FLAWS IN disaster plans allowed a rail tunnel fire in the UScity of Baltimore to rage out of control for five days, bringing the city centre to a standstill.
Baltimore's Fire Department regarded the possibility of an intense fire in the 2.72km Howard Street tunnel as 'too far fetched' to include in disaster plans.
This was despite the fact that the relatively shallow tunnel passes directly beneath the city centre and is a vital link in the freight system, which completes almost 500,000 hazardous material movements each year.
Fire broke out in a 101m long tunnel after a fregith train car derailed at 3pm on Wednesday 18 July rupturing and igniting its cargo of tripropylene, used in the manufacture of plastics. The intense fire was fuelled by other freight trucks carrying an array of toxic chemicals, and paper and wood products. At times temperatures were thought to have reached more than 800C and wagons glowed in the heat.
The fire was finally extinguished early the following Monday when the last of the still-burning box-cars was pulled from the north end of the tunnel.
Although no-one was injured, the fire caused widespread chaos. Heat from the blaze ruptured a 1m diameter high pressure water main running across the top of the tunnel, depriving a large area of the city centre of its supply, and punched a large hole in the road above, flooding buildings.
Streets near the tunnel in downtown Baltimore were also closed and a local major league baseball game at a nearby Orioles Stadium had to be postponed for three consecutive days because of concern about the effects of poisonous fumes coming from the tunnel.
Telecommunications on the east coast were severely disrupted as the fire damaged cables in the tunnel.
Transport in the city was paralysed and the city's light rail system, which runs on track close to the tunnel, is expected to be out of action indefinitely.
The US government's National Transportation Safety Board (NTSB) has launched an investigation into the disaster.
Tunnel locomotives and track are all owned and operated by national freight operator CSX Corporation, although boxcars are owned by individual shipping companies.
The NTSB investigation is expected to take several months, but a key factor is the Baltimore Fire Department dismissal of the the tunnel as a particular risk.
'If someone had suggested a scenario such as this, with train derailments, chemical fires and burst water mains, we would have said no, that's too far fetched, ' said Baltimore Fire Department battalion dhief Hector Torres.
Constructed in 1895, the tunnel is a mix of double-lined brick arches and stone masonry arches.
Its depth varies along its length from a maximum of 20m to just 1m at the city centre junction of Howard and Lombard Streets.
Residual heat and toxic fumes even after the fire was extinguished prevented engineers carrying out anything other than a basic visual inspection until Monday afternoon. But after a thorough four hour inspection, CSX declared the tunnel to have suffered no structural damage.
'With the help and co-operation of the DPW we have completely inspected the tunnel from end to end and found it to be in excellent shape, ' declared CSX assistant chief engineer Rick Garro.
'While there is minor superficial damage to the brick facing and to previous repair work, there is no structural damage.
'There was nothing in the inspection that concerned me. It [the tunnel] was exactly as shown on the 100 year old plans.
It was constructed well, and brick is a very good product under these conditions, ' he said.