MEO FUNCTION VI Miscelleneous

How to prepare a DB fuel oil tank for a survey/inspection?

Double bottom (DB) tank survey preparation:

 DB tank survey is necessary to ascertain the condition of double bottom. Before opening DB tank manhole for survey, following procedure must be followed:

  • Carry out risk assessment.
  • Arrange all tools
  • Sounding of DB tank and the tank in which remaining fuel oil is to be transferred must be taken.
  • Make sure that there is same fuel in the other tank in which oil from tank to be inspected is to be transferred.
  • If it is not possible then make sure that both oil are compatible.
  • Empty the oil, strip with portable pumps if required
  • Clean the tank with sea water and pump it out through the oily water separator
  • Ventilate the tank(s) with a blower specially provided for the purpose, always cross ventilate i.e. there should be at least two openings, each for entry and exit for the air
  • Check the space for explosive gases at various points suitably, more sampling should be carried out at the corners at the bottom most part of the tank


  FIG.: Dragger

  • Complete the enclosed space entry checklist before entry
  • Before beginning any survey the survey team should ensure that a safety meeting is held to discuss all aspects of safety referred to herein with special attention being paid to gas testing procedures, command and communication links, and rescue arrangements.

About the author

Anand Gautam

Anand Gautam is a marine engineer, Graduated from M.E.R.I. Mumbai. He likes to sail onboard ship and is one who is passionate about his job. He loves to share his knowledge, information, and ideas to everyone in a simplified way just for his satisfaction.

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