coke filter.
2. Lichte, H.W. and M.K. Breslin. Testing Skimmers for Offshore Spilled Oils.
In: Proceedings of the 1978 Offshore Technology Conference, Houston, Texas, 1978,
pp. 247-254.
11
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OIJ collecting weir with basket strainer - depth adjustable to correspond to the
oil/water Interface In the large basin.
Extensive photo and video coverage was utilized to document qualitative data,
vessel response, and dynamic oil/water relations. Underwater and topside 16-mm
motion pictures and 35-mm still photography was required. Remote video was
important, especially in the instant-replay mode after every test.
Measured data was recorded to calculate throughput and recovery efficiency
along with recovery rate.
Flow measurements were taken throughout the skimmer at the request of the
Soviets, so as to evaluate several of their developmental improvements in this new
model skimmer.
The OHMSETT controlled independent variables were selected based on Soviet
estimates of expected performance:
Light and Heavy test oils, slick thickness 1 to 5 mm
Tow speeds from dead in the water to 3 knots advancing.
Water conditions:
Calm
Regular waves (.4 m x 6.95 m, .2 m x 11.6 m, A m x 1.52 m)
Harbor chops (.2 m and .7 m)
The skimmer was moored between the OHMSETT main bridge and auxiliary
bridge, rigged to allow free vessel response to waves and trim conditions. Oil
collected by the skimmer, stored in its starboard tank, was transferred to the auxiliary
bridge for measuring. The main bridge oil distribution was 7 m ahead of the skimmer
bow doors.
TEST PROCEDURES
Fluid Flow
The first series of tests addressed the flow of water through the skimming
system. The Soviets were interested in specific measurements about their new
developments in the skimming system and OHMSETT was the only available controlled
environment.
The skimmer was towed in calm water the length of OHMSETT. The two Soviet
technicians operated the vessel, and three OHMSETT technicians were onboard: one
to record data, one camera man, and one to read instrument dials. The OHMSETT
Test Engineer divided his observation position among the auxiliary bridge, video
bridge, main bridge, and the vessel itself.
12
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The test procedure was to select one specific forward tow speed for a series of
engine speeds with the reaction rudders wide open. The ballast level was selected
based on the Soviet technicians' judgment for each tow and engine speed. The water
mark positions were recorded by observing the vessel pitch or trim early in the test
run.
Equipment settings, flow, and pitch of the vessel were recorded in Jog books and
by photo/video film and tape. The broad-crested weir angle was measured observing
the forward leading edge in relation to painted index marks on the wall of the large
basin. A zero angle corresponds to a horizontal weir or full open. A 90° weir is
vertical or fully closed. The ballast level was measured with a dipstick; 600 mm was
fulJ and zero was empty. Engine speed was measured with the vessel's tachometer.
Vessel trim was measured by decimeter marks painted on the large basin wall forward
and aft, designated bow box (dm) and stern box (dm). The horizontal zero position or
still water level in the stern was six and in the bow zero. The horizontal distance
between bow and stern vertical scales was 4.9 m. The procedure was to keep the bow
down, and controlled to ensure an optimum 10-cm deep oil/water skim over the broad
crested weir. The aft valve gate position was recorded to evaluate flow through the
coke filter; position one was wide open, and to position five was closed.
Water flow in the main duct was calculated using Pitot-tube manometer
measurements and the known cross-sectional area. Upwards flow in the vertical
annulus duct was calculated using direct velocity measurements from a velocimeter
and the known cross-sectional area.
Decimeter bow draft marks were painted on the vessel and bow doors to provide
the main bridge operator and Test Director a way to judge vessel trim. If improper
trim was developing, the Test Director could slow the tow speed. Decimeter draft
marks were also painted on outboard starboard side, fore, aft, and midship to provide
observations of pitch.
Skimming Oil--
The trim and fluid flow data gathered in the Flow Test section was incorporated
into the oil collection experiments and equipment settings. Performance data was also
recorded in the same manner. The Soviet-estimated skimmer design recovery rate was
12 m^/hour encountering a 1-mm thick slick. The OHMSETT test slick encountering
the bow doors was approximately 1-mm thick and 7-m wide. The majority of testing
was to be performed in this condition with several tests set aside for higher volumes to
evaluate the bow door performance. The test oil was dyed to enhance visual records.
Oil loss by the skimmer after it was encountered was recorded using photo/video
techniques.
Oil distribution from the main bridge was selected based on the 2.19-m wide
skimmer basin and broad-crested weir, the vessel preselected tow speed, a preselected
slick thickness, and the expected skimmer oil recovery rate. The main bridge oil
distribution pumps were set individually for each test based on the relation:
n - t v w
w ~ 0.274
13
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U here:
Q = oil distribution rate, m^/hour
t = slick thickness in skimmer basin, mm
v = tow speed, m/second
w = skimmer basin width (2.19 m)
0.27^ = constant for unit conversion
Main bridge observers controlled the slick width using trailing braided polyeth-
ylene rope and water jets to ensure, in most tests, that the skimmer bow doors
encountered one hundred percent of the slick. One Soviet technician/operator was
stationed on the bow to operate the broad-crested weir angle and bow door opening.
Vessel ballast was preset for test conditions, based on data from the Fluid Flow
experiments. The other Soviet technician/operator would control the engine speed,
operate the basket strainer over-flow weir, and adjust water flow values to ensure
maximum oil recovery.
The recovered oil/water was pumped from the starboard tank to the auxiliary
bridge using an OHMSETT double-diaphragm air-operated pump. As a test time saving
measure, the skimmer centrifugal offload pump was not used because of its low
capacity for pumping 7 m up to the auxiliary bridge measurement tanks.
Most of the tests were performed in triplicate before emptying the starboard
tank. This was a labor saving option in that each skimmer tank had a capacity of 9.65
rr>3 and each test would use approximately 2.5 m^ of oil. It was agreed that the three
tests arithmetically averaged would smooth out possible errors in otherwise measuring
small quantities. Each test duration was timed individually to calculate the total oil
volume encountered. The sample barrels on the auxiliary bridge were measured for
total fluid quantity, decanted water quantity, mixed for hdmogenity, and a sample
taken to the Chemistry Lab for measuring oil quantity.
The skimmer, as mentioned earlier, had some new unproven modifications.
Each of these was isolated in specific tests to determine its contribution to
performance. A wave dampener originally installed in the bow throat was removed
during the early heavy oil tests in waves (test no. 47). One repair was required when
the flapper valve in the starboard collection tank broke; the discovery came during the
offload operation (test no. 39). The outboard doors, coupling dynamic water condition
signals to the hydraulically damped broad-crested weir floats, had been enlarged for
faster response, but closing them did not visibly change the weir response in waves.
One procedure delayed to the last day of testing in light oil was removing the
coke filter panels and observing the change in fluid flow. Last in the exploratory
sequence was an experiment with the gill door opened just forward of the propeller in
the transition duct between the rectangular main duct and the round propeller duct.
The gill door was designed for use in fast forward vessel speeds not associated with
oil/debris collection. Based on our experience with skimmer gill doors we convinced
the Soviet technicians to open the door partially for several of the tests on the last
day.
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SECTION 5
TEST RESULTS
Tables 1 through 5 display the test results from the fluid flows, heavy and r'ght
oil experiments. The data columns indicate measurements described in the *'est
Procedures. The following calculations were necessary to arrive at performance
estimates:
Oil Distribution Rate, actual
Total oil distribution gallons , •*/ .
_ & x constant = m^/second
Time interval seconds
Where total oil distribution is read from a totalizer meter and time interval
read with a stopwatch.
Slick Thickness, actual
= mm
v w
Where: Q = oil distribution rate actual
v = bridge velocity from meter
w = 2.19 m, skimmer dimension
Recovery Efficiency, percent:
quantity of oil recovered by the skimmer
Total quantity of fluids recovered (oil & water)
Throughput Efficiency, percent:
™_ _ quantity of oil recovered by the skimmer
quantity of oil distributed by the main bridge
Oil Recovery Rate:
rson _quantity of oil recovered by the skimmer
"collection time of the adjustable basket weir
Main Duct Velocity:
Where K = Pitot tube constant, approx. 1.0
g = acceleration due to gravity
h = manometer reading (pressure difference)
15
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Main Duct Flow:
QMD = VMDAMD
Where:
= main duct velocity
AMD = area °f duct, 0.657 m^
Vertical Duct Flow:
QVD = VVDAVD
Where:
Vyrj = direct reading of vertical duct velocity
= area of vertical ducts, two, total 0.292
Waves; height and length
Selected from OHMSETT standard wave charts derived from spectral analysis
of a sonic wave probe. The selection is based on wave flap stroke and wave
generator rotation speed.
16
-------
TABLE 1. SOVIET SKIMMER FLUID FLOW TESTS (NO OIL)
Test
no.
i
2
3
4
5
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
19R
20
20R
21
21R
22
23
2*
25
27
28
29
Tow
speed
kt
0.5
0.5
0.5
0.5
0.5
1.0
1.0
1.0
1.0
1.0
1.5
1.5
1.5
1.5
1.5
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.5
2.5
2.5
2.5
2.5
2.5
3.0
3.0
3.0
Weir
angle
deg.
55
60
6
60/50
45
70
65
60
65
60/50
70/65
65/60
60
70
70
70
60
60
65/55
60/55
50/53
50/53
80/80
75/75
70/70
70/60
60/60
65/55
80
85
70/75
Ballast
level
mm
400
400
550
550
550
550
550
550
550
550
550
340
340
340
340
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Engine
speed
rpm
1000
1200
1400
1600
1800
1000
1200
1400
1600
1800
1800
1600
1400
1200
1000
1000
1200
1400
1600
1600
1820
1800
1000
1000
1200
1400
1600
1800
1400
1600
1800
Bow
box
dm
NA
2.5
NA
2
NA
3
3
-3
3
-3/1
4
3
3
3
3
3.5
3/3
3
3/1.5
3/2
NA
2/2
4.5/4.5
4/4
4/3.5
3.5/2.5
2.5/3
3/1.5
NA
6/5
4/4
Stern
box
dm
NA
5
NA
-5
NA
-5
-6
-5
-6
-5/4
-5
5
5
4.5
5
-6
5/5.5
4.5
5.5/4.5
5.5/5
NA
5/5.5
6.5/6.5
5/5.5
-5/5
-5/-5
4.5/4.5
5/4
NA
8.5/7
3.5/3.5
Main duct
flow
rn3/s
0.41/0.46
0.55/0.62
0.60/0.66
0.66/0/80
0.78/0.88
0.46/0.58
0.57/0.60
0.72/0.78
0.76/0.76
0.87/0.93
0.90/0.95
0.78/0.80
0.72/0.75
0.60/0.64
0.49/0.57
0.36/0.41
0.57/0.62
0.70/0.76
0.73/0.87
0.73/0.79
0.84/0.90
0.83/0.92
0.41/0.55
0.51/0.62
0.59/0.73
0.67/0.75
0.76/0.82
0.80/0.90
0.66/0.93
0.36/0.79
0.93/1.04
Vert duct
flow
m3/s
0.06/0. 18
0.09/0.47
0.50/0. 5 8
0.44/0.58
0.44/0.58
0.51/0.29
0.12/0.18
0.12/0.18
0.29/0.70
0.18/0.26
0.29/0.73
0.50/0.53
0.44/0.44
0.23/0.44
0.00/0.00
0.03/0.15
0.00/0.20
0.00/0.00
0.00/0. IS
0.09/0.21'
0.15/0.2'»
0.00/0.29
0.00/0.00
0.00/0.00
0.00/0.00
0.00/0.00
0.00/0.00
0.00/O.OA
0.00/0.00
0.23/0.29
0/0
-------
TABLE 2. SOVIET SKIMMER PERFORMANCE RESULTS - CIRCO X HEAVY OIL OF VISCOSITY 700 cst @ 23.Q°C
00
Test
no.
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51A
51B
52
53
54
55
56
Tow
speed
knots
1.0
1.0
1.0
1.0
1.5
2.0
2.0
2.0
2.0
1.5
2.0
2.0
2.0
0.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.5
1.5
1.5
Oil dist.
rate
m3/nr
10.7
10.7
10.4
21.5
37.1
50.0
0
58.3
55.6
47.0
56.2
58.1
56.9
11.8
21.2
21.5
21.3
11.8
28.0
28.3
28.5
0.0
28.6
28.5
28.6
21.9
20.4
20.6
Slick
thick
mm
2.66
2.66
2.60
5.36
6.16
6.23
0.00
7.26
6.92
7.81
7.00
7.24
7.09
0.00
2.63
2.68
2.66
2.64
1.01
1.27
1.02
0.00
1.28
1.02
1.28
1.01
1.22
0.98
Waves
ht x length
m x m
Calm
Calm
Calm
Cairn
Calm
Calm
Calm
0.36x6.95
0.36x6.95
0.36x6.95
Calm
Calm
Calm
Calm
0.36x6.95
Calm
0.36x6.95
Calm
Calm
Calm
Calm
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
Recovery
eff.
%
81.5
81.5
81.5
61.5
61.5
61.5
0.0
81.0
81,0
81.0
82.3
82.3
82.1
94.4
82.6
82.6
82.6
82.6
79.3
79.3
79.3
0.0
63.8
63.8
63.8
85.9
85.9
85.9
Throughput
eff.
%
90.5
88.7
90.6
59.0
67.1
66.8
0.0
25.5
26.7
23.7
80.9
78.1
79.8
86.6
58.4
58.4
58.0
58.0
79.6
78.8
78.4
0.0
25.6
25.7
25.6
30.7
32.9
32.8
Oil rec,
rate
m3/hr
3.6
3.2
4.1
4.7
5.3
5.3
0.0
2.8
2.8
2.8
10.5
9.7
12.4
6.1
4.6
4.6
3.2
3.2
6.7
4.2
4.2
0.0
1.7
1.5
1.5
1.9
2.4
3.4
(Continued)
-------
TABLE 2. (Continued)
Test
no.
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
7>4
75
76
77
78
79
80
81
82
83
84
85
Tow
speed
knots
2.0
2.0
2.0
1.5
1.5
1.5
1.0
1.0
1.0
2.0
2.0
2.0
1.0
1.0
i.O
1.0
1.0
1.0
2.0
2.0
2.0
1.5
1.5
1.5
1.0
1.0
1.0
•2.0
2.0
Oil dist.
rate
m3/hr
87.8
94.6
0.0
79.3
79.4
81.9
22.6
21.6
21.7
9.1
9.1
9.1
9.1
9.1
9.1
16.1
16.1
15.7
32.3
30.6
30.9
26.1
26.4
26.4
26.7
26.7
27.0
33.2
33.0
Slick
thick
mm
3.94
4.24
0.00
4.74
4.75
4.90
5.62
5.38
5.41
1.13
1.13
1.13
2.26
2.26
2.26
4.00
4.00
3.92
4.02
3.81
3.85
4.34
4.38
4.38
6.66
6.66
6.72
4.13
4.11
Waves
ht x length
m x rn
Calm
Calm
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
Calm
Calm
Calm
0.20x11.61
0.20x11.61
0.20x11.61
0.40x1.52
0.40x1.52
0.40x1.52
0.40x1.52
0.40x1.52
0.40x1.52
0.40x1.52
0.40x1.52
0.40x1.52
0.69 HC
0.69 HC
0.69 HC
0.69 HC
0.69 HC
Recovery
eff.
