Bunker planning, pre-bunkering checks and oil spill prevention
An increase has been observed in recent months in thenumber of pollution related incidents during routinebunkering operations. Bunkering, like a number ofshipboard activities, carries risk. However, managingthe risk and putting the relevant control measures inplace will ensure that any operation is carried out inthe safest possible manner. The Standard P&I Club has issued aSafety Bulletin regarding safe bunkering practices.
The root cause is more often due to poor on board practices, and permitting the operation to proceed at an excessive rate would be indicative of this. Also, it is important to remember that careful risk assessment and implementation of effective control measures can, in the event of an overflow occurring, contain the spill on board and prevent, or at least minimise, any environmental impact.
Bunker planning
It is important to understand and plan any operation and being pro-active in the management is essential. It is necessary that a bunker plan is produced, which should be detailed and carefully considered.
A good bunker plan should include:
a. An accurate summary of the different quantities and grades of fuel to be supplied b. A plan of which bunker tanks areto be filled, which must include the type and quantity assigned to each tank and the maximum filling volumes c. A schematic diagram of the bunker system and proper valve line-up the filling sequence and the required pumping rate, including initial, maximum and topping off rate d. An indication of the safety margin or ‘slack’ space to be left in each tank. For example, no tank is to be more than 90% full e. Soundings of each tank prior commencement of bunkering and the expected soundings/ullages on completion f. The method of sounding and or ullaging, which can be stipulated to avoid confusion g. Details of who is in overall charge of the operation, this is usually the chief engineer and it should also indicate who else is involved and their respective duties h. Emergency procedures and contacts i. Procedure of line draining and blowing after completion of bunkering j. If a common line is used for multiple grades then the line flushing volumes and procedures k. Testing of High level alarms setting in the fuel oil tanks or a substitute means incase alarms are not provided l. Proper identification and markings of the valves on the bunker lines m. Procedure for changing over tanks during the bunkering n. Vessel stability drafts, trim and list during the various stages of bunkering o. Manning requirements to execute the operation safely. |
It is vital to remember that bunkering systems and other associated equipment should be kept well maintained, inspected and tested at all times.
Pre-Bunkering Checks
Upon arrival of the bunker barge, it is critically important that the engineer in charge and the barge master meet to discuss the intended operation. This meeting will include:
1. The bunker procedures, checklists and relevant risk assessments are reviewed and kept updated. These should be accurately followed and completed, prior to any bunkering operation 2. Confirmation of the bunkers being supplied, including all the various grades, densities and quantities. Sounding and ullages of all fuel tanks should be checked on-board the supply barge and on-board the ship. This should be done by both parties. The Ship Oil Pollution Emergency Plan (SOPEP) equipment should be checked and confirmation should be sought that regular drills have been conducted. The oil spill equipment should always be kept in readiness prior to any bunkering operation 3. The chief engineer and engineer officer of the watch must personally satisfy themselves that the control measures detailed on the checklist are effectively in place and must not rely totally on advice from others 4. All bunker manifold blank flanges confirmed in place, all valves closed and pressure gauges in place and operational 5. Save-alls are clean, fit for purpose and drain plugs in place, prior to bunkering 6. Deck scupper plugs are well maintained fit for purpose and confirmed as securely in-place prior to bunkering 7. All bunker tank valve positions confirmed and valve operation double-checked 8. All bunker sounding pipes confirmed as closed/capped and air vents visually inspected for blockages and/or damage 9. Fuel oil overflow tank to be checked, including the sight glass and both flow and high level alarms tested 10. Fuel oil service tanks are full and fuel purification equipment is switched off 11. The bunker system should be set up in preparation for the intended bunkering operation and then double-checked 12. Effective communication (Primary and Back up) and emergency stop signals have been established between the responsible officers on the vessel and the bunkering facility 13. Fire fighting system is in readiness 14. Sampling method and point to be agreed on 15. Sighting relevant checklists as completed correctly by both parties 16. Making mooring arrangements and the continuous monitoring of such 17. A thorough visual examination of the loading hose for damage and if necessary certification witnessed. Once the hose is attached, the engineer in charge should inspect the hose to ship’s manifold connection to ensure the gasket is fitted correctly and that ALL bolts are tightly in place 18. Checking the waters around the ship and barge for any signs of existing pollution or any other hazard 19. Ensuring that the relevant fire safety notices and equipment are posted at sensitive areas and that any signals required by port or international regulations are displayed. |
Summary and Conclusion
To reduce the possibility of a spill occurring, or to minimise the effects of any spill, it is important to:
a. Always ensure sufficient people familiar with the bunkering system and operation are allocated to the ship’s team. Insufficient personnel have been the cause of numerous spills particularly when topping off tanks b. Always start the bunkeringo peration at a low pumping rate. Once the system has been checked for leaks and free-flow, the rate can be increased to the agreed pumping rate. When checking for leaks always remember to include the opposite manifold that is not being used. Check all bunker tanks to ensure that the fuel is only being received into the correct tanks c. Continuously monitor tank levels, including tanks not in-use and remember to keep to the agreed tank capacity safety margin d. Keep accurate and regular records to monitor pumping rates and check gauges to ensure that line pressures are not too high e. Make regular checks on the bunker overflow tank sight glass and tank level- continuously check primary and back up communication methods f. Make regular checks on the mooring arrangement. Keep a ‘good eye’ on passing traffic g. Make regular inspections of the manifold and hose. The operation must halt if any small drips are seen and the leak be rectified immediately h. Make regular inspections of the bunker tank sounding pipes and relevant vents. Remember to close and cap sounding pipes at all times, when not in use i. Change over tanks in a timelymanner and allow enough ullage space in tanks to verify valve positions. Remember always open the next designated tank valve first before shutting the current tank valve j. Remember to monitor tanks that are completed and to double check that valves are properly closed. Consider visually inspecting remotely operated valves to verify their open and closed positions when ‘topping off’ tanks, inform the bunkering facility and reduce the pumping rate. Remember to maintain the tank capacity safety margin at all times k. Drain off rain or other water scuppers dry and prevent the free flow of oil over board in the event of a spill l. Keep watch handovers to a minimum and, if they are necessary, they should be detailed, accurate and fully informative of the on-going operation m. Remember to manage the operation in conjunction with the barge. Do not allow the barge to dictate how the operation is managed n. Make sure that the MARPOL drip sample is functioning correctly and the relevant samples are drawn. Double check the delivered temperature and carry out compatibility tests, where required o. Stay alert throughout the full bunkering operation and investigate changes or discrepancies immediately. If in doubt do not hesitate to suspend the operation. |
Image Credit: The Standard P&I Club
Ships safety management systems identify bunkering operations as special tasks and as such detailed procedures are normally available of how they should be performed by the ship’s crew. Ensuring that these procedures are strictly adhered to is essential in minimising the risk. Add to this the sound planning, detailed communication, thorough monitoring, competent execution and safety margins/control measures all as discussed above, and the risks associated with bunkering operations can be managed accordingly. |