Accession Number : ADA302719

Title :   Fire and Explosion Hazards of Grade E Cargo.

Descriptive Note : Interim rept. Jul 93-Aug 94,

Corporate Author : WORCESTER POLYTECHNIC INST MA

Personal Author(s) : Zalosh, Robert G. ; Finnegan, David M.

PDF Url : ADA302719

Report Date : OCT 1995

Pagination or Media Count : 64

Abstract : This study was motivated by a cargo tank explosion incident involving No. 6 fuel oil at a temperature well below its flash point. The overall objective of the study has been to evaluate the general fire and explosion hazards of high flash point liquid cargo, i.e., Grade E cargo. A review of Coast Guard and National Transportation Safety Board incident reports identified several other explosion incidents involving high flash point liquids at temperatures below their flash points. Three other incidents involved residual oil, two involved oily waste water, and one involved asphalt. The flammable atmosphere in the cargo tank in these incidents (and in other reported cases where there was no explosion) is due in some cases to cargo contamination by more volatile liquids, and in other cases to vapor evolution from the Grade E cargo itself, particularly when it is heated and/or transferred to other tanks. Laboratory tests have been conducted to determine the effect of small concentrations of contaminants on the closed cup flash point of representative Grade E cargo. Results show the addition of only 0.7% heptane by liquid volume to a sample of No. 6 fuel oil reduces its flash point from 95 deg C to 72 deg C, which is a typical temperature during No. 6 fuel oil transfer operations. Data for other Grade E cargo show similar qualitative effects, with the magnitude depending on both the cargo and contaminant flash points. These results, as well as a review of previous studies and current practices in the shipboard use of combustible gas detectors, are combined to provide an overall assessment of Grade E cargo hazards and possible protection measures.

Descriptors :   *EXPLOSION EFFECTS, *CONTAINMENT(GENERAL), *PETROLEUM PRODUCTS, *FLAMMABILITY, *CARGO SHIPS, *OIL PRODUCTS, *FIRE HAZARDS, *OIL TANKS, DATA BASES, REQUIREMENTS, ASPHALT, ALKANES, HYDROCARBONS, VOLATILITY, FLASH POINT, STORAGE TANKS, VAPOR PRESSURE, REGULATIONS, FUEL CONTAMINATION, CONCENTRATION(CHEMISTRY), BOAT AND SHIP SAFETY, GAS DETECTORS, COAST GUARD OPERATIONS, FUEL OIL, VACUUM DISTILLATION, BOAT AND SHIP ACCIDENTS, COAL TAR, LUBRICATING OILS, TANKER SHIPS, MARINE SAFETY EQUIPMENT, VEGETABLE OILS, FISH OILS, CYCLOALKANES, LIQUID EXPLOSIVES, HEPTANES.

Subject Categories : Energy Storage
      Lubricants and Hydraulic Fluids
      Marine Engineering
      Safety Engineering
      Explosions
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE