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Ship to Ship (STS) Operations

Ship to Ship (STS) operations plan:



Preparation of Ships – Preparation before manoeuvres begin:

1. Ensure that the crew is fully briefed on procedures and hazards, with particular reference to mooring and unmooring.

2. Ensure that the oil tanker conforms to relevant guidelines, is upright and at a suitable trim.

3. Confirm that all essential cargo and safety equipment has been tested.

4. Confirm that mooring equipment is prepared in accordance with the mooring plan.

5. Fenders and transfer hoses are correctly positioned, connected and secured.

6. Cargo manifolds and hose handling equipment are prepared.

7. Obtain a weather forecast for the STS transfer area for the anticipated period of the operation.

8. Agree the actions to be taken if the emergency signal on the oil tanker’s whistle is sounded.

The following information should be exchanged between the two ships – Information to be exchanged between ships:

1. Mooring Arrangements.

2. Quantities and characteristics of the cargo (es) to be loaded (discharged) and identification of any toxic components.

3. Sequence of loading (discharging) of tanks.

4. Details of cargo transfer system, number of pumps and maximum permissible pressure.

5. Rate of oil transfer during operations (initial, maximum and topping-up).

6. The time required by the discharging oil tanker for starting, stopping and changing rate of delivery during topping-off of tanks.

7. Normal stopping and emergency shutdown procedures.

8. Maximum draught and freeboard anticipated during operations.

9. Disposition and quantity of ballast and slops and disposal if applicable.

10. Details of proposed method of venting or inerting cargo tanks.

11. Details of crude oil washing, if applicable.

12. Emergency and oil spill containment procedures.

13. Sequence of actions in case of spillage of oil.

14. Identified critical stages of the operation.

15. Watch or shift arrangements.

16. Environmental and operational limits that would trigger suspension of the transfer operation and disconnection and unmooring of the tankers.

17. Local or government rules that apply to the transfer.

18. Co-ordination of plans for cargo hose connection, monitoring, draining and disconnection.

19. Unmooring plan.

  • Navigational Signals

The lights and shapes to be shown, and the sound signals made are those required by the

International Regulations for Preventing Collisions at Sea (COLREGS) [8], and local

regulations. These lights and shapes should be checked and rigged ready for display prior to

the STS operation.

Dangers associated with STS operation:-

  1. Collision risk in the vicinity
  2. Cargo vapour pressure
  3. H2S content

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