The Summit tunnel fire occurred on a dangerous goods train passing through the Summit Tunnel on the Yorkshire/Greater Manchester border, England on December 20, 1984. In rail transport, a train consists of a single or several connected rail vehicles that are capable of being moved together along a guideway to transport freight or passengers from one place to another along a planned route. ... The Summit tunnel in England is one of the oldest railway tunnels in the world: it was built between 1838 and 1841 beneath the Yorkshire Dales. ... Royal motto (French): Dieu et mon droit (Translated: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area – Total Ranked 1st UK 130,395 km² Population – Total (mid-2004) – Total (2001 Census) – Density Ranked 1st UK 50. ... December 20 is the 354th day of the year (355th in leap years) in the Gregorian calendar. ... 1984 (MCMLXXXIV) is a leap year starting on Sunday of the Gregorian calendar. ...

At 5.50 a.m. a goods train carrying more than a million litres (835 tonnes) of four-star petrol in 13 tankers entered the tunnel on the Yorkshire side. One-third of the way through the tunnel, a defective axle bearing derailed the fourth tanker, which promptly knocked those behind it off the track. Only the locomotive and the first three tankers remained on the rails. One of the derailed tankers fell on its side and began to leak petrol into the tunnel. Vapour from the leaking petrol was probably ignited by a hot axle box. Gasoline, as it is known in North America, or petrol, in many Commonwealth countries (sometimes also called motor spirit) is a petroleum-derived liquid mixture consisting primarily of hydrocarbons, used as fuel in internal combustion engines. ... An axle is a central shaft for a rotating wheel or gear. ... A bearing is a component used to reduce friction in a machine. ... A locomotive (from lat. ...

The three train crew could see fire spreading through the ballast beneath the other track in the tunnel, so they ran the remaining mile to the south portal (where they knew there was a direct telephone connection to the signaller) to raise the alarm. Ballast may mean : Something that improves stability Track ballast (gravel or cinders) forms the railroad or railway track-bed on which sleepers (ties) and track is laid. ... The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device which is used to transmit and receive sound (most commonly voice and speech) across distance. ...

Crews from Greater Manchester and West Yorkshire fire brigades quickly attended the scene. Co-ordination between the brigades appears to have worked well, perhaps because they had both participated in an emergency exercise in the tunnel a month before. Greater Manchester is a metropolitan county in England established in 1974 which covers an area roughly encompassing the conurbation surrounding the City of Manchester. ... West Yorkshire is a metropolitan county in England, corresponding roughly to the core of the West Riding of the traditional county of Yorkshire. ...

Figure 1: looking south along the upline track, showing petrol tankers 11 and 12.

The train crew were persuaded to return to the train, where they uncoupled the three tankers still on the rails and used the locomotive to drive them out. Greater Manchester fire brigade then loaded firefighting equipment onto track trolleys and sent a crew with breathing apparatus in to begin their firefighting operation at the south end of the train. They also lowered hoselines down one of the ventilation shafts to provide a water supply. At the same time, crews from West Yorkshire fire brigade entered the tunnel and began fighting fires in the ballast at the north end of the train, as shown in Figure 1. Summit tunnel fire, tankers relatively unscathed. ... Summit tunnel fire, tankers relatively unscathed. ... SCBA is an acronym for Self Contained Breathing Apparatus. ...

However, at 9.40 a.m. the pressure in one of the heated tankers rose high enough to open its pressure relief valves. The vented vapour caught fire and blew flames onto the tunnel wall. The wall deflected the flames both ways along the tunnel, the bricks in the tunnel wall began to spall and melt in the flames and the BA crews from both brigades decided to evacuate. They managed to leave just before the first explosion rocked the tunnel. Spall are flakes of a material that are broken off a larger solid body. ...

Left to itself, the fire burned as hot as it could. As the walls warmed up and the air temperature in the tunnel rose, all ten tankers discharged petrol vapour from their pressure relief valves. Two melted (at approximately 1530 °C) and discharged their remaining loads as floods.

The fuel supply to the fire was so rich that some of the combustibles were unable to find oxygen inside the tunnel to burn with: they were instead ejected from blast relief shafts 8 and 9 as superheated, fuel-rich gases that burst into flame the moment they encountered oxygen in the air outside the tunnel. At the height of the fire, pillars of flame rose from the shaft outlets on the hillside above (Figures 2 and 3: bear in mind that the shafts are 3 metres (10 feet) diameter and that the flames are about 45 m (145 feet) high).

Figure 2: Pillars of flame from vent shafts 8 and 9 at the height of the fire.

Figure 3: Close-up of vent shaft 8; the tree and dirt road to the right of the shaft give a sense of scale.

The gases are estimated to have flowed up these shafts at 50 m/s (110 mph). Air at this speed is capable of blowing around fairly heavy items: hot projectiles made from tunnel lining (rather like lava bombs from a volcano) were cast out over the hillside. These set much of the vegetation on fire and caused the closure of the A6033 road. In the clearup operation afterwards, small globules of metal were found on the ground surrounding shaft 9 - these had been melted from the tanker walls, swept up with the exhaust gases, and dropped out onto the grass. Summit tunnel fire: shaft 8 outlet (foreground), shaft 9 outlet (background). ... Summit tunnel fire: shaft 8 outlet (foreground), shaft 9 outlet (background). ... Summit tunnel fire: close-up of the bunsen burner at shaft 8. ... Summit tunnel fire: close-up of the bunsen burner at shaft 8. ... Look up lava, Aa, and pahoehoe in Wiktionary, the free dictionary. ... Eruption redirects here. ...

