Box Tunnel
From Wikipedia, the free encyclopedia
Box Tunnel is a railway tunnel in western England, between Bath and Chippenham, dug through the Box Hill. It was built for the original route of the Great Western Railway under the direction of the GWR's engineer Isambard Kingdom Brunel.
The tunnel is 2,939m (1 mile 1452 yards) in length, straight, and descends a 1 in 100 gradient from the east. Construction started in 1836, and the tunnel opened in 1841. The lives of about 10 navvies (railway construction workers) were lost during construction. At the time of opening it was the longest railway tunnel in the world, though the Standedge and several other canal tunnels were longer. The dramatic western portal, near Box, is designed in the classical style, but the eastern portal, at Corsham, has a plain brick face. When the two ends of the tunnel were joined underground there was found to be less than 5cm (2in) error in their alignment.
Contents |
[edit] Brunel's Birthday
There is a story which states that Brunel deliberately aligned the tunnel such that the rising sun is visible through it on April 9 each year, his birthday. Opinions vary widely as to whether this is true. R. Angus Buchanan writes in Brunel: The Life and Times of Isambard Kingdom Brunel ISBN 1-85285-331-X (p.269, n.48):
- The alignment of the Box Tunnel has been the subject of serious discussion in the New Civil Engineer and elsewhere. I am grateful to my friend James Richard for making calculations which convinced me that the alignment on 9 April would permit the sun to be visible through the tunnel soon after dawn on a fine day.
On the other hand, it has been asserted [1] that it is impossible to guarantee the effect on a particular calendar day, because the angle at which the sun rises on a given date varies slightly with the cycle of leap years. This is true, but the sun subtends an angle of about half a degree, which is more than the year to year variation, and more than the field of view through the tunnel, so it quite possibly seems to fill the tunnel every year.
It is also asserted [2] that Brunel failed to account for atmospheric refraction and the effect is visible a few days too early.
Buchanan concludes (ibid., p.226):
- ...I have found no documentary evidence for the often-repeated story that Brunel aligned the Box Tunnel so that the rising sun shone through it on his birthday, even though careful examination shows that it could indeed do so, and it is certainly a good story.
It is tempting to think that with a suitable vantage point, the effect (if not Brunel's intentions) can easily be checked on 9 April. However, the appropriate point is in the middle of a high-speed railway line and is thus potentially very dangerous. Photographs of the effect have reportedly been taken with appropriate assistance from railway officials.
[edit] Cold War
Fifty feet above Box Tunnel, and around 100 feet below the surface of Box hill, lies the Cold War nuclear bunker to be used in Operation TURNSTILE, the secret redoubt for the core of the UK government, in event of a nuclear attack knocking out London. Beginning as an extensive stone mine, the site was taken over by the government for use as an ammunition dump, a factory for making Bristol aero engines, and an RAF operations centre (with an underground station). After World War II, the three underground complexes were amalgamated. The Cold War bunker known to those who knew of the TURNSTILE plan as The Quarry, or Corsham. The military called it QOC (for Quarry Operations Centre), and the site is currently occupied by the MoD's Joint Support Unit.
The tunnelling at Box revealed the existence of large amounts of good quality Bath Stone in the hillside, and Tunnel Quarry was opened in 1844 to take advantage of this, with its entrance alongside the eastern portal of Box Tunnel, and a branch line running into it. Tunnel Quarry is now closed and its entrance hidden by overgrowth, and blocked off by large steel doors. There is no reason to believe that there is a connection actually within Box Tunnel. Again, this rumour has done the rounds for years, but seems to have originated from a poor description of the actual entrance, which is just alongside the main Box Tunnel portal, and could be seen easily from passing trains. A length of poor rail inside the tunnel due to wet conditions does seem to give the impression that the train is passing through pointwork (especially when travelling at linespeed of 125mph - Box is a very 'loud' tunnel!) but there is definitely no junction inside.
However the MOD have recently put the site up for sale and the description of the bunker specifically mentions two railway platforms (each about 800 feet long), but does not mention how the associated railway lines connect to the London-Bristol railway [1].
In Summer 2003, Network Rail cleared vegetation and erected new fencing around the edge of the cutting, and across the top of the tunnel. This would appear to be for safety reasons, but it totally prevents a view of the portal, or the quarry tunnel entrance.
[edit] References
[edit] Further reading
- McCamley, Nick (2000) Secret Underground City, Pen & Sword Books Ltd, ISBN 0-85052-733-3
- Hennessy, Peter (2002) The Secret State - Whitehall and the Cold War Penguin Books, ISBN 0-14-100835-0
[edit] External links
- Map sources for Box Tunnel
- TOