OBSERVATIONS AND RECOMMENDATIONS
FOR THE PREVENTION OF OIL POLLUTION
WORKING PAPER NO. 81
Prepared by
Richard A. Wagner
June 1970
Federal Water Quality Administration
501 Pittock Block
Northwest Region
Portland, Oregon 97205
June 25, 1970
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OBSERVATIONS AND RECOMMENDATIONS
FOR THE PREVENTION OF OIL POLLUTION
INTRODUCTION
Background
The prevention of oil spills and the control of oily discharges
are of great importance to the oil industry and regulatory agencies.
Control measures are an absolute necessity, not only because of the
adverse effect spilled oil has upon the aquatic environment, but also
because of the values the refined products represent. In addition,
to fuel and lubricating products, many valuable fay-products are re-
covered and/or manufactured from the world's crude oil. These by-
products include waxes and paraffins which are increasing in value.
Raw crude oil is a very complex, heterogeneous mixture of many
forms of carbonaceous materials. Crudes such as Sumatran or Persian
Gulf are very viscous because of the tar and asphalt content. These
crudes must be kept heated in order to be handled. Alaskan crude
has a very low tar and asphalt content and can be handled easily at
50°F. The wax and paraffin contents of Alaskan crude are relatively
high, being less dense than sea water and float on the water surface.
The tars and heavy asphalts in crude oil, being more dense Cspecific
gravity 1.2) than sea water, will sink as they separate from the
waxes and paraffins and the volatile fractions evaporate.
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Problem
Presently the methods, procedures, and techniques employed by
the oil industry for the handling and marine transporting of crude
oil are largely unknown outside of the industry. These must be fully
understood by the regulatory agencies in order to assist the oil
companies in the control and prevention of oil pollution.
Authority
At the request of the Commissioner, Federal Water Quality
Administration (FWQA), arrangements were made through Hendy Inter-
national Company for a representative of FWQA to board the SS ATLANTIC
ENGINEER and observe crude oil handling techniques and ship operations
at sea. The FWQA observer boarded the ship when it docked at Terminal
Island, California, on April 29, 1970, and remained aboard until it
arrived at Homer, Alaska, on May 6, 1970.
Objective
The objective of this trip was to answer the following questions
regarding marine transportation of crude oil with particular emphasis
on potential or observed oil pollution problems.
1. What are normal ship operations procedures relative to
scheduling, crew changes, etc?
2. What are the procedures used for handling crude oil?
3. What ballasting procedures are used?
4. What procedures are used during tank cleaning operations?
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5. What new or improved techniques, methods, procedures, or
processes must be employed or included to prevent oil
pollution?
Acknowledgment
The friendly cooperation and assistance of Atlantic Richfield
Company and Hendy International Company is gratefully acknowledged.
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APPROACH
Answers to the above questions were obtained from visual
observations of cargo handling procedures, ship operations, conversa-
tions with key crew members, and discreet analysis of pertinent oil
or water samples.
The above findings are presented and discussed below in four
major categories. These are:
1. General ship operations, ship operating procedures, schedules,
sailing routes, and manning procedures;
2. Cargo handling procedures;
3. Ballasting practices and procedures;
4. Tank cleaning procedures.
General Ship Operations
Schedules and Operations
In general, the industry considers crude oil carriers as tankers
and refined product carriers as chemical ships even though, the over-
all design is the same. Many tankers under U. S. registry are
managed, scheduled, and operated for the owners by a consulting firm;
for example, Hendy International Company performs these services for
Atlantic Richfield Company. Turn-around time is minimal because the
derived profits are based upon the amount of cargo delivered in the
shortest possible period of time. In general, the places for loading
and off-loading cargo are known and scheduled well in advance, and are
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based upon the normal cruising speed of the individual vessel, the
ship's capacity, and the capability of the shore facilities.
Routes
Most West Coast tanker traffic between California and Pacific
Northwest ports is seldom farther than 10 to 12 miles offshore.
Prevailing westerly winds will soon move any discharged floating
materials upon the beach without too much dispersion. Floating
materials discharged at least 50 miles offshore will take a longer
period of time--if at all—to reach the West Coast—and will be much
more dispersed by the time they reach the coast.