%
83.3
83.3
0.0
72.0
72.0
72.0
73.7
73.7
73.7
64.8
64.8
64.8
70.0
70.0
70.0
72.1
72.1
72.1
77.5
77.5
77.5
73.3
73.3
73.3
72.0
72.0
72.0
48.9
48.9
Throughput
eff.
%
70.3
65.3
0.0
36.7
36.6
28.4
56.8
59.4
59.0
110.0
146.7
146.7
38.3
46.0
46.0
64.0
64.0
65.2
58.2
61.4
60.8
51.3
50.9
50.9
33.1
33.1
32.8
15.5
15.6
Oil rec.
rate
m3/hr
8.4
8.4
0.0
5.1
6.6
5.8
4.8
4.S
5.9
3.6
6.7
6.7
2.1
2.1
1.9
5.1
5.1
4.4
6.3
8.1
5.9
4.9
4.9
5.4
4.S
5.3
6.6
' 3.1
2.2
-------
TABLE 3. SOVIET SKIMMER PERFORMANCE RESULTS - CIRCO 4X LIGHT OIL OF VISCOSITY 31 cst@22.7°C_
NJ
o
Test
no.
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
10*
105
106
107
108
109
110
111
112
Tow
speed
knots
2.0
2.0
2.0
2.5
2.5
2.5
0.0
1.0
1.0
1.0
1.0
1.0
1.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.5
1.5
1.5
2.0
2.0
2.0
1.5
Oil dist.
rate
m3/hr
34.5
32.5
33.9
44.9
41.7
42.9
11.8
16.3
16.4
16.1
16.1
16.2
16.1
34.1
32.4
32.4
145
33.5
33.0
33.0
26.1
23.8
24.8
33.6
32.5
48.6
25.3
Slick
thick
mm
4.30
4.06
4.23
4.47
4.15
4.28
0.00
4.06
4.09
4.02
4.02
4.15
.02
4.24
4.04
4.04
18.07
4.17
4.11
4.11
4.34
3.96
4.11
4.31
4.06
6.06
4.21
Waves
ht x length
m x m
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
Calm
0.20 HC
0.20 HC
0.20 HC
0.20 HC
0.20HC
0.20 HC
Calm
0.40x1.52
0.40x1.52
0.40x1.52
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
0.40x6.95
0.20x11.61
Recovery
eff.
%
50.9
50.9
50.9
33.3
33.3
33.3
51.3
50.7
50.7
50.7
37.6
37.6
37.6
45.9
45.9
45.9
36.4
56.6
56.6
56.6
40.4
40.4
40.4
43.0
43.0
43.0
39.9
Throughput
eff.
%
79.1
83.9
80.5
45.6
49.1
47.6
101.9
88.5
87.7
89.3
52.0
51.7
52.0
59.0
62.0
62.0
63.8
73.3
74.3
74.3
30.8
33.7
32.5
29.5
30.5
30.6
26.3
Oil rec.
rate
m3/hr
5.1
5.1
5.1
2.9
3.1
4.1
4.1
4.3
8.6
5.4
3.0
5.0
5.0
5.0
6.0
6.0
4.7
5.7
7.3
6.1
3.2
3.6
3.6
4.2
4.2
3.7
2.7
(Continued)
-------
TABLE 3. (Continued)
Test
no.
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
Tow
speed
knots
1.5
1.5
2.0
2.0
2.0
1.5
1.5
1.5
1.0
1.0
1.0
2.0
2.0
2.0
1.0
Oil dist.
rate
m3/hr
25.6
25.1
32.4
32.4
32.4
24.9
25.5
24.9
17
16.1
16.2
32.9
33.8
33.8
22.7
Slick
thick
mm
4.24
4.17
4.04
4.04
4.04
4.13
4.23
4.13
4.24
4.02
4.04
4.09
4.21
4.21
5.66
Waves
ht x length
m x m
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
0.20x11.61
Calm
Calm
Calm
Calm
Calm
Calm
0.69 HC
Recovery
eff.
%
39.9
39.9
42.1
42.1
42.1
41.0
41.0
41.0
52.6
52.6
52.6
59.0
59.0
59.0
19.9
Throughput
eff.
%
26.1
26.6
35.1
35.1
35.1
47.9
42.1
57.5
81.6
86.2
85.8
S5.3
83,0
83.0
8.0
Oil rec.
rate
m3/hr
3.8
2.2
2.8
2.4
2.8
3.6
3.1
3.6
6.4
10.4
4.9
5.3
5.3
5.3
1.2
-------
TABLE 4. SOVIET SKIMMER AD3USTMENTS - CIRCO X HEAVY OIL VISCOSITY 700 cSt @ 23.0 °C
NJ
KJ
Test
no.
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51A
51B
52
53
54
55
56
57
58
Weir
angle
deg.
