Unit II
PREVENTION OF MARINE
POLLUTION FROM SHIPS
Chapter 5
Preventing Marine Pollution from Ship
Operations
Outcome:
• Identify various ship operations generating
pollutio...
Introduction
In order to avoid marine pollution from ships,
activities on board vessels should be taken with
extreme care....
SHIPS OPERATIONS GENERATING POLLUTION
The common causes of pollution from routine shipboard
operations are as follows:
• S...
BUNKERING
-the operation of taking on board fuel.
- in most cases, bunkering is a major cause of operational oil
spills fo...
MEASURES TO PREVENT OIL SPILL DURING OPERATIONS
a. Fitting of scupper plugs and checking that drain plugs of
bunker, manif...
g) Barge/ shore tank sounding and/or meter readings should also
be checked before and after bunkering to help resolve any
...
TRANSFERRING OF FUEL
-Transferring is done either within the ship or from ship-to-ship
transfer operations.
Ship-to-ship >...
d) All pieces of equipment must be in good condition, this includes
the hoses, couplings, etc.
e) Experienced personnel wh...
For the purpose of monitoring discharge of oily bilge water and
oily ballast water from fuel tanks, installation of oil fi...
The equipment requirements for oil-water separating equipment
and oil filtering equipment are as follows:
a) Oil-water sep...
The equipment requirements for oil-water separating equipment
and oil filtering equipment are as follows:
shipboard operat...
TANKER OPERATIONS
Tankers carry a variety of petroleum products. Tankers are
considered as the single largest contributor ...
In this regard, it is extremely important that all loading and
unloading operations are done with all the necessary
precau...
STANDARD SAFETY PROCEDURES FOR TANKER
OPERATIONS
The standard safety proceduresin the following tanker operations
are norm...
iii. Fire fighting equipment and gears are placed close to the
manifold and ready for immediate use. Measures are taken
to...
v. …installation should be shut off. The gases in the tanks are
blown out during loading and dislodged by cargoes.
B. Duri...
iii. if sheer forces and bending moments reach the maximum.
If so, steps are to be taken to reduce them. Near the end of
l...
iii. All openings of the tanks are closed gas tight, except P/V
breakers. The whessoe gauges are to be raised up to the
st...
iii. The inert gas is started
iv. The pumps are ordered and stand by until discharging is about
to start. After short gate...
Tank cleaning and installation of fittings for tankers
Tankers are equipped with tank washing machnes. These may be
portab...
The following procedures are followed when loading on top:
a. The tanker arrives at the port of destination fully laden an...
g. At the loading port, oil is loaded into the cargo tanks on top of
oil remaining in the slop tank.
MARPOL 73/78 requires...
COW was used as an alternative to the Segregated Ballast Tank or
SBTs for existing tankers at that time, as required by MA...
C. Sewage treatment plant
>sewage is one of the marine pollutants coming from ships.wastes
and fuel residues consists main...
C. Sewage treatment plant
the sewage treatment plant or comminuter or the holding tank
should be in accordance with standa...
SUMMARY
i. There are various operations on board ships that generates
marine pollution. These are bunkering, cargo loading...
End of Chapter 5
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Presentation chapter 5

  1. 1. Unit II PREVENTION OF MARINE POLLUTION FROM SHIPS
  2. 2. Chapter 5 Preventing Marine Pollution from Ship Operations Outcome: • Identify various ship operations generating pollution • Distinguish tank operations resulting in pollution • State the hazards involved in handling petroleum; and • Explain safety measures in handling petroleum cargo.
  3. 3. Introduction In order to avoid marine pollution from ships, activities on board vessels should be taken with extreme care. Lack of safety measures increases the chance of spilling oil or harmful substances. This chapter deals with ship’s operational activities that generate marine pollution. Emphasis on standard safety operating procedures in the handling of petroleum cargo is given in this chapter
  4. 4. SHIPS OPERATIONS GENERATING POLLUTION The common causes of pollution from routine shipboard operations are as follows: • Ships taking in or transferring bunkers or disposing of or transferring fuel, fuel residues and oily bilge water • Tanker operations such as cargo loading/discharging, tank cleaning, ballasting operations • Discharge of hold bilges or ballast water on vessels other than tankers • Washing of decks covered with cargo remnants or hydraulic oil which has leaked from deck machinery • Discharge of sewage • Disposal of galley and other garbage
  5. 5. BUNKERING -the operation of taking on board fuel. - in most cases, bunkering is a major cause of operational oil spills for all types of vessels. The ship’s officer-in-charge of monitoring this task has to be alert and experienced in this field. The areas of safety concern are as follows: • The position of overflow and air pipes • Overflow tank and sounding pipes • Depth indicators of all fuel tanks • Overflow alarm system
  6. 6. MEASURES TO PREVENT OIL SPILL DURING OPERATIONS a. Fitting of scupper plugs and checking that drain plugs of bunker, manifold and fuel tank air pipe containment “save- alls” are in place b. Establishing communication with supply control position and agreeing on maximum pumping rate and pressure. Ensure that any signals to be used are thoroughly understood c. Checking the conditions of hoses and couplings before and during bunkering. d. Checking blanks available and hose string of sufficient length to allow for normal for normal movement of vessel. e. Checking all valves in required position and tank vent pipes free from obstruction before bunkering commences. f. Taking accurate sounding of all tanks before and on completion of bunkering in oreder to verify the amount of fuel delivered.