Most West Coast-Alaska traffic is found in one of three well-
defined sea lanes. These sea Janes are shown in Figure 1. It can
be noted from Figure 1 that all ships including those going to and
coming from Alaskan Ports are relatively close in shore between any
California port and Cape Blanco. No deballasting or bilge discharging
should be permitted in the above area because of the close proximity
to shore and resultant hazard to sea birds and other forms of aquatic
life.
On the San Pedro (Terminal Island) to Nikiski, Alaska, run
typical daily noon positions follow:
First day out, 40 miles west of Monterey, California course 321°T
Second day out, 150 miles west of Crescent City, California
Third day out, 510 miles west of Grays Harbor, Washington
Fourth day out, 141°W 52°N
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Fifth day out, 146° 10'W 56° 20'N
Sixth day out, Mikiski or Drift River, Alaska
Manning
The crew signs on for three-month periods. The officers are
salaried, but the remaining portion of the crew is paid on an hourly
basis for actual time of work. Relief crews are used to operate
the ship in the most frequent ports-of-cal1 on the West Coast thus,
the crew which actually rigs the gear, and connects and disconnects
the hoses may be unfamiliar with each ship's peculiarities or exact
modus operendi. This creates and increases the possibility of oil
spills from the hoses or faulty connections. No orientation re-
garding their duties is given and their assigned tasks are accomp-
lished by trial and error.
Cargo Hand!ing Procedures
Tanks and Pipery
The tanks are numbered from forward to aft and are designated
as port or starboard wing, or center. The wing tanks are usually less
than half the size of the center tank in a row. As example, on the
SS ATLANTIC ENGINEER the capacity of each wing tank is about 5,000
barrels, and the capacity of each center tank is about 13,000 barrels.
In most tankers the outside and the bottom of the tanks are the hull
of the ship. A hole in this part of the ship is automatically a hole
in a tank. A hull rupture allows the tanks' contents to escape to
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open water.
The main cargo pipeline has a diameter of 20 inches. This line
feeds three 16-inch pipelines each one of which runs fore and aft
through a row of tanks. The tanks' 16-inch main line is twelve feet
off the bottom and is fed by a 10-inch pipe (called a stringer) that
extends downward for 8-feet. The open end of the stringer is four
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feet off the bottom. Thus, the material remaining in the bottom of
the tank is four feet deep and cannot be removed by conventional
means. Some tankers are equipped with smaller diameter pipe line
which are installed on the bottom of the tanks. This facility is
used to strip the remaining material (sludge) from the tank. It may
then be transferred and stored in one of the after cargo tanks which
are designated for sludge storage purposes.
Cargo Discharge Practices
The gear and hoses are rigged and connected by the deck force
under the direct supervision of the boatswain. The cargo is handled
by the pumpman who also assists the desk force in connecting the
hoses to the ship's cargo pipe line. Both of these operations are
under the overall supervision of the mate on duty who may not be
sufficiently familiar with the finite operations of the ship or
aware of his responsibility to prevent oil spills.
On the Atlantic Engineer the ship's boom is used to lift the
two T2-inch diameter rubber hoses aboard and to connect them to the
20-inch diameter cargo pipeline by a flanged "Y" fitting. After the
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connections are inspected by the mate, the pumpman is ordered to
commence discharging cargo from the most forward set of tanks. At
times, drips and leaks at these connections and during hook-up
and disconnecting operations are ignored allowing the oil to accumu-
late on deck or possibly to spill over the side if the situation is
not corrected. Cargo discharge can proceed without interruption.
As one tank is emptied the valves to the next one are opened and dis-
charge continues. In general when taking on cargo the tanks are
filled from aft-forward.
Entries regarding the handling of crude oil are made in the
ship's smooth log as well as in the oil log. The completeness of
these entries is extremely variable between different ships as well
as different masters and mates. As example, the logs on one ship
may contain information relative to when the hoses were connected,
when cargo discharge was commenced, the pumping rate, if there
v/ere any leaks or similar problems, when cargo discharge was completed,
when the hoses were placed ashore, and the names of the mates on
duty at the time of the entry. On the other hand, these could be
a single entry by date - noting that cargo was being discharged and
the entry could be signed by the chief mate and an oil company
employee. The oil company employee signs for the company showing
the ship discharged and the shore side facilities received a noted
volume of crude oil.
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Ballasting Procedures
General Practices
Ballast water is taken aboard by the use of the cargo pumps
(induction system) and put in preselected tanks under the supervision
of the chief mate, upon orders of the master. There are three different
layers of material in a dirty ballasted tank. The top layer - "slop" -
contains the remaining light fuels, oils, greases, waxes and paraffins.