65/65
60/60
60
60/50
60/50
35
70/60
50/70
70/57
50/45
65/60
65/65
50/70
60/60
60/60
60/60
52/57
52/57
65
55/55
65/60
50/50
60/65
60/70
60/65
45/50
45/50
40/60
65/65
55/60
Ballast
level
mm
500
500
500
500
370
70
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
160
150
160
Engine
speed
rpm
1300
1300
1600
1600
1600
1800
1600
1450
1600
1600
1600
1600
1700/1400
1700/1450
1600
1600
1850
1850
1600/1800
1450
1300
1800
1400/1300
1900
1900
1200
1200
1800/1400
1700/1300
1600/1450
Bow
box
dm
3.5/3.5
2/3
3
3/1.5
2.5
1.5
3.5/2.5
2/2.5
3/3
2/2
3/3
3.5/3.5
2/4
2.5/3
3/3
3/3
3/3
3/3
3.5
2.5/3
3.5/3
3/3
2/3
3/4
3/2.5
2/2
2/3
2/3
3/3
2/2
(Continued)
Stern
box
dm
5.5/5.5
4.5/5
5
5.5/4
5
2.5
6/5.5
4.5/5.5
6/7
6/6
5.5/5.5
5.5/6
4/6
5/6
6/7
6/7
6/6
6/6
6.5/4
5.5/6
6/6
6/6
6/7
7/7
7/7
6/6
6/7
4/7
5/5
4.5/5
Main duct
flow
ni3/s
0.39/0.49
0.44/05.7
0.53/0.69
0.62/0.69
0.62/0.69
0.66/0.80
0.59/0.66
0.62/0.73
0.69/0.78
0.55/0.76
0.80/0.83
0.84/0.89
0.80/0.95
0.59/0.95
1.07/1.10
1.07/1.10
1.04/1.44
1.04/1.44
0.84/0.96
0.80/0.94
0.75/0.93
1. 14/1. 17
0.95/0.99
1.21/1.24
1.20/1.24
0.86/0.88
0.86/0.90
0.86/1.09
1.07/1.14
J. 05/1. 13
Vert duct
flow
ni3/s
0.06/0.20
O-OO/O.!1-
0.15/0.^
0.12/0. IS
0.12/0. IS
0.00/0.41
0.09/0. 18
0.00/0.18
0.00/0.09
0.03/0.12
0.12/0. 18
0.09/0.15
0.06/0.18
0.00/0.12
0.00/0.12
0.00/0.12
0.00/0.00
0.00/0.00
0.06/0.18
0.00/0.15
0.00/0.00
0.12/0.20
0.00/0.03
0.00/0.00
0.00/0.00
0.00/0.00
0.00/0.00
0.00/0.00
0.00/0.12
0.00/0.00
-------
TABLE 4. (Continued)
Test
no.
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
Weir
angle
deg.
40/80
45/60
55/65
40/60
50.65
45/60
45/55
55/50
60/60
60/60
45/55
50/60
50/60
55/60
55/60
55/60
65/70
65/65
65/70
50/55
55/60
55/55
30/45
40/50
60/70
60/70
65/70
Ballast
level
mm
160
160
160
320
450
410
410
70
70
70
400
400
420
410
410
410
70
70
70
160
160
160
160
160
290
80
40
Engine
speed
rpm
800/1950
1300
1000
1550
1300/1200
1300/1200
1000/1100
1400
1400
1400
1400/1100
1000
1000
1200/1300
1200
1200
1700
1500/1700
1650
1350
1400/1600
1400
1300/1200
1100/800
1200
1800
1900
Bow
box
dm
2/5
1/4
1/6
0/5
1/5
1/5
1/5
2/2
3/2.5
2.5/2.5
0/5
1/5
1/5
2/5
2/5
2/5
3/4
2/4
3/5
1/4
1/4
1/4
1/4
1/4
1/5
1/5
1/5
Stern
box
dm
5/7
7/9
5/9
5/10
4/8
4/10
4/7
5/5
5.5/5.5
5/5.5
3/9
4/8
4/8
5/7
5/7
5/7
6/7
5/7
6/7
4/8
5/8
4/8
4/9
4/10
4/10
4/9
6/9
Main duct
flow
m^/s
0.15/1.30
0.55/0.60
0.49/0.55
0.33/0.84
0.41/0.55
0.33/0.46
0.36/0.49
0.36/0.39
0.51/0.60
0.36/0.44
0.46/0.72
0.29/0.51
0.33/0.62
0.21/0.36
0.15/0.36
0.15/0.36
0.87/1.06
0.82/0.98
0.88/0.97
0.55/0.67
0.57/0.67
0.60/0.70
0.57/0.80
0.57/0.76
0.84/0.00
0.73/1.09
0.87/1.23
Vert duct
flow
m-Vs
0.00/0.23
0.03/0.18
0.09/0. IS
0.03/0. IS
0.06/0.15
0.00/0. IS
0.09/0. IS
0.00/0.00
0.00/0. Of-
O.GG/Q.tn
0.03/0. IS
0.06/0.15
0.06/0.12
0.00/0.03
0.00/0.06
0.03/0.09
0.29/0. IS
0.06/0. 1.2
0.06/0.15
0.03/0. 15
0.03/0.12
0.06/0.20
0.06/0.35
0.12/0.41
0.15/0.41
0.06/0.35
0.23/0.35
-------
TABLE 5. SOVIET SKIMMER ADJUSTMENTS - CIRCO X LIGHT OIL VISCOSITY 31 cSt @ 22.7°C
NJ
4=
Test
no.
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
Weir
angle
deg.
