Proper handling of internal transfer of bunker and bulk oils


Published: 22 April 2021

Credit to: donvictorio /

This advisory focuses on prevention of any untoward incident during internal transfer of bunker or bulk oils onboard.

During bunkering operation, the bunker fuel is loaded into the fuel storage tanks fitted with heating coils and, when the fuel is ready to be used, it is transferred to the fuel settling tanks via the FO transfer pumps equipped with a suction strainer. Sometimes there is a transfer of fuel from one storage tank to another, typically in preparation for the next bunkering or for stability purposes. When the fuel or bulk oil is transferred between storage tanks the chief engineer should make the crew learn and understand the proper procedures and to take risk assessment measures against any pollution that may occur.

During transfer operation, the FO transfer pump should be operated manually, and the oil level should be monitored all the time. Transfer checklists should be completed prior to the internal transfer, and the FO or bulk oil transfer related valves, which are normally closed, must be operated, and should be double checked by the chief engineer or second engineer. A notice or valve tags shall be put up in the machinery control room and near the valves to show that the valve is open and in use. Other valves not in use during the transfer operation shall be kept closed and tagged.

Once the transfer operation is completed the FO transfer pump should be put in automatic and the normally opened valves should be opened, and the valves normally closed should be kept closed. The tags or notice in the engine control room and near the valves should be removed. The operational condition of the alarm level sensors, quick closing valves and shutdown devices should be tested and confirmed to be in order.

In case of emergency, immediately stop the transfer operation and then close all the valves. The crew should take immediate action to counteract the likelihood of oil discharge overboard.

Steps to be taken:

  • Transfer plan to be prepared by the chief engineer and agreed with all crew involved
  • The quantity to be transferred must be agreed after considering all conditions of trim/heel
  • The plan must be carefully considered if circumstances permit, transfer should be avoided during night-time
  • Avoid simultaneous transfer of different grades if possible
  • Deck scupper and save-alls must be plugged
  • Deck roving watch keeper must be well informed about the bunker transfer
  • The roving watch keeper shall maintain in the vicinity of the receiving bunker tank vent
  • High level alarms functionality must be tested and verified
  • Emergency stop procedures must be established
  • Bunker tanks vents must be kept open and unrestricted
  • Valve line-up must be carried out and checked. Valves not in use should be closed
  • Lines of communication onboard must be established and checked