  7. 7. g) Barge/ shore tank sounding and/or meter readings should also be checked before and after bunkering to help resolve any problem concerning quantity. h) Taking frequent sounding during bunkering and rate of delivery slowed down during topping of. i) Ample warning should be given to supplier of need to reduce delivery rate and the final shutting off. j) Vessel should be upright and even keel throughout the bunkering operations.
  8. 8. TRANSFERRING OF FUEL -Transferring is done either within the ship or from ship-to-ship transfer operations. Ship-to-ship > transfer or lightening may occur either in a port area or at sea If transfer is from one ship to another ship, risk is also considerable. Safety measures should be undertaken to prevent the release of oil into the water. The measures are as follows: a. Fenders are properly placed when a vessel is to be positioned alongside the damaged vessel for the transfer of oil (in case of salvage operations) b. Before transfer begins, a lightening plan must be detailed so that vessel shall stay at even keel. c. Clear languages or communication instructions and signals must be adopted by both ships.
  9. 9. d) All pieces of equipment must be in good condition, this includes the hoses, couplings, etc. e) Experienced personnel who have the skills in the delicate operations must be deployed. f) Emergency procedures must be adopted by both vessels. BILGE WATER DISCHARGE OPERATIONS AND EQUIPMENT REQUIREMENTS >Bilge water discharge should be done to shore facilities. However in order to discharge water from bilges at sea, a series of conditions are provided by technical Annex I of MARPOL 73/78. For the purpose of monitoring discharge of oily ballast water or tank washings from cargo tanks, installations of an oil discharge monitoring and control system is required together with fitting of oil/water interface detector.
  10. 10. For the purpose of monitoring discharge of oily bilge water and oily ballast water from fuel tanks, installation of oil filtering equipment is required. Different equipment should be attached to oil-filtering equipment depending on the gross registered tonnage of the ship. Regulation 14 of the revised Technical Annex I reuires that any ship off 400 GT and above but less than 10,000 GT shall be fitted with oil filtering euipment, which design is approved by the administration. It should be noted before the revision of technical Annex I of MARPOL 73/78, the oil filtering equipment requirement was within Regulation 16 of Technical Annex I
  11. 11. The equipment requirements for oil-water separating equipment and oil filtering equipment are as follows: a) Oil-water separating equipment – It may include any combination of a separator, filter, or coalescer and also a single unit designed to produce an effluent with oil content of less than 100ppm. b) Oil filtering Equipment- It includes any combintaion of a separator, filter or coalescer and also a single unit designed to produce an effluent with oil content no exceeding 15ppm. It is intended to use equipment attached to oily-water separating equipment certified for an effluent of less than 100ppm The following are the regulations relative to fitting the filtering equipment: • When the level of effluents discharge more than the required 15ppm, the bilge alarm system activates. • The oil filtering equipment should be strongly suited for
  12. 12. The equipment requirements for oil-water separating equipment and oil filtering equipment are as follows: shipboard operation. • It is fitted in areas where flammable atmosphere may be present • Electrical support attachment should be equipped with safety equipment and installed in the safe areas. • The equipment is designed to function automatically but manual control is also provided in case of emergency. • The system should be able to operate at least 24 hours of normal duty without attention. • The bilge alarm has an oil content meter. The meter can withstand corrosion arising from saltwater. The meter is fitted with an alarm device, which is set automatically to alert crew of the ship. The alarm activates when the effluent exceeds 15ppm. The alarm also operates automatically when the meter fails to function during a warm up period or de-energized.
