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Caution to be given to Ships Bunkering operation

Fuel oil bunkering is a critical operation onboard ships that require receiving oil safely into the tanks without causing an overflow of oil. When disputes arise over quantity and quality transferred, investigations after delivery are usually inconclusive if the shipboard personnel of the receiving vessel is not correct and or fully informed and trained. Protests, legal fees, management time, loss of goodwill, stress all add on to costs with usually neither party concluding with certainty what transpired onboard. We have summarized below some basic safety proceudre that might be helpful for safe bunkering operations.

The Chief Engineer should be responsible for matters that concern the engine room, including fuel oil systems and Bunkering. Taking fuel oil (Bunkering) is a potentially high-risk operation; therefore, it should always be the Chief Engineer's responsibility. However, the Master should always be aware of all that happens on a ship. Before an operation, the information should be obtained from the supplier. The Chief Engineer needs to check all safety requirements for the refueling work following a ship specific Bunkering Check List and best endeavored to prevent marine pollution.

containerships operational matters
Oil Tanker Safety Guide
System set-up It is imperative that all engineering officers are fully aware of the fuel oil bunkering system. The chief engineer should allow only engineers familiar with the system to be actively involved in bunkering operations. The Master should be fully aware during bunker operations of the quantities to be received, bunker distribution, start time, officers-in-charge, expected time of completion, and communication with all involved.

Flexible bunker hose connected at deck manifold

Before pumping starts, the tank receiving the fuel should be identified by the officer-in-charge. Furthermore, the correct system valves opened and tagged with easily identifiable valve positions. All other system valves should be checked and tagged as being closed. The system may then be cross-checked by another competent officer to ensure it is in a state of readiness to accept fuel delivery. It is recommended that this cross-check of the system set-up is part of the bunker checklist.

When commencing the bunkers, ensure that the pumping rate is slow enough to enable the system to be checked for leaks and that the fuel is being received in the desired location. Once this has been verified, the pumping rate can be increased to the safest maximum rate, ensuring that the bunker line maximum pressure is monitored and not exceeded.

Designation of personnel to engage in FO transfer work

The Chief Engineer needs to decide and draw up the List of Personnel to Engage in FO Transfer Operation. During the Bunkering operation, the Chief Engineer, the engineer in charge, the member in charge of watching the hose connection and the sea surface should not hold other jobs (for example, maintenance work) concurrently.

Preparation of Bunker plan

The bunker plan is a piping (schematic) diagram that is accurate and representative of the bunkering system onboard. The Chief Engineer should confirm and prepare the piping diagram of the FO transfer equipment suitable to the vessels equipment according to ship specific Fuel oil Transfer Procedures. The plan should show the bunkers' distribution and be posted by the bunkering station during Bunkering and must be fully understood and signed by the officers involved in the operation. Ideally, it should show the amount of fuel onboard the ship before commencing bunkers, the amount of fuel to be bunkered, and the distribution plan for bunkers with tank soundings expected upon completion. A copy of the bunker tank sounding tables should be available to all personnel and form part of the bunker plan.

Inspection and maintenance of refueling equipment

The Chief Engineer should inspect and service the refueling equipment positively, utilizing the PMS, and carry out the inspection before entering a port following the Bunkering Checklist
  1. Deck scupper: While Bunkering, the deck scuppers shall be closed with an expandable rubber plug, and if use of an expandable rubber plug is improper, a wooden plug shall be put, which shall be cemented up with suitable putty. The opinion of the USCG from the viewpoint of prevention of marine pollution, an expandable rubber plug, screw-type plug or a mechanical closing device should be used to all scuppers on the upper deck.

  2. Procedures for pressure test of refueling line

It is critical to understand the correct signal


Before commencing bunkers, an effective and reliable means of communication is to be established and agreed between both parties. The ship is to ensure that an agreed stop command and slow down command has been established with the bunker provider. The most common means of communication during bunker operations is by VHF radio.