Analysis of a slop sample from No. 4 port tank revealed a total oil
concentration of 10,200 ppm. The middle layer is sea water and
dissolved and emulsified oils. The ballast water held in No. 4 port
tank had a total oil concentration of 2,800 ppm. The bottom layer -
sludge - contains tars, asphalts, sand, and rust.
Not all of a ship's tanks are used for ballasting, but all of
the tanks that are used are filled completely. Sea water and sludge
are in the bottom 4 feet of the tank after ballasting.
Each master has his personal tank combination for ballasting
under normal conditions at sea, and his own method of operating
the ship under various conditions of sea and weather. Thus, when
a tanker is in heavy weather the master can slow down and/or take
on more ballast by filling additional tanks. When the weather has
moderated the master can increase his speed and/or discharge the
additional ballast. When this is done, most of the sea water
ballast and slop are discharged over the side from ships that do
not have stripping lines and store the slops in designated tanks.
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These slops float on the water surface in the tank and are discharged
in a slug.
Slop, sea water, and dissolved and emulsified oils are discharged
over the side by either gravity and/or pump when deballasting and
without exercising due regard or caution. The slops which float
on the water create a hazard to waterfowl and other forms of water-
oriented wildlife. The dissolved and emulsified oils are also a
hazard to fish, plankton, and other forms of aquatic life. In order
to prevent damage to aquatic-oriented organisms, the slops and
ballast waters should be discharged to shore holding and treatment
facilities.
The State of Alaska Water Quality Standards regarding the
discharge of oily material allows no visible film or slick created by
the effluent (discharged wastes). The State of Washington Water
Quality Standards allow the discharge of an otly effluent with less
than 10 ppm total oils.
The ballast water on the SS ATLANTIC ENGINEER would have had to
be diluted 280:1 before it would meet the State of Washington mini-
mum water quality effluent standards.
The general attitude (lack of due regard) on the part of the
pumpman is another reason oily wastes are discharged near shore
or in confined waters. Dirty ballast water could be discharged
at sea but unless the pumpman was careful during ballast discharge
he could also allow the slops to be discharged. The master may be
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on a new route in unfamiliar waters and not familiar with the laws
concerning the discharge of oily wastes. These oily wastes are
just as damaging to the aquatic environment as the materials which
are accidently spilled.
It is reported most shore installations do not have facilities
to handle ballast. Shore installations that do have ballast and
slop storage and treatment facilities usually do not have adequate
capacity to properly store and treat these wastes. Because of this,
most tanker captains are forced to discharge their ballast and slop
at sea. Adequate receiving, storage, and treatment facilities must
be provided to eliminate the necessity of discharging dirty ballast
to open or confined waters.
Tank Cleaning Procedures
Stripping
The two main oil loading facilities in Cook Inlet are at Drift
River and Nikiski, Alaska. The quality of the crude oil at these
two depots is very similar except for the amount of contained sand.
As has been mentioned above many tankers, such as the SS ATLANTIC
ENGINEER, do not have stripping lines in the bottom of the tanks;
thus, their tanks cannot be emptied completely. Cargo tanks on the
SS ATLANTIC ENGINEER are cleaned every third trip from Drift River
and every other trip from Nikiski to remove the sand and sludge
residues. On tankers with stripping lines the sand and sludge
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residues are transformed to certain designated tanks, stored, and
discharged ashore for processing. The cargo tanks on these ships
require much less frequent cleaning.
Butterworthina
A unique double-nozzled hydraulic appliance called a "Butter-
worth" is used to clean tanks. The angle of the movable nozzles
on this apparatus are balanced and opposite which allows each nozzle
to move through the full 180 degrees of a hemisphere. The ships
fire pumps are used to supply tfie required amount of sea water at
165 pounds per square inch pressure used for washing the tanks.
Butterworthing takes about four hours at sea and 8 hours at the
dock. One reason for this difference in cleaning time is the amount
of dilution water available and the size of the dispersion zone.
Another possible explanation is that in port because of the fire
hazard port authorities and shipyards require extra clean tanks to
prevent accidents.
The tanks are normally washed at four levels from the top down.
About one-half hour is spent washing the top level and about one and
one-half hours are spent washing the lowest level. The flow of
water through the Butterworth is about 500 gallons per minute.
