MARINE GAS HAZARDS CONTROL. CLEANING AND GAS-FREEING SHIPBOARD TANKS

After listing accidents that have happened to a number of tankers following cargo-tank explosions and fires, the Author discusses the cleaning procedures followed aboard U.S. vessels at sea and in port, the testing procedures used in U.S. ports, and the certification of vessels prior to repairs. The duration of the washing period varies with the condition of the tank, the nature of the oil last carried, and the nature of the next scheduled cargo. A minimum time of half an hour is usually sufficient for washing a coated tank that previously contained a non-viscous product, but a maximum of four hours may be required for washing a scaly uncoated compartment with heavy viscous residue. After being washed the tanks must be ventilated to permit entry by personnel for final cleaning and inspection. The procedure for LNG vessels is described involving three steps: warm-up, inerting, and air filling, i.e. after inerting the tanks are air filled by using the inert-gas plant to compress and dehydrate fresh air to about -30 degrees F. This air is then used to displace the inert gas until the oxygen content of the gas exhausting from the tanks is 20%. Prior to any structural repairs involving heat in way of fuel tanks, an inspection by the U.S. Coast Guard must be carried out in accordance with NFPA Standard No. 306.

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  • Corporate Authors:

    Academic Press Incorporated

    111 Fifth Avenue
    New York, NY  USA  10003
  • Authors:
    • Savage, K M
  • Publication Date: 1976-4

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00158015
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Aug 31 1977 12:00AM