Toronto’s Yonge Street Subway bisects Toronto from Union Station at Front Street to 15.7 kilometres north at Bishop Avenue, just above Finch Avenue. It is at this northern terminus that the Enbridge Line 9B crosses Yonge Street. This is the 30-inch crude oil pipeline that used to carry crude oil from eastern ports to Ontario refineries. It is now proposed that the line be reversed to carry bitumen slurry to eastern seaports. Constructed over 20 years ago, Enbridge proposes that it now carry a higher volume of heated bitumen at higher pressures.
The pipeline, at this location under Yonge Street, has already endured heavy and constant vibration and compression. The concrete in the area will have developed cracks and crevices and the logical direction of leaking or spilled bitumen slurry at this point will be down into the Finch Subway station. Any spill of large volumes of hot bitumen slurry into the subway would be a disaster of major proportions. During morning or evening rush hours, the loss of life would be measured in the thousands.
In the confined space of a subway, bitumen itself can cause severe eye, skin, gastrointestinal and respiratory irritation. Also, in the confined space, poisonous hydrogen sulphide gas can accumulate. That will not matter after the first subway train applies its brakes and skids over rails coated with bitumen. This will be the ignition point of a fire that will kill everyone on the train and others trapped on subway platforms.
Without a comprehensive study of the grades in the subway construction and the flow characteristics of the now burning bitumen, it is hard to say how far the bitumen would run before pooling at a low point. The most likely pooling point is Sheppard Avenue station 2.3 kilometres south of the Finch station. It would certainly pool if it reached the York Mills Road station another 1.9 kilometres south in the bottom of Hoggs Hollow.
It is estimated that during the business day, a fire of this magnitude in the subway, will require the full evacuation of more than 50,000 office workers, office visitors, retail employees, retail customers, condominium and home owners and tourists from an area comprising more than 30 city blocks. Toronto’s Emergency Services would also have to consider evacuating possibly another 20,000 persons living and working in the Hoggs Hollow area.
A serious concern at this stage will be those who do not know the source of the heavy smoke from the bitumen fire. Any attempt to use water on a bitumen fire will have serious consequences. It requires carbon dioxide or dry chemical foam to suppress the fire. Firefighters will require full bunker gear with positive pressure, self-contained breathing apparatus with full-face mask.
Only the Toronto Transit Commission would be able to determine the requirements of repairing the subway after such a disaster but smoke damage alone to surrounding office buildings, condos, retail establishments and homes would likely tie up the courts for the next five years. We have no idea how Enbridge is prepared to handle the resultant wrongful death and injuries suits.
(NOTE: Hazards of bitumen as described are taken from the Material Safety Data Sheet on Bitumen from Syncrude Canada Ltd., Fort McMurray, Alberta.)
Copyright 2013 © Peter Lowry
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