Occasionally some additives are used but their amounts are reported
to be minor. The sludges are much more viscous than the slops
and require more water and time for them to be scoured from the tank
bottom.
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The Butterworthed washings are sucked from the tank and dis-
charged over the side by the cargo pump (main induction system),
which has a flow of about 6,000 gal. per 1 min. The diluted
continually discharged tank residues probably cause a sheen, or
film but this should not be a hazard if done in the above manner
and in the open ocean. A definite hazard to seabirds and other
aquatic life would be created if the Butterworth wastes were dis-
charged in intermtttant slugs. This is entirely possible since
the flow ration between the main induction line and the Butterworth.
unit is 12:1.
After the tank has been cleaned completely on the SS ATLANTIC
ENGINEER a four foot deep pad of sea water remains in the bottom of
the tank. This remaining sea water (occupying about 7 percent of
the tank volume) is mixed with crude oil when the cargo is taken
aboard. Some of this sea water will mix with the lighter fractions
of the crude but the heavier crude oil fractions and sand will sink
to the bottom of the tank.
Normally, tanker crews on the Alaska run start to clean the tanks
the second day out of port if the ship is beyond the 50-mile limit
or continental shelf. "Coasters" that clean thefr tanks at sea
and do not get that far offshore probably start cleaning their
tanks as soon as they reach the open ocean. Many near-shore oil
spills are probably created by this method of ship operation. The
only way oil pollution can be prevented in coastal waters is for
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all ballast, slops, tank cleanings, and bilge materials to be dis-
charged to adequate shore facilities.
In conclusion oil pollution can be controlled and/or prevented.
The causes and sources of oil pollution are poor and/or inadequate
gear and equipment and/or carelessness during certain ship's opera-
tion.
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RECOMMENDATIONS
The following specific recommendations regarding procedures,
techniques, and equipment should be implemented to prevent and
control oil pollution from marine sources.
Equipment
1. Develop gear and equipment specifically to be used for
handling cargo hoses. This could be in the form of cradles, straps,
slings, etc. with a fish davit in place or special booms used to
bring the hoses aboard.
2. Install "quick, shut-off" valves on the ship end of the
cargo hoses.
3. Install a tank stripping system in the bottom of the tanks.
4. Construct new or increase the size of existing shoreside
facilities at all on and off loading facilities for storing, handling,
and treating all slops, sludge, bilge, and ballast wastes.
5. Install oil collecting pans Ctrays) and traps under each
hose connection.
6. Design and install a device in the cargo tank which will
keep the oil and ballast water completely separate.
Operating Procedures
1. Use some of the cargo tanks for storing slops and sludge.
2. Butterworth effluent should be discharged only to the open
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ocean beyond the Continental Shelf, or in port to a shore treatment
facility.
3. Require the oil and ship's logs to be kept and maintained
in a more detailed manner. All ship operations including slop
handling, ballasting, and tank cleaning should be entered in detail.
This includes which tanks were used for ballast purposes, the fore
and aft drafts of the ship, how the ballast was discharged, length of
time this operation took place, and the location of the ship when this
was being done. Each major entry should be initialed by the mate
on watch.
4. Use certain tanks for ballasting only and provide sensor
controls with warning system which would warn the mate and pumpman
of slop in the line, shut off the individual tank valve, and stop
the over the side discharge of slop.
Other
1. Use loss of pay as incentive to create a more careful
working attitude among the crew.
2. In addition to the master, the firm in charge of operations
should be financially responsible for oil pollution.
3. Conduct a vigorous public relations campaign directed at
informing the crew and the operators of shoreside facilities that
oil spills can be prevented.
4. Vigorously enforces the public laws and company policies
for the prevention of oil drips, oil leaks, and oil pollution from
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spills.
5. Distribute a digest of the present and future oil pollution
prevention laws and regulations through "Notice to Mariners".
6. Help prevent ship collisions at sea by designating discreet
portion of the sea lanes for one directional traffic. "Near misses"
or instances of disregard for the observance of the Rules of the
Road should be reported to the appropriate authority.
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SUMMARY
Oil pollution can be prevented or controlled by the following
means:
1. Require and provide the necessary equipment.
2. Require better oil handling techniques.
3. Require adequate handling, storing, and treatment facilities
ashore.
4. Require that all oily material be discharged to shore
facilities.
5. Extend the area of responsibility to include more individuals.
6. Tighten the regulations governing all oil spills.
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