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Procedure for Bunkering Operation on a Ship
The term “bunkering” refers to the taking on board of fuel oil or transferring of fuel oil from vessel to vessel. To ensure that the procedure is correctly and safely carried out there are certain measures that need to be followed as fuel oil is a flammable liquid and can be highly explosive under the correct conditions in vapour form. There are certain steps that should be followed before proceeding to a bunker.
Bunkers are generally stored in the double bottom tanks located under the engine room. This is the area between the ship’s bottom and the tank tops and is divided into a number of separate tanks. Each tank normally has two manholes to allow access to the tanks for inspections when the tank is empty for the purpose of gas freeing or for cleaning or maintenance to the strengthening members that support the tank.Each tank will also be fitted with a vent that is open to the main deck and has a gooseneck at the end. The vent is fitted to prevent any vacuum been formed while pumping fuel from the tank and allow for the escape of explosive gases when bunkering or when the tank is empty for extended periods. The end of the vent will have a wire screen or gauze fitted to allow for the dispersing of any flame and may also contain a lightweight ball that would seal the top of the pipe and prevent any ingress of water through the pipe in the event of the pipe becoming submerged.
Each tank will be fitted with at least one sounding pipe. The sounding pipe should be watertight capable of sealing properly. A sounding refers to the full depth of the tank from top to bottom and the quantity of fuel can be determined from this sounding. An ullage may also be taken. An ullage refers to the space that remains between the top of the tank and the top of the fuel after the tank has been bunkered.
These readings are then compared to a set of tables that is supplied with the vessel after construction by the shipbuilder and is used to find the amount of fuel inside any individual tank. The tables include information on the condition of the vessel at any given time like trim and heel and when using the tables, the correct page must be found for the tank before the amount of fuel can be confirmed.
BUNKERING PROCEDURES
There are various bunkering precautions to be followed that minimize the possibility of an incident both prior to bunkering, during bunkering and after bunkering. These procedures should be legibly printed in a language that is understood by all crew and permanently posted at the bunker station or in a place where the procedures can be easily seen. The procedure should contain:
• A diagram of the vessel’s oil transfer piping, including the location of each valve, pump, control device, overflow and the shut-off valve or other isolation devices that separate the bilge ballast system from the oil transfer system as well as pump emergency stops.
• The number of persons to be on duty during oil transfer operations
• Names and ranks of certificated responsible officers in charge of oil transfers
• Procedures for tending moorings during transfer operations
• Procedures for topping off tanks and draining of hoses
• Procedures in the event of an emergency shutdown
• Procedures in the event of a spill
• Procedure for ensuring all valves are closed on completion of operation
• Sequence for closing of valves on completion of operation
The bunkering checklist should also be available and must be completed before each operation of fuel transfer from vessel to vessel, a vessel to shore or shore to the vessel.
The following procedures could be used as a guide for the bunkering procedure but each vessel would adapt the procedure to suit the specific Company regulations and Standard Operating Procedures (SOP) applicable to the specific vessel. The bunkering checklist must be signed by the Officer responsible for the procedure, both Navigation and Engineering.