65/60
60/55
65/55
65/70
65/60
70/65
50/60
60/55
55/55
60/55
50-55/60
50-55/60
53/51
65/60
70-55/60
65/65
70/65
65/70
60/50
65/50
52/60
50/55-60
52/60
52/60
45/52
50/57
Ballast
level
mm
60
60
60
60
60
40
40
420
420
420
300
300
300
70
70
70
60
50
50
50
50
50
50
50
50
50
Engine
speed
rpm
1400
1400
1400
1800/1900
1900
1800
1300/1400
1300/1400
1400
1400
1250/1000
1150/1000
1000/900
1550
1400
1350/1400
1400/1500
1550/1600
1550
1550
1200/1050
1100
1050
1500/1550
1600/1500
1500
Bow
box
dm
3/2.5
3/2.5
3/2.5
3.5/3.5
3.5/3
4/3.5
2.5/3
2.5/2.5
2.5/2.5
2.5/2
1/3-1/4
1/3-2/4
1/3-1/3
2/5-2/4
3/5-2/4
3/4-3/5
4/3.5
3/5-3/4
3/4-3/5
3/5-3/5
1/4-1/4.5
1/4-1/3
1/4-1/4
1/5-1/5
1/4-1/4
1/3.5-1/4
Stern
box
dm
5.5/5.5
6/5.5
5.5/5
5.5/5.5
5.5/5
5.5/5
5/5.5
5/5.5
5/5.5
5.5/5
4.5/6-5/6
5/6-5/6
5/6-5/6
5/8-4/7
4/7-5/8
6/7-5/7
6.5/6
5/8-5/8
5/7-6/8
5/8-6/8
5/8-5.5/8
5/9-5/9
5/8-4/7
5/8-5/8
5/8-5/8
5/8-5/8
Main duct
flow
rn3/s
0.70/0.86
0.75/0.80
0.70/0.80
0.95/1.09
0.93/1.01
1.04/1.09
1.40/1.52
0.25/0.44
0.00/0.00
0.00/0.00
0.29/0.46
0.00/0.36
0.25/0.39
0.78/0.80
0.90/1.05
0.95/1.02
1.02/1.04
0.90/1.06
0.95/1.04
0.99/1.08
0.00/0.93
0.00/0.89
0.00/0.88
0.69/1.15
0.00/1.12
0.25/1.06
Vert duct
flow
m3/s
0.00/0.03
0.00/0.03
0.00/0.03
0.00/0.06
0.00/0.09
0.00/0.00
0.00/0.12
0.00/0.03
0.03/0.09
0.00/0.06
0.00/0.09
0.00/0.03
0.00/0.03
0.00/0. Of,
0.00/0.06
0.00/0. 06
0.00/0.0^
0.03/0.09
0.03/0.06
0.03/0.0''
0.03/0.06
0.01/0.03
0.03/0.0^
0.01/0.03
0.00/0.03
0.00/0.06
(Continued)
-------
TABLE 5. (Continued)
N)
Ul
Test
no.
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
Weir
angle
deg.
40/55
40/52
47/60
62/760
57/70
55/70
47/62
52/62
45/60
55/55
55/55
55-50/55
65/55
60/65
60/65
52/60
Ballast
level
mm
50
50
50
50
50
50
50
50
50
450
450
450
50
50
50
50
Engine
speed
rpm
1000
1000
1000
1800/1900
1700/1650
1700
1500
1450
1500
1650
1550/1625
1600/1550
1550
1500
1600/1550
1300/1400
Bow
box
dm
1/4-1/5
1/3-1/4
1/5-1/5
3/5-1/5
1/5-1/5
3/5-1/5
2/5-1/5
1/5-1/5
1/4-1/5
2.5/2.5
2.5/2.5
2.5/2
3/2
3/3
2.5/2
1/4-1/5
Stern
box
dm
4/8-4/8
4/7-4/8
4/9-4/9
5/9-5/9
5/10-5/10
5/9-5/9
4/8-5/9
4/9-5/9
5/8-5/9
5+/5.5
5.5/5+
5+/5
5.5/5
5.5/5.5
5/5
5/8-5/8
Main duct
flow
m3/s
0.21/0.83
0.00/0.76
0.25/0.80
0.73/1.18
0.66/1.19
0.72/1.19
0.57/0.80
0.62/0.90
0.57/0.88
0.00/0.25
0.00/0.15
0.00/0.00
0.57/0.70
0.59/0.69
0.66/0.78
0.33/0.90
Vert duct
flow
m3/s
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.06/0.12
0.03/0.09
0.03/0.09
0.00/0.09
0.00/0.09
0.00/0.06
0.00/0.09
-------
SECTION 6
DISCUSSION OF RESULTS
FLUID FLOW
Fluid How measurements in the main duct were of specific interest to the
Soviets. They provided the opportunity to measure and confirm calculations in a large
test tank. Empirical calculations, while straightforward in this application, neverthe-
less depend on friction factors, degree of laminar flow, geometry, physical properties
of the fluid, propeller efficiency, and synergistic factors difficult to measure. The
results displayed in Table 1 for tests 1 through 29 imply a reasonably progressive
increase in flow up through the two knot region. Beginning at the 2.5 knot
experiments the degree of linearity becomes confusing. The manometer readings to
measure the main duct flow were steady in the calm water tests but were erratic at
high speeds and wave conditions. There was more opportunity for reading error due to
pitch and roll of the vessel, and turbulence in the main duct. Variations in the
differences of the two columns over several seconds was not uncommon. The later
stages of the light oil test series revealed problems with the Pitot tube clogging up.
