Summit tunnel fire
Encyclopedia
The Summit Tunnel fire occurred on 20 December 1984 on a dangerous goods
Dangerous goods
Dangerous goods are solids, liquids, or gases that can harm people, other living organisms, property, or the environment. They are often subject to chemical regulations. "HazMat teams" are personnel specially trained to handle dangerous goods...

 train
Train
A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...

 passing through the Summit Tunnel
Summit Tunnel
The Summit Tunnel in England is one of the oldest railway tunnels in the world: it was built between 1838 and 1841 by the Manchester and Leeds Railway beneath the Pennines...

 on the Greater Manchester
Greater Manchester
Greater Manchester is a metropolitan county in North West England, with a population of 2.6 million. It encompasses one of the largest metropolitan areas in the United Kingdom and comprises ten metropolitan boroughs: Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford, Wigan, and the...

/West Yorkshire
West Yorkshire
West Yorkshire is a metropolitan county within the Yorkshire and the Humber region of England with a population of 2.2 million. West Yorkshire came into existence as a metropolitan county in 1974 after the passage of the Local Government Act 1972....

 border, on the rail line between Littleborough and Todmorden
Todmorden
Todmorden is a market town and civil parish, located 17 miles from Manchester, within the Metropolitan Borough of Calderdale, in West Yorkshire, England. It forms part of the Upper Calder Valley and has a total population of 14,941....

, England.

History

The tunnel, which is 1.6 miles (2.6 km) in length, was built in the late 1830s. The construction shafts, at intervals of (approximately) 200 metres (218.7 yd), were left open to help vent smoke and steam from the locomotive
Locomotive
A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

s that passed through it.

The fire

The fire occurred at 5.50 a.m. on 20 December 1984 when a goods train carrying more than 1000000 l (219,969.2 imp gal; 264,172 US gal) (835 t (821.8 LT; 920.4 ST)) of four-star petrol in thirteen tankers
Tank car
A tank car is a type of railroad rolling stock designed to transport liquid and gaseous commodities.-Timeline:...

 entered the tunnel on the Yorkshire (north) side. One-third of the way through the tunnel, a defective axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...

 bearing
Bearing (mechanical)
A bearing is a device to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as well as by the directions of applied loads they can...

 (journal bearing) derailed the fourth tanker, which promptly knocked those behind it off the track. Only the locomotive
Locomotive
A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

 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
Hot box
A hot box is the term used when an axle bearing overheats on a piece of railway rolling stock. The term is derived from the journal-bearing trucks used before the mid 20th century. The axle bearings were housed in a box that used oil-soaked rags or cotton to reduce the friction of the axle...

.

The three train crewmembers could see fire spreading through the ballast
Track ballast
Track ballast forms the trackbed upon which railway sleepers or railroad ties are laid. It is packed between, below, and around the ties. It is used to facilitate drainage of water, to distribute the load from the railroad ties, and also to keep down vegetation that might interfere with the track...

 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
Telephone
The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...

 connection to the signaller) to raise the alarm.

Crews from Greater Manchester Fire Brigade
Greater Manchester Fire and Rescue Service
Greater Manchester Fire and Rescue Service is the statutory emergency fire and rescue service for the metropolitan county of Greater Manchester, England.Greater Manchester Fire and Rescue Service covers an area of approximately...

 and West Yorkshire Fire Brigade
West Yorkshire Fire and Rescue Service
The West Yorkshire Fire and Rescue Service is the county-wide, statutory emergency fire and rescue service for the metropolitan county of West Yorkshire, England...

 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.

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 (BA) in to begin their firefighting operation at the south end of the train. They also lowered hoselines down one of the ventilation shaft
Ventilation shaft
In subterranean civil engineering, ventilation shafts, also known as airshafts or vent shafts, are vertical passages used in mines and tunnels to move fresh air underground, and to remove stale air....

s 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.

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
Spall
Spall are flakes of a material that are broken off a larger solid body and can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure...

 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.

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 tankers melted (at approximately 1530 °C (2,786 °F)) 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 vent 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 approximately 45 metres (147.6 ft) high rose from the shaft outlets on the hillside above.

The gases are estimated to have flowed up these shafts at 50 metres per second (111.8 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
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

) 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 around the top of the shaft.

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
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

. By mid-afternoon 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
River Roch
The River Roch is a river in Greater Manchester in North West England, a tributary of the River Irwell that gives Rochdale its name.-Course:...

, possibly creating explosive atmospheres in the nearby towns of Summit and Todmorden
Todmorden
Todmorden is a market town and civil parish, located 17 miles from Manchester, within the Metropolitan Borough of Calderdale, in West Yorkshire, England. It forms part of the Upper Calder Valley and has a total population of 14,941....

, which were partially evacuated in response.

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 7 January 1985.

Aftermath

Of the 1100000 l (241,966.2 imp gal; 290,589.2 US gal) of petrol carried by the train, 275000 l (60,491.5 imp gal; 72,647.3 US gal) were rescued by the British Rail
British Rail
British Railways , which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages...

 (BR) train crew when they drove the locomotive and the first three tankers to safety. 16000 l (3,519.5 imp gal; 4,226.8 US gal) of petrol were recovered after the fire was extinguished and 900000 l (197,972.3 imp gal; 237,754.8 US gal) (670 t (659.4 LT; 738.5 ST)) burned. [NB these totals don't add up!]

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 (linked below) 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.

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.

The Summit Tunnel fire is worthy of note for several reasons:
  1. The size of the fire: it is probably the biggest underground fire in transportation history, certainly bigger than the 1996 Channel Tunnel fire (a relatively meagre 350 megawatts
    Watt
    The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

    ) and probably bigger than the ill-defined Salang tunnel fire
    Salang tunnel fire
    The Salang tunnel fire occurred on 3 November 1982 in Afghanistan's Salang tunnel during the Soviet occupation of Afghanistan. Details are uncertain, but the incident may have been the deadliest known road accident, and one of the deadliest fires of modern times.- Overview :The Salang tunnel,...

     in Afghanistan
    Afghanistan
    Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

    .
  2. 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).
  3. The amount of damage to the primary structure of the tunnel was minimal, although some of the bricks melted.


At a public house
Public house
A public house, informally known as a pub, is a drinking establishment fundamental to the culture of Britain, Ireland, Australia and New Zealand. There are approximately 53,500 public houses in the United Kingdom. This number has been declining every year, so that nearly half of the smaller...

 in Todmorden, The Masons Arms. there is a small collection of photographs noting the fire, along with the statistics of the construction and a quotation by George Stephenson
George Stephenson
George Stephenson was an English civil engineer and mechanical engineer who built the first public railway line in the world to use steam locomotives...

, 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".

External links

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