THE VULNERABILITY OF ROTTING MARINE STRUCTURES TO IGNITION BY DISCARDED CIGARETTES (THE 2003 SATURNA ISLAND WHARF FIRE)

摘要

This project studies the vulnerability of rotting marine structures (such as wharves and docks) to ignition by discarded cigarettes. The phenomenon of rotting wood was examined in detail, and related to the manner in which creosoted piles rot. Several informal tests demonstrated the ignition mechanism of rotting wood by an ignited cigarette. A series of tests determine the moisture content (MC) below which rotten Douglas Fir (also called Douglas tree, and Oregon pine; genus Pseudotsuga menziesii) will ignite and smoulder. Another series of tests determined the rate at which creosoted Douglas Fir piles used for docks and wharves will dry to the point at which they are ignitable by cigarettes. Historical records are consulted to determine the amount of rainfall before the fire. By comparison of the two studies, the moisture content of creosoted piles in a marine structure was estimated and a timeline towards ignitability was determined. A third set of four concurrent tests uses cigarettes to ignite rotten wood in exemplar test piles which smouldered and then transitioned into flaming combustion. The process was witnessed and photographed in detail. The results informed the likelihood of ignition by cigarette of a particular wharf structure in 2003 and other structures of similar construction. The likelihood of fires of similar origin was considered, and means to prevent them is discussed.