Communication between the bunker station and the engine room is to be tested to ensure that noise from the machinery space does not interfere or block the communication from the deck and lead to misunderstanding. There are headsets available on the market that have noise cancellation technology and are ideal for the engine room to deck communication. There should be an agreed emergency stop signal available should the primary communication fail with either party. If the emergency stop signal is initiated, then the bunkering operation should be halted immediately. Some bunkering companies will place an emergency stop button linked to the barge's transfer pump, by the ship's bunkering station. It can be used by the ship's officer in charge of Bunkering should the need arise to stop the bunker barge pumping the fuel. Ensure that this is tested. During the bunkering operation, the primary means of communication is to be regularly tested.

Preparation of checklist for open / closed condition of refueling-related valves

The Chief Engineer shall prepare a checklist which employs the vessels valve names (it is desirable to mention both the name and valve No.) to check open/closed condition of valves related to refueling work (including valves to separated the refueling line from the other lines), and shall endeavor to confirm open/closed condition of valves at the beginning of refueling and change over of tanks, and the restored condition of the refueling line after the refueling, to prevent a wrong valve operation.

Bunkering under rainy weather

When the Bunkering operation is carried out under rainy weather, the Chief Engineer shall enhance monitoring capability as required for the prevention of marine pollution, including an increase in the number of watchmen on the deck. Water puddles on the deck shall be discharged through a scupper after it has been confirmed that no oil floats on the puddles. It shall be positively confirmed that the scupper has been closed after the discharge without fail.

Bunkering at night

When the Bunkering operation is not completed in the daytime, the Chief Engineer shall secure the enough deck lighting to illuminate the following places:
  1. Hose connection areas (on the vessel and on the barge)
  2. FO Transfer areas on the barge.
  3. FO Transfer areas on the vessel.
  4. Note: Enough illumination required by the USCG is: 5.0 ft. cd for hose connection area & 1.0 ft. cd for FO transfer work area


During the bunkering operation, always there exist a risk of an oil spill. It is due to the rupture of a flexible bunker pipeline, the blow-out of a damaged gasket, the opening or closing of a wrong valve, or the accidental overflow of a bunker tank. Whatever the reason, emergency procedures should be initiated without delay. In all cases, if any abnormality is felt or reported, the Chief Engineer should stop the oil transferring immediately, investigate the possible causes, and shall not restart the oil transferring until the causes have been eradicated. Should any oil leakage is discovered or reported, the Chief Engineer shall take necessary measures for "Oil Pollution Accident."

Measuring operation of Hydrogen Sulfide (H2S)

Immediately after the commencement of the bunkering operation, the engineer in charge should measure the H2S gas concentration through the air vent of Fuel Tank under the supervision of the Chief Engineer. In case the H2S gas density is higher than 10ppm, the following measures have to be taken:
  1. The personnel in charge of bunker operation at the site should put proper PPE (a gas mask)
  2. The openings to the accommodation area near fuel tank air vent should be closed completely
  3. Keep persons away from FO Air Vent, other than the persons in charge
  4. Until completion of Bunkering, the gas concentration measuring shall be carried out at regular intervals (at least once in an hour).

Toxicity Hazards

Toxicity is the ability of a substance to interrupt the correct function of bodily organs. Toxic cargoes are harmful if they are inhaled or swallowed or absorbed into the body through the skin. Most of the chemical cargoes, as well as some crude oils and petroleum products, are toxic or contain toxic components. The Master must ensure that all ship's personnel are aware of the toxic characteristics of cargo onboard. When handling a cargo, which may be toxic, the precautions contained in MSDS and ISGOTT to be followed. In case of any accident involving dangerous, hazardous or harmful substances, the IMO Medical First Aid Guide (MFAG) and IMO Emergency Procedure for Ships Carrying Dangerous Goods (EmS) are to be followed.

Ship management Company provides various gas detection equipment, including Draeger Multigas Detector, with special tubes to monitor the level of different dangerous gases in ship's compartments. The Chief Officer is responsible for up keeping the stock and order of any additional Draeger Tubes or gas detection equipment required for the cargo to be loaded. Information regarding the cargo's health hazards can be obtained from Product Data Sheets or Material Safety Data Sheets (MSDS). The most common term in use within the industry for the determination of product toxicity is the Threshold Limit Value (TLV).

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