FIRE SAFETY ABOARD LNG VESSELS
摘要
This reports results of an analytical examination of cargo spill and fire hazard potential associated with the marine handling of liquefied natural gas (LNG) cargo. Principal emphasis was on cargo transfer operations at receiving terminals, and more specifically, on the LNG tanker's cargo handling and hazard sensing and control equipment and operations. Analytical procedures included historical (statistical) analysis of failure incidents for land-based and marine LNG operations and for operations with analogous cargoes, formal fault tree analysis of a 'composite' LNG tanker cargo and hazard control systems, calculation of magnitudes of potential hazards, estimation of on-site (shipboard and immediate environs) risk of fire fatality for a range of spill sizes, and calculation of fire control capabilities provided by (1) regulation, (2) current shipfitting practice, and (3) a most effective, practical system. Despite present high quality standards of design, construction, and materials for LNG tanker cargo handling equipment, hazard control systems are necessary. With hazard control systems based on design spill sizes, risk of onsite fire fatality can be reduced to at least 10 to the -10th power fatalities per person-hour exposure in the hazardous zone. Risk from cargo spills caused by an LNG tanker being rammed while docked at the terminal may also be excessive. Published U.S. regulations and codes and foreign codes and rules do not now specify protection and prevention systems which would provide the estimated reduction in risk needed to achieve the suggested tolerable level (10 to the -10th power fire fatalities per hour exposure).