The procedures to be followed for bunkering are as follows:
Initial Preparation
• Ensure all personnel are aware of the intention to bunker
• Discuss the bunkering plan and sequence will all parties involved
• Close and secure all associated overboard discharge valves
• Close and blank off all unnecessary manifold valves/connections
• Plug all deck scuppers and make them oil/watertight
• Empty and plug all save-alls
• Place oil spill materials at key locations and ensure locker is open
• Provide a means for draining off any accumulations of water on deck
• Ensure emergency stops and high-level alarms are tested and work
• Ensure communication links from bunkering station and engine room are operational
• Ensure all bunker tanks pipes are clear and all sounding pipes have caps
• Confirm there is sufficient space remaining in bunker tanks to be filled
• Ensure the necessary fire precautions have been observed
• Fire hose has been coupled and primed
• Portable extinguishers are placed at key locations
• Ensure hose is of sufficient length and in good condition
• Inspect couplings and all fittings for damage (including gaskets and seals)
• Check that hose weight does not exceed the SWL of the lifting gear
• Ensure drip trays are located under hose couplings and flanges
Pre Bunkering
• Ensure delivery note quantity and specification are correct
• Discuss plan with supplier
• Discuss emergency response procedure with supplier
• Establish a communication link between vessel and supplier
• Agree on a signalling method with supplier and ensure all communications are understood w.r.t
• Commence pumping
• Reduce pump rate
• Cease pumping and Emergency Stop
• Establish and Agree with supplier the amount of fuel oil be bunkered
• Establish and Agree on the unit of measurement (tonnes, cubic metres, barrels, etc)
• Establish and Agree on the maximum pumping rate and pressure
• Take a sample of fuel oil before pumping
• Check, agree and record meter readings
• Appoint person to tend mooring lines during bunkering
• Rig firewires (fore and aft) if necessary and applicable
• Ensure a designated overflow tank has been identified
• Prepare filling line by sequentially opening relevant valves
During Bunkering
• Ensure the bunker flag is hoisted or indicating the light is on at night.
• Commence at the minimum pumping rate
• Take a sample soon after pumping commences, witness, date, jointly countersign and retain bunker samples
• Monitor supply line pressure continuously
• Examine hose connections for leakage and ship’s side for spillage
• Reduce pumping rate and/or open next tank before topping up
• Ensure sufficient ullage in final tank remains for draining of hose and line blowing
• Close valves as each tank are completed
• Notify supplier timeously when final tank is reached
On completion
• Ensure hoses are totally drained, valves are shut and end caps are fitted
• Confirm all meter readings and soundings/ullages are correct
• Close and blank off manifold connection and disconnected hose couplings and confirm all valves are shut
• Confirm and agree with supplier about readings and record all receipt details
• Complete entry in Oil Record Book
The main sources of spillage may occur due to pipe leakage, tank overflow and tank or hull leakage
The primary concern in the event of any of this occurring would be containment. In the case of pipe leakage or overflow, it is necessary to prevent oil from spilling over the side. The first stage of prevention is by way of containers below connections and save-alls at vents. Secondary protection is provided by gutter coamings and ensuring all overboard scuppers are properly sealed.
In the event of spillage occurring anyway, ALL OPERATIONS SHOULD BE HALTED IMMEDIATELY by the quickest means possible and should not be restarted until the source of the spill has been identified and corrected.
Pipe Leakage
If the spill is identified as a pipe on the system:
• Stop the operation and close relevant valves to isolate the leaking section
• Drain the leaking section to an appropriate tank
• Carry out necessary repairs or isolate the section from the system
• Report the spill and await permission from the relevant authority to resume the transfer
Tank Overflow
In the event of a tank overflow:
• Stop the operation and close all tank valves except the relief valve for the affected tank
• The dedicated overflow tank should be opened until gravity has stopped the overflow
• Reduce the level of the oil in the tank to the intended maximum
• Investigate and correct any deficiency in the system
• Ensure other tanks are checked to prevent further overflows when operations are restarted.
• Prepare pumps to transfer ashore or back to the supplier if necessary
Suspected tank or Hull Leakage
If spillage is from a suspected hull leakage or ruptured tank:
• Close all tank valves
• Examine the ship’s side for visible leakage
• Check, record and monitor all tanks to identify which is leaking
• If the leak cannot be detected, reduce the levels of tanks in the vicinity of the leak by transferring to an appropriate tank.
If the source is identified as a leaking hull then the following action should be taken:
• Lower the level of the oil in the relevant tank until it is below sea level and the overflow has been stopped by internal transfer or by discharge ashore
• Determine from the leakage rate whether the defect is minor or major
• In the event of a minor leak the tank may be emptied out, gas freed and inspected to establish the damage for the purpose of carrying out repairs
• In the event of a major defect been identified as in the bottom or lower shell plating been damaged, the tank should be filled with water bearing in mind the stability of the vessel and the stresses that may occur in the hull. Bunkering should not restart until the Company, Owner or Charterer, and the relevant authorities have been notified and consulted.
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