Comprehensive reading marpol-73/78 1992 Amendments to Annex I Regulations for the Prevention of Pollution by Oil

Operational discharges of oil from tankers are allowed only when all of the following conditions are met:

1. the total quantity of oil which a tanker may discharge in any ballast voyage whilst under way must not exceed 1/15,000 of the total cargo carrying capacity of the vessel;

2. the rate at which oil may be discharged must not exceed 60 litres per mile travelled by the ship;

3. no discharge of any oil whatsoever must be made from the cargo spaces of a tanker within 50 miles of the nearest land.

Unless expressly provided otherwise, the provisions of this Annex shall apply to all ships. It should be paid to some terms that are used across the document. Tank means an enclosed space which is formed by the permanent structure of a ship and which is designed for the carriage of liquid in bulk. Wing tank is any tank adjacent to the side shell plating, while centre tank means any tank inboard of a longitudinal bulkhead. Slop tank is a tank specifically designated for the collection of tank draining, tank washings and other oily mixtures. DW or deadweight means the difference in metric tons between the displacement of a ship in water of a specific gravity of 1.025 at the load waterline corresponding to the assigned summer freeboard and the lightweight of the ship.

“Special areas" are considered to be so vulnerable to pollution by oil that oil discharges within them have been completely prohibited, with minor and well defined exceptions. The 1973 Convention identified the Mediterranean Sea, the Black Sea, and the Baltic Sea, the Red Sea and the Gulfs area as special areas. All oil carrying ships are required to be capable of operating the method of retaining oily wastes on board through the "load on top" system or for discharge to shore reception facilities. In special areas, discharge into the sea of oil or oily mixture from any oil tanker and ship over 400 grt is prohibited. Regulation 9 and 10 of Annex should not be applied in case of damage to a ship or its equipment and in some other cases.

This involves the fitting of appropriate equipment, including an oil discharge monitoring and control system, oily water separating equipment and a filtering system, slop tanks, sludge tanks, piping and pumping arrangements.

New oil tankers (i.e. those for which the building contract was placed after 31 December 1975) of 70,000 tons deadweight and above, must be fitted with segregated ballast tanks large enough to provide adequate operating draught without the need to carry ballast water in cargo oil tanks.

Originally oil tankers were permitted to discharge oil or oily mixtures at the rate of 60 litres per nautical mile, and it was reduced this to 30 litres. For non-tankers of 400 grt (gross registered tonnes) and above the permitted oil content of the effluent which may be discharged into the sea is cut from 100 parts per million to 15 parts per million.

Existing tankers of 150 gross tonnage and above, and every other ship of 400 gross tonnage and above are subject to an enhanced program of inspections during their periodical, intermediate and annual surveys. Tankers that are five years old or more must carry on board a completed file of survey reports.

On a ballast voyage the tanker takes on ballast water (departure ballast) in dirty cargo tanks. Other tanks are washed to take on clean ballast. The tank washings are pumped into a special slop tank. After a few days, the departure ballast settles and oil flows to the top. Clean water beneath is then decanted while new arrival ballast water is taken on. The upper layer of the departure ballast is transferred to the slop tanks. After further settling and decanting, the next cargo is loaded on top of the remaining oil in the slop tank, hence the term load on top. No ballast water shall be carried in any oil fuel tank, except as provided in paragraph (2) of this Regulation.

An International Oil Pollution Prevention Certificate shall be issued, after an initial or renewal survey either by the Administration or by any persons or organization duly authorized by it. In every case the Administration assumes full responsibility for the certificate.

The Administration shall ensure that it is equipped as far as practicable with installations to ensure the storage of oil residues on board and their discharge to reception facilities or into the sea in compliance with the requirements of paragraph (1) (b) of Regulation 9.The oil residues shall be retained on board or discharged to reception facilities. They shall be provided in all ports and terminals in which crude oil is loaded into oil tankers, in all ports having ship repair yards or tank cleaning facilities; in all ports in respect of oily bilge waters and other residues.

Any ship of 400 tons gross tonnage and above shall be fitted with an oily-water separating equipment or filtering system, while any ship of 10,000 grt is fitted with an oil discharge monitoring and control system. The oil discharge monitoring and control system

is fitted with a recording device to provide a continuous record of the oil content in parts per million and with alarm arrangements to indicate when this level cannot be maintained.. If this system has any failure it shall be noted in the Oil Record Book. It also shall be completed whenever loading of oil cargo, internal transfer of oil cargo during voyage, opening or closing of valves or similar devices which interconnect cargo tanks, opening or closing of means of communication between cargo piping, unloading of oil cargo, ballasting of cargo tanks, cleaning of them, discharge of ballast, etc. take place in the ship.

The Oil Record Book shall be signed without delay by the officer or officers in charge of the operations concerned and shall be countersigned by the Master of the ship, it shall be in an official language of the State whose flag the ship is entitled to fly and, for ships holding an International Oil Pollution Prevention Certificate (1973), in English or French.

Answer the following questions:

1. What does "Special area" mean?

2. What does "Dead weight" (DW) mean?

3. To what ships shall the provisions Annex 1 apply?

4. What surveys shall every oil tanker of 150 tons gross tonnage and above, and every other ship 400 tons gross tonnage be subject to?

5. When shall an international Oil Pollution Certificate (1973) be issued and by whom?

6. Who assumes full responsibility for the Certificate?

7. What shall the Administration ensure in the case of a ship of less than 400 tons gross tonnage other than an oil tanker whilst outside the special area?

8. Where shall the oil residues which cannot be discharged into the sea be retained?

9. How many special areas are defined and what are they?

10. Where shall ships while in a special area discharge sludge dirty ballast and tank washing waters?

11. From what ships shall any discharge into the sea of oil or oily mixture be prohibited while in a special area?

12. In what cases shall Regulation 9 and 10 of Annex 1 not apply to the discharge into the sea of oil or oily mixture?

13. In what ports and terminals shall reception facilities be provided?

14. What shall every new tanker of 70,000 tons deadweight and above be provided with?

15. How shall the capacity of segregated ballast tanks be determined?

16. Shall ballast water be carried in any oil fuel tank?

17. What tank may be designated as a slop tank in existing oil tankers?

18. What equipment shall any ship of 400 tons gross tonnage and above be fitted with?

19. In what Book shall any failure of the monitoring and control system be noted?

20. What arrangements shall the oil filtering system be provided with?