Bunkering Operations: Precautions, Checklists, Calculations & Corrections Explained
The actual Bunkering operation is carried out with bunker checklists. In this article, emphasis is made on the checklists, safety precautions, SOPEP locker & SOPEP equipments, temperature & density correction to calculate the quantity of oil bunkered. Formula for calculation has been included.
Pre-bunkering preparations. The most important aspect of bunkering operation is the "checklists", which forms a part of company's safety management system (SMS) and I.S.M.,eliminating the possibility and negligence of human and other operational errors. The pre-bunkering checklist must be followed in-consultation with the Chief Engineer (C/E), as he is the person-in-charge for the bunkering operation. Before bunkering, ususally it is 4th engineering officer, taking "soundings" of bunker tanks and calculates the volume of fuel oil available in every fuel oil tank of the ship. Then a Bunker-plan is made to plan the distribution of total quantity of bunker fuel oil. The ship Managers (superintendents) monitor the performance of a fleet of ships. For eg. On owning a car, we tend to keep a check on its fuel consumption widely called as "mileage". It is the distance travelled by the vehicle for a unit volume of fuel used. In the same way, as the ship consumes humungous quantity of fuel, whose costs are forming the major part of ship's operation, The Managers tend to keep a check on it. This is measured in terms of specific fuel oil consumption of the main propulsion engine. On knowing the fuel oil consumption for a day & next voyage plan, the quantity of fuel oil required is calculated and compared with the available bunker tank capacity. A requisition is placed through the C/E & Master of the vessel to the Managers. The requisition is processed and evaluated for the quality & quantity of fuel to be supplied for the particular ship. Planning is done for the delivery of bunker at a particular port where the oil is available at a comparitive lesser cost. On taking all these aspects into consideration, the Managers, deliver bunker to the vessel. Upon receiving the bunker, a sample collected during bunkering operation is sent for lab analysis to confirm the delivered oil meets the required standard for the safe & efficient operation of the auxiliary engines & main propulsion engine. 1. State of adjacent waters noticed 2. Vessel properly secured to dock 3. Check suppliers product corresponds to ordered product 4. Agree quantity to be supplied 6. Day tanks full and supply valves closed 7. Warning signs in position e.g. No Smoking 9. Clean up material in place 11. Foam fire extinguisher placed at bunker station 12. Alfa Laval and transfer pumps off 13. Fuel tank supply valves open 14. Agree stop/start signals between vessel and barge/truck 15. Bravo flag flying/red light showing 16. Agree pumping/transfer rate 17. Agree emergency shut down procedure 18. Specification sheet received 19. Check hose and couplings are secure and in good order 20. Fuel nozzle and hose secured to vessel 21. Check barge/truck meters Reading: 22. Check on board meters Reading: 24. Unused manifold connections blanked off 26. Signal pumping to commence The above checklist has to be completely filled religiously by both the ship & barge personnels. Please move on to the next page by clicking below Automated Bunker Procurement Flowchart: Calsoft Enterprise Solutions, USA At the bunker manifold and wherever necessary, as per the ships SOPEP plan, the SOPEP equipments should be kept in immediate readiness in order to avoid oil spill/pollution during bunkering operation. SOPEP- Shipboard Oil Pollution Emergency Plan. The SOPEP Locker must have minimum of the below specified items: 9. empty receptacles (200 ltrs capacity) 10. portable air driven pumps 12. oil spill dispersants. These items must be stowed in an easily accessible locker, clearly marked, and is to be brought on deck ready for immediate use, prior to all oil transfer operations. During Bunkering Procedures: During Bunkering checklist: 1. Witness taking and sealing of 2 representative product samples 2. Monitor fuel connections for leaks fuel flow and control tank levels 3. Change over of tanks whenever necessary. 4. Checking the rate at which bunkers are received. 5. Checking the tightness/slackness of mooring ropes. 6. Checking trim/list of the bunker barge & the ship. 7. Continuous monitoring/look outs for the vessel's position(when at anchor). During bunkering, the above checklist must be filled up and continuous monitoring of the above secified items are required till the bunkering operation is complete. After Bunkering Procedures: On completion of the bunkering operations, with the ship-barge co-ordination, the line should be blown with air to make sure the line is not filled with oil. The after-bunker checklist is followed. 2. Disconnect hose (drain before disconnecting) 3. Check barge/truck meter Reading: 4. Check ships meter Reading: 5. Sign Bunker Delivery Receipt BDR No. Bunker Delivery Report/Note). 6. Retain BDR with product sample 7. SOPEP plan returned to bridge 8. Clean up gear stowed / Oil boom returned 9. Bravo Flag/Red light stowed/switched off 10. Remove and pack away warning/safety signs 11. Foam fire extinguisher placed back in correct location 12. Complete Oil Record Book 13. Master informed of completion 14. Confirm in Oil Record Book Bunkering checklist completed Quantity Calculation & Temperature-Density Correction: After bunkering of various fuel oil tanks, the quantity in each bunkered tank must be calculated to cross-check whether the received quantity of oil matches the requisition. For calculating the quantity, "sounding" of the tanks which are "bunkered" must be taken. The "Density" of the fuel oil supplied vary from place to place. It also varies with the temperature. As a thumb rule, the density of fuel oil decreases with increase in temperature. So, when the oil is supplied at a higher temperature, then the volume of oil supplied is less than what is supplied at lesser temperature. Oil Temperature ----------------------------Density ------------------------------- Volume Of Oil Supplied Increases--------------------------------------Decreases------------------------------------Lesser Decreases--------------------------------- ---Increases -------------------------------------More Also the formula which is generally used for temperature-density correction is as follows: MT= {(t1-15)*0.00065}*volume of oil in m^3. where MT stands for metric tonnes. t1 stands for temperature of oil in bunker tanks in degree celcius, 0.00065 is the correction factor, volume of oil in m^3, is obtained from the sounding table. General Safeties During Bunkering: Emergency shut-down arrangements, Bunker line over-flow arrangements to overflow tank with audible & visual alarm, Relief valve in the bunker line, Consistent & Continuous look outs. Thus bunkering operation is direclty related to "MARPOL" annexes, i.e annex 1 and annex 6. When oil is spilled it causes marine pollution under annex 1. When the bunkered oil doesn't meet certain specifications, it causes pollution of air which comes under annex 6. | 
发表于 2010-2-22 21:52
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