  13. 13. TANKER OPERATIONS Tankers carry a variety of petroleum products. Tankers are considered as the single largest contributor of marine pollution. The introduction of supertankers created public concerns in both developing and advanced countries. Oil pollution from tankers originate from two principal sources. These are as follows: 1. Various types of tanker accidents. 2. Normal tanker operations(i.e. tank cleaning, ballasting, and other operational activities involving discharge of oil overboard) Aside from the tanker accidents and normal tanker operations, the dry-docking activities of these types of ships also add to the oil pollution. However, the normal tanker operation is considered as the main source of marine pollution from tankers.
  14. 14. In this regard, it is extremely important that all loading and unloading operations are done with all the necessary precautions. This practice reduces the risk of unnecessary oil release into the water that pollutes the sea but also ascertains that lives and properties are not endangered.
  15. 15. STANDARD SAFETY PROCEDURES FOR TANKER OPERATIONS The standard safety proceduresin the following tanker operations are normally followed to avoid accidents that may entail marine pollution: A. Pre-loading Operations i. Before loading, a communication and signaling system should be agreed upon between the ship and shore personnel. For a standard ship, a shore safety checklist is used and the items on it are checked. ii. A loading plan is drawn between the ship and the shore wherein loading sequence, stoppages, etc. are stated. The ullage is calculated to which the cargo is to be loaded
  16. 16. iii. Fire fighting equipment and gears are placed close to the manifold and ready for immediate use. Measures are taken to prevent oil from flowing overboard in case of leakage of hose couplings, etc. the tank lids are closed gastight and the tank vent risers are put in loading position. iv. The ullage meters are lowered to their lowest position. The ships cargo lines are set right as in the case with tank valves. If only one product is to be loaded, the valves in the main and the crossover lines may all be kept open. The suction and discharge valves of all pumps are shut. v. The cargo line valves in the pump room are to be set right. The terminal will connect their lines to the ship’s manifold by means of hoses or steel pipes. After all the checking, the ship can indicate to terminal that their valve/s now may be opened and loading can start. The time the ship is ready to load is noted on time sheet. Inert gas installation should be
  17. 17. v. …installation should be shut off. The gases in the tanks are blown out during loading and dislodged by cargoes. B. During Loading Operations i. Loading should start slowly to check if connections are oil tight and also to avoid static accumulation. Checks should be made if oil flows overboard via the seachests in the pump room and the cargo in indeed flowing into the tanks. ii. The speed of loading may rise gradually to an agreed speed or allowable hose or chicksan pressure. Soon after loading has begun, the terminal and ship will take samples of the tanks that are being loaded to check the temperature of the product. iii. During loading,rounds are made regularly to check the moorings, emergency, towing wire, etc. the loading speed is checked. The calculated ullage is checked if nearly reached. The tank valve is closed. The regular intervals are checked
  18. 18. iii. if sheer forces and bending moments reach the maximum. If so, steps are to be taken to reduce them. Near the end of loading, speed must be reduced to diminish the chance of an overflow from the tank, as this may entail a heavy fine on ship. C. POST LOADING OPERATIONS i. After completion of loading, the ship’s manifld valves are only to be closed after the shore valves have been closed. The tank valve is to be closed last. After completion of loading, the hoses or loading arms should be emptied into a drip tray prior to disconnecting. ii. After disconnecting the hose and loading arms, blind flanges are to be connected to the manifold valves. All main and crossovers valves are shut.
  19. 19. iii. All openings of the tanks are closed gas tight, except P/V breakers. The whessoe gauges are to be raised up to the stored position D. DISCHARGING OPERATIONS i. Of every cargo tank, the ullage, density, and temperature of the cargo is to be taken and the tanks are water dipped. The sip and terminal representative or an independent cargo inspector on behalf of the receiver does this. Thereafter, the quantity of cargo is calculated. ii. Hoses or chicksans are connected. Then, tank ventilators are opened and the pump room is freed of gas. After this, the necessary valves in the pump room can be opened. During discharge, the ventilators of the pump room must be kept going. The necessary cargo lines and terminal valves are opened.
  20. 20. iii. The inert gas is started iv. The pumps are ordered and stand by until discharging is about to start. After short gate valve is opened, the ship manifold valves may also be opened and discharging can start. v. During discharging, the same measures as in loading can be undertaken to ensure safety. vi. When the liquid level is low, the dischargespeed must be slowed down to darining speed. A grumblling sound heard from the tank means that it is nearly dry. To drain wing tanks the ship may be given a list of the suction valves and their location. vii. After all tanks are drained, tank dips are taken in the presence of terminal inspector n behalf of the receiver of cargo and the quantity left on board is calculated. After discharging is completed, hoses and loading arms are disconnected and all other connections are removed.
