Twelve of the fourteen construction shafts were left open to help vent smoke and steam from the locomotives that passed through it.

[2] One day earlier on 3 December a train guard had been killed after a collision between a diesel multiple unit and parcels vans at Longsight also in Manchester.

[3] This third serious railway accident in the North West of England in less than three weeks led the Littleborough and Saddleworth MP Geoffrey Dickens to call for an inquiry into railway safety, in particular with respect to the conveyance of dangerous chemicals such as those involved in the accidents at Eccles and Summit Tunnel.

[1] At 05:50 on 20 December 1984, the train, carrying more than 1,000,000 litres (260,000 US gal) or 835 tonnes (920 short tons) of four-star petrol in thirteen tankers, entered the tunnel on the Yorkshire (north) side traveling at 40 miles per hour (64 km/h).

[1] The three train crew members could see fire spreading through the ballast beneath the other track in the tunnel, so they left the train and ran the remaining mile to the south portal (where they knew there was a direct telephone connection to the signalman) to raise the alarm.

The firefighters were saved because blast relief shafts 8 and 9 acted as flame vents (a function their designer never envisaged).

As the walls warmed up and the air temperature in the tunnel rose, all 10 tankers discharged petrol vapour from their pressure relief valves.

At the height of the fire, pillars of flame approximately 150 metres (490 ft) high rose from the shaft outlets on the hillside above.

Air at this speed is capable of blowing around heavy items: hot projectiles made from tunnel lining (rather like lava bombs from a volcano) were cast out over the hillside.

[1] Once British Rail had replaced the track and electrical services, shored up the bases of vent shafts 8 and 9 and filled the two shafts with inert foam (all this took eight months), locals were allowed a once-in-a-lifetime opportunity to walk through the tunnel before train services resumed on 19 August 1985.

[1] At the Masons Arms public house in Todmorden, there is a small collection of photographs noting the fire, along with the statistics of the construction,[citation needed] and a quotation by George Stephenson, the tunnel's builder, who said, "I stake my reputation and my head that the tunnel will never fail so as to injure any human life".