The direct-reading four-cone velocimeter in the vertical duct was valuable in the early
testing, but it soon became apparent that the flow in that area was not to be increased
as expected, and the meter registered in the lower ten percent of the scale. The
stainless steel cones were well protected but bearings and the electrical connections
soon became corroded from the salt water.
The test results indicate that the vessel trim from the bow/stern box dm varied
due to ballast, engine speed, and tow speed. The skimmer operator was continuously
attempting to keep the bow down and a 10 cm skim depth over the broad crested weir.
The bow, if too low, would cause the vessel to dive dangerously and the bow doors to
submerge completely. The bow, if too high, would cause the vessel to rise thus causing
encountered oil to flow under the weir into the main duct and be lost out the propeller
tunnel.
The gate positions, while always recorded, were not changed often during the
test program. The broad-crested weir angle, a function of operator control and
turbulence from waves, proved tedious to interpret. The goal was to keep the leading
edge 10 cm below the water line, which was a function of ballast and vessel speed.
SKIMMING OIL
heavy oil tests distributed a grand total of ^1.6 rn^ during the six days. The
skimmer collected a net quantity of 66% combining all test conditions. A summary of
the fifty seven tests displayed in Table 2 showed good performance. Recovery
efficiency averaged 66% through all test conditions, dropping to a low of 48% in a .69
m harbor chop advancing at 2 knots. The best RE (85%) was in calm water at 1&
26
-------
knots, a slight crop off to 83% at 2 knots. The stationary operating mode of the
skimmer was outstanding with an RE of 9^%, using its reaction rudders and sucking oil
on the water surface from 4 m away.
Throughput efficiency best performance was 90% in calm water at 1 knot,
dropping to 80% at 2 knots. Best performance in waves (.36 x 6.95 m) produced 77% at
2 knots, dropping to 15% at 2 knots with a 0.7 harbor chop. Throughput efficiency
while remaining dead in the water and collecting the available surrounding oil pool was
86%. Maximum recovery rate as designed in the skimmer was verified to be 12.^
m3/hr.
The li|^rtj>Ll tests distributed a grand total of 39.7 TTK during the four test days.
The skimmer collected a net quantity of 61%, combining all test conditions. A
summary of the forty two tests displayed in Table 3 showed good performance for the
light oil.
Recovery efficiency averaged M% through the tow tests, dropping to a low of
19% in the worst condition a 0.69 m harbor chop at one knot. The best RE (59%) was
in calm water at 2 knots, dropping slightly to 56% in waves (.4 x 1.52 m). The
stationary test RE with the skimmer dead in the calm water while using its reaction
rudders to push the oil from around the vessel and sucking oil was 51%.
Throughput efficiency best performance was 89% in the advancing mode in
calm water at one knot. The performance dropped to 85% at 2 knots in calm water,
and 74% with regular waves (A x 1.52 m). Throughput efficiency when dead in the
water was nearly 100%. The best maximum recovery rate was 8.64 m^/hour advancing
at one knot in calm water.
Oil quantities in the port side storage tank, vertical annuli, and main duct were
too low to measure in both the heavy and light oil test phases. The mechanical
adjustments avail? le to the skimmer operator during the oil tests were selected based
on experience fro 'he fluid flow tests. Tables 4 and 5 display those recorded during
the oil tests.
Photograph " motion pictures, and video tape recorded several oil loss sources.
The major losses o curred in advancing tests when oil would be driven under the broad-
crested weir into the main duct and were quite apparent discharging out the propeller
duct. This was less obvious at slow speeds and in calm water than at high speeds and
in waves. The bow doors did not significantly cause oil loss at any of their selectable
angles. This was surprising in that they were not articulated in the vertical plane.
Oil loss was not apparent in the stationary tests. The large quantity of oil
stagnant in front of the skimmer would soon be reduced to a sheen. The suction was
great enough to cause a vortex originating at the oil surface several meters out from
the bow that then would run horizontally into the mouth of the skimmer.
27
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APPENDIX A
OHMSETT TEST FACILITY
£ -i-,"^- - *«v ' -»rL***
^/Hl!^^^
Figure A-l. OHMSETT Test Facility.
GENERAL
The U.S. Environmental Protection Agency is operating an Oil and Hazardous
Materials Simulated Environmental Test Tank (OHMSETT) located in Leonardo, New
Jersey (Figure A-l). 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 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 force up to 151 kilonewtons, towing floating equipment at
speeds to 3 meters/second for at least k5 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
28
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thicknesses a'id widths ol the test fluids can be achieved with :
by wind.
The principal systems of the tank include a wave generator and beach, and a
filter system. The wave generator and adsorber beach have capabilities of producing
regular waves to 0.7 meter high and to 28.0 meters long, as well as a series of 1.2
meters high reflecting, complex waves meant to simulate the water surface of a
harbor or the sea. The tank water is clarified by recircuJation through a 0.13 cubic
nv ter/second dsatomaceous earth filter system to permit full use of a sophisticated
u' .Twater photography and video imagery system, and to remove the hydrocarbons
t' enter the tank water as a result of testing. The towing bridge has a built-in
s' nning barrier which can move oil onto the North end of the tank for cleanup and
rt , cling.
