Summit Tunnel: from fire to ice

In the rush to flee the burning vehicles and fumes driver Stanley Marshall had no time to place track circuit operating clips on the track to change all signals to danger, but told the accident inquiry that he would have attempted to warn any oncoming trains by waving his lamp. As his train had not yet left the tunnel and still occupied the signalling section its rear was protected by a red light.

The initial call for assistance was received by Greater Manchester Fire Service at 0608, and was relayed to West Yorkshire Fire Service at 0613 so crews could be despatched to both portals. Three pumping appliances and one foam tender were in place at both ends by 0622, sent from Littleborough and Rochdale fire stations.  

The first responders were able to enter the tunnel for a distance of one mile from the southern end and 1,000 yards from the northern end to assess the situation. Under supervision, the traincrew were asked to return to the train at 0840 to uncouple the locomotive and three tank wagons located forward of the derailment and drive them to safety, thereby removing 16,000 tonnes of fuel from the reach of the flames. 

At this stage, the fire began to develop more rapidly as more wagons caught fire and the rising temperature of the tunnel forced open the pressure release valves of all ten remaining wagons. The vented vapour caught fire, prompting firefighters to rapidly withdraw from the tunnel. Rolling along at roof level, flames began to be vented up the three of the tunnel’s 14 ventilation shafts nearest the train, fortunately allowing firefighters to retreat unharmed. As the fire burned out of control, a major incident was declared at 1005 and the decision taken to introduce high expansion foam down four ventilation shafts to starve the fire of oxygen. There were further problems for firefighters raising water from the Rochdale Canal further down the valley as pumping equipment requiring a flat base could not be easily placed on steep hillsides and embankments. 

At the height of the blaze on December 20, the combustion process was so fuel-rich that there was inadequate oxygen inside the tunnel to feed the flames. This caused superheated vapour to explode through the ventilation shafts at over 100mph, reaching 40m into the air. In the biblical scenes above the tunnel, burning projectiles rained onto the hillside, setting fire to vegetation, prompting the evacuation of 170 local residents in Littleborough and Walsden and the closure of the Todmorden to Rochdale A6033 road. 

By 0900 on December 21 there were no more visible flames and fire crews re-entered the tunnel to begin tackling isolated fires at track level but reported loud and disconcerting noises as cooling brick, metal and rock began to contract. 

The signal was eventually sent that the situation had been brought under control at 1838 on December 24. 

British Rail inspectors were granted entry on December 27 to assess the damage, and the Fire Service presence was finally ended on January 03 1985.

Initial site inspections revealed scorched sleepers and vitrified brickwork where the tunnel lining had melted in the heat and flowed as glass-like deposits down the tunnel wall.

Both tracks were distorted, and most of the steel tank wagons had collapsed in on themselves with evidence of melting.  

The investigation concluded that the axle failure probably occurred as a result of incorrect assembly and that the wagon concerned had re-entered service only ten days before the accident with reconditioned wheelsets. 

As the petrol train had last passed a hot axlebox detector over 70 miles from the accident site to the north of York on the East Coast Main Line, the report concluded that a detector sited on the approach to Summit Tunnel might have averted the accident once an axle failure looked imminent. It therefore called for their installation at more frequent intervals and at strategic places such as long tunnels or bridges where evacuation and fire fighting could prove difficult.

The report also made clear the potential consequences had the train been carrying a nuclear load and not petrol.  

In terms of restoration, crucially the tunnel had been built with five to ten rows of bricks around the bore and as only the first three rows had been melted it retained its structural integrity and was quickly established to be repairable.

British Rail’s Preston area civil engineer Stewart Duncan oversaw the work, which could not begin until the charred wreckage of the burned out tankers could be cut into small pieces and removed on small trolleys over a three-month period. Only in March 1985 could a full civil engineering assessment finally be undertaken. 

650 yards of new double track was laid and long stretches of new concrete lining were sprayed into the spaces where damaged brick had been removed. The two ventilation shafts immediately above the crash site were steel braced, filled with foam and capped top and bottom with concrete to prevent collapse. Half a mile of telecommunications and signalling cabling was replaced. The full cost of the tunnel’s restoration was estimated to exceed £1 million.   

While repairs were completed, rail replacement buses ran between Rochdale and Todmorden while freight was diverted via the Huddersfield and Diggle route. On August 17 1985 Todmorden Rotary Club organised a walk through the tunnel from end to end before the line re-opened for traffic on August 19.

The first passenger service was the 0650 Manchester Victoria-Leeds, and a ceremonial re-opening took place later that morning when a party of local dignitaries and MPs gathered on Todmorden station to watch a Class 142 DMU break through a tape and proceed under a celebratory arch of water, aptly provided by the West Yorkshire Fire Service.