Unable to get close enough to safely fight the fire directly, the fire brigades forced foam into ventilation shafts far from the fire. This created blockages that starved the fire of oxygen. By midafternoon the next day the inferno was no longer burning, though the fire was by no means knocked down. Petrol continued to leak from the derailed wagons through the tunnel drainage and ballast and the vapour sporadically re-ignited when it came into contact with the hot tunnel lining. It also became apparent that petrol vapour had leaked into the nearby river Roch, possibly creating explosive atmospheres in the nearby towns of Summit and Todmorden, which were partially evacuated in response. General Name, Symbol, Number oxygen, O, 8 Chemical series Chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... The River Roch (pronounced roach) is a river in Greater Manchester in north-west England, a tributary of the River Irwell that gives Rochdale its name. ... Todmorden is a town in the county of West Yorkshire, England. ...

The brigades continued to fight the fire for a further two days, until West Yorkshire fire brigade issued the stop message just after 6:30 p.m. on Christmas Eve. Fire crews remained at the site until January 7, 1985. January 7 is the seventh day of the year in the Gregorian calendar. ...

Of the 1.1 million litres of petrol carried by the train, 275,000 litres were rescued by the BR train crew when they drove the locomotive and the first three tankers to safety. 16,000 litres of petrol were recovered after the fire was extinguished and 900,000 litres (670 tonnes) burned.

Figure 4: Tanker 9, crowned with glassy deposits formed by bricks in the shaft above; the bricks melted, dripped down and solidified on top of the tanker.

The damage done by the fire was minimal. Approximately half a mile of track had to be replaced, as did all the electrical services and signalling. The biggest surprise was how well the brick lining had stood up to the fire. Although some bricks in the tunnel and in the blast relief shafts had become so hot that they vitrified and ran like molten glass, most of the brickwork lining of the tunnel was scorched but still serviceable. One of the photographs taken in the aftermath shows a rail tanker directly beneath shaft 9: it is crowned with a mass of vitrified slag from bricks in the shaft that had melted and dripped down (Figure 4). Summit tunnel fire: photograph of solidified brick slag on top of tanker 9. ... Summit tunnel fire: photograph of solidified brick slag on top of tanker 9. ... Vitrification is a process of converting a material into a glass-like amorphous solid which is free of any crystalline structure, either by the quick removal or addition of heat or by mixing with an additive. ...

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 it before train services resumed. Logo of British Rail British Railways (BR), later rebranded as British Rail, ran the British railway system from the nationalisation of the Big Four British railway companies in 1948 until its privatisation in stages between 1994 and 1997. ...

The Summit tunnel fire is worthy of note for several things.

Firstly, the size of the fire: it is probably the biggest underground fire in transportation history, certainly bigger than the Channel Tunnel fire (a relatively meagre 350 megawatts) and probably bigger than the ill-defined Salang tunnel fire in Afghanistan. Chunnel in cross section The Channel Tunnel, (French: le tunnel sous la Manche; often nicknamed the Chunnel in English) is a rail tunnel beneath the English Channel at the Straits of Dover, connecting Cheriton in Kent, England and Sangatte in northern France. ... The watt (symbol: W) is the SI derived unit of power. ... The Salang tunnel fire occurred on November 3, 1982 in Afghanistans only road tunnel, during the Soviet occupation of Afghanistan. ...

Secondly, the amazing luck of those who fought it. The BR train crew who returned to the site to rescue a locomotive and three tankers left the fire site shortly before one of the other petrol tankers filled the tunnel with flames. The firefighters in BA sets who were in the tunnel when it did fill with flames were saved by the fact that blast relief shafts 8 and 9 acted as flame vents (a function their designer never envisaged).

Thirdly, the amount of damage to the primary structure of the tunnel was minimal, although some of the bricks melted.

External links

• Photographs from TV news

References

• Lindley, J. The Summit Tunnel incident, Loss Prevention Bulletin no. 134, April 1997, pp14–19
• Jones, A. The Summit tunnel fire, Incident Report no. IR/L/FR/85/26. Health & Safety Executive, 1985
• Railway accident: report on the derailment and fire that occurred on 20th December 1984 at Summit Tunnel in the London Midland Region of British Railways, Department of Transport, 1986
• Karran, G. Research report on the Summit Tunnel fire, Todmorden, West Yorkshire on 20 December 1984, West Yorkshire Fire Service, 1985
• Summit tunnel: A supplementary report on the vent shaft fire, 8 August 1985, West Yorkshire Fire Service, 1985
• Duncan, S. D. and Wilson, W., Summit tunnel—post fire remedial works, 5th international symposium (Tunnelling '88), Institution of Mining and Metallurgy, 18–21 April 1988; ISBN 1870706013
• Riley, N. and Lelland, A., A review of incidents involving hazardous materials in road and rail tunnels, Proceedings of the 2nd International Conference on Safety in Road and Rail Tunnels, 1995; ISBN 0952008327