When the tank must be emptied for maintenance purposes, the entire water
volume, or 9842 cubic meters is filtered and treated unt' it meets all applicable State
and Federal water quality standards before being disc'' 'ged. Additional specialized
treatment may be used whenever hazardous materials . ~e 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 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 Jersey 08837, 201-321-6629.
29
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APPENDIX B
OHM SETT TEST OILS
Test oils used during this test program were obtained from the Sun Oil Company
and are designated as Circo Light and Circo X Heavy. These oils are continually
reprocessed by OHM SETT to remove water and sediment that becomes entrained
during test operations. As a result, certain documented physical properties do change
over time arid use and need to be monitored. These properties and changes are
detailed in the following tables.
Since oil temperature upon distribution to the water surface quickly equili-
brates to tank water temperature, it is necessary to detail water temperature
throughout the program. Generally, this ranged from 21.1 to 23.9°C.
Interfacial tension (IFT) and surface tension were determined at 22.8°C with
tank water salinity at 8.6 ppt. Samples were collected from the oil distribution
holding tanks just prior to discharge onto the tank water surface during testing, and
after the oil collected from the tank surface by the test device had been de-watered
by the vacuum distillation unit ("after VDU").
TABLE B-l. OIL PHYSICAL PROPERTIES SOVIET OIL/DEBRIS SKIMMER
Oil
type
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Heavy
Light
Light
Light
L!fiht__
Date
sampled
5 June
7 June
7 June
8 June
11 June
12 June
13 June
1* June
15 June
18 June
19 June
20 June
21 June
22 June
25 June
26 June
27 June
28 June
Viscosity
cSt @ °C
850 (921.1
700 (322.2
850 (921.6
725 @23.8
650 (923.3
900 (922.3
1100 (921.7
750 (922.8
770 (922.2
650 @23.9
750 (922.7
725 (923.8
350 (923.8
510 (923.8
29 (922.7
33 (922.7
30 (924.4
31 (923.3
Specific
gravity
0.935
0.9335
0.935
0.935
0.935
0.937
0.9375
0.937
0.9365
0.936
0.937
0.937
0.938
0.935
0.909
0.91
0.909
0.909
Surface
tension
dynes/cm
35
35
36
36
36
36
37
42
36
36
37
37
37
37
35
34
35
35
Interfacial
tension
dynes/cm
11
12
11
11
10
13
12
13
14
13
9
11
10
10
6
5
5
6
% Water
& sediment
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
30
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APPENDIX C
OHMSETT WAVES - JO 55
The following waves were used during this test project.
REGULAR WAVES
Stroke
(mm)
114
152
38
152
CPM
26
15.
43
20
Significant
Height (1/3) (m)
0.36
0.2
0.4
0.41
Wave Length Wave Period
(m) (sec)
8.3
24.2
3
14
HARBOR CHOP
Stroke
(mm)
152
38
CPM
20
50
Significant height (1/3)
(cm)
0.69
0.2
31
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TECHNICAL REPORT DATA
(Please read /aumcrions on the reverse before completing)
1, REPORT NO.
2.
3. RECIPIENT'S ACCESSIOI^NO.
4, TITLE AND SUBTITLE
5. REPORT DATE
Performance Testing of the Soviet Oil/Debris Skimmer
6. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
8. PERFORMING ORGANIZATION REPORT NO.
H. W. Lichte
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Mason & Hanger-Silas Mason Co., Inc.
P.O. Box 117
Leonardo, NJ 07737
10. PROGRAM ELEMENT NO.
1NE826
11. CONTRACT/GRANT NO.
68-03-2642
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
John S. Farlow, Project Officer
(201-321-6631)
16. ABSTRACT
Performance evaluation of a Soviet oil skimmer was conducted at the United States
Environmental Protection Agency's Oil and Hazardous Materials Simulated Environ-
mental Test Tank in 1979. The skimmer was provided by the Black Sea Central Plan-
ning and Designing Bureau, Odessa. The test program was designed at OHMSETT to evalu
ate the oil skimming capability of a specially modified Soviet skimmer, Model 2550/4.
The self-propelled vessel is 17.7 meters long and weighs 39 metric tons. The 111
kilowatt diesel engine drives a ducted propeller water jet propulsion system. The
vessel is capable of five knots forward speed and skims effectively at speeds from
zero to two knots.
The unique combination of various weir designs into one system, vessel mobility,
the efficient use of energy, a series type oil/water gravity separator, and the pro-
pulsion techniques all suggest it to be an effective harbor skimmer. The oil
recovery rate of 12.4 cubic meters per hour was confirmed using OHMSETT heavy test
oil (1.5 pascal seconds and 0.95 specific gravity) in calm water conditions. Recovery
efficiency was 85 percent at 1.5 knots forward speed and throughput efficiency was 90
percent at one knot forward speed. Performance dropped for skimming light oils at
faster speeds and higher wave conditions. The skimmer collected 64 percent of the
81.3 cubic meters oil volume encountered during the test program.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Performance Tests
Skimmers
Water Pollution
Oils
Spilled Oil Cleanup
Protected Waters
Coastal Waters
3. DISTRIBUTION STATEMEN1
Release to Public
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
41
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
32
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