FLAWS IN disaster plans last week allowed a rail tunnel fire in the United States city of Baltimore to rage out of control for five days, bringing the city centre to a standstill.
Baltimore's Fire Department said that the possibility of an intense fire and resulting disruption in the 2.72km Howard Street tunnel was 'too far fetched' to include in disaster plans.
This was despite the fact that the relatively shallow tunnel passes directly the under the city centre and is heavily used by freight trains often carrying highly flammable chemicals.
Fire broke out on a 101m long, 60 wagon freight train at 3.07pm last Wednesday as it was travelling through the tunnel. The blaze was not fully extinguished until early Monday morning. At times temperatures were thought to have reached more than 800infinityC in the tunnel as wagons glowed in the heat.
The fire began when one of the train cars derailed, causing a tanker carrying tripropylene, a highly flammable petroleum compound used in the manufacture of plastics, to rupture and ignite its cargo.
This led to an intense underground fire fuelled by other freight trucks carrying an array of toxic chemicals, and paper and wood products.
The fire was finally extinguished early on Monday when the last of the still-burning boxcars was pulled from the north end of the tunnel.
Although no-one was injured the fire caused widespread chaos in Baltimore and beyond.
Heat from the blaze ruptured a 1m diameter high pressure water main running across the top of the tunnel. The breach starved a large area of the city centre of water and punched a large hole in the road running above it, flooding buildings (see pages 6-7).
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 will be paralysed for up to three weeks.
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 exact cause of 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 already emerging is that the Baltimore Fire Department has never considered the tunnel a particular risk. This is in spite of the fact that it is a vital link in CSX's freight system, which completes almost 500,000 hazardous material movements each year.
'We have a very proactive training schedule, and last month we completed a drill in a similar tunnel, ' said Baltimore Fire Department battalion chief Hector Torres. 'But training is always generalised as every incident is different.
'To be honest, 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, ' he said.
Firemen struggled to control the fire. Initially they tried to tackle it from both ends of the tunnel. When this failed they pumped in water through a manhole above the tunnel.
Roads above the tunnel in central Baltimore remained closed to traffic until Tuesday morning as engineers from CSX and the Baltimore Department of Public Works (DPW) assessed the structural integrity of the tunnel.
Constructed in 1895, it is a mixture 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 left over after the fire was extinguished stopped engineers carrying out anything more than a basic visual inspection until 4pm on 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 some minor superficial damage to the brick facing and to some previous repair work, which will have to be repaired at some stage in the future, 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.
'That's engineer-speak for 'there is no danger of collapse', ' said Mayor Martin O'Malley, as he used the news to reopen all roads, barring the dowtown intersection of Lombard and Howard Streets (see box).
CSX has also moved fast to repair the rail line through the tunnel. As NCE went to press it was expected that damaged rails would be replaced in time for the first train to run through the tunnel last Tuesday morning.