  21. 21. Tank cleaning and installation of fittings for tankers Tankers are equipped with tank washing machnes. These may be portable or mounted in the cargo tanks. The conductivity must be checked every time before it is used and lowered to a butter hole into a tank. Some of the regulations concerning installations pertain to the following: A. Slop tanks >the purpose of the slop tank is to separate, as much as possible, water that has been introduced into tank washing during and during ballast voyage, from the oil that is removed from tank. The contents of slop tank, after tank washing and pumping out unpolluted water, consist of oil, water-oil emulsion and some water. Load on Top- when the cargo is loaded while the hold still contains slops. Introduced in 1960, which contributed significantly to the reduction of oil pollution from tankers. The load on top regulation was made mandatory under MARPOL 73/78.
  22. 22. The following procedures are followed when loading on top: a. The tanker arrives at the port of destination fully laden and ready to discharge its cago. b. After discharging the cargo, quantities of oil remain clinging to the sides of the tanks. c. The ship has to fill some of its tanks as ballast water return voyage. d. These tanks has to be washed and the slops are pumped into a tank. e. Ballast water is pumped into some of the cleaned tanks. The dirty ballast tanks are cleaned and the slops are pumped into the slop tanks. f. While on return voyage, the oil and water in the slop tank separates. The oil floats to the top and water under the oil is carefully pumped into the sea.
  23. 23. g. At the loading port, oil is loaded into the cargo tanks on top of oil remaining in the slop tank. MARPOL 73/78 requires that oil tanker of 150 tons gross tonnage and over be provided with oil-water interface detectors for use in slop tank and other tanks, where separation of oil and water is effected for discharge to the sea. B. CRUDE OIL WASHING (COW) and the Inert gas System MARPOL 73/78 requires crude oil washing for tankers of 20,000 deadweight and over to be equipped with COW system. COW was introduced in 1970s. This system allows the cleaning of tank from sludge with crude oil itself. Thus, under COW system, tanks are washed not with water but with crude oil or the oil cargo itself because the best solvent for sludge is the crude oil.
  24. 24. COW was used as an alternative to the Segregated Ballast Tank or SBTs for existing tankers at that time, as required by MARPOL 73/78. if the ship has COW, it must also be equipped with an inert gas system before washing begins, the tank must be monitored for the quantity of gases and oxygen. During operation, the pressure on inert gas system must be higher than the suction pressure of pump with which the tank is discharged or drained. It is noted thatinstead of using seawater,tank cleaning is done by jet spraying the cargo tanks with crude oil itself, which has been proven by experts as a better cleaning agent than water alone. The consignee of cargo also benefits from this technique because no oil wasted in cleaning the tank. In the previous technique, when oil and water mixture is used a proportion of oil cargo is wasted when mixed with water
  25. 25. C. Sewage treatment plant >sewage is one of the marine pollutants coming from ships.wastes and fuel residues consists mainly of contaminated water. Modern ships are fitted with holding tanks, which allows overboard discharge in allowable sea areas. Specific standard discharge connections are required to enable pipes of reception facilities to be connected with ships in case discharge of sewage is performed at shore reception facilities. Chapter 3 regulation 9 of the revised Technical Annex IV of MARPOL 73/78 requires that a ship has to be equipped with any of the following equipment for prevention of marine pollution from sewage coming from ships: 1. A sewage treatment Plant 2. A sewage comminuting and disinfecting system approved by the administration 3. A holding tank
  26. 26. C. Sewage treatment plant the sewage treatment plant or comminuter or the holding tank should be in accordance with standards set by the IMO. D. Garbage Disposal System >garbage is another source of marine pollution from ships. The Technical Annex V to MARPOL 73/78 provided regulations concerning the disposal of garbage. Ships are required to be fitted with comminuter or grinder. Discharge regulations for garbage and wastes, which are either comminuted or grounded are also required.
  27. 27. SUMMARY i. There are various operations on board ships that generates marine pollution. These are bunkering, cargo loading, cargo discharging, tank cleaning, garbage disposal system, and sewage treatment and disposal operations. ii. Since bunkering operations are the main source of marine pollution from ships, extreme care are to be exercised by shipboard personnel during the performance of these activities. Particularly important is tanker operations because og the nature of cargo that are carried on board ship. iii. Precautionary measures are supposed to be ensured to avoid hazards to life and marine environment in every performance of particular activities involving the handling of oil or petroleum cargoes. iv. MARPOL 73/78 provides important regulations covering the equipment to be used and the conditions when the discharges may be permitted
  28. 28. End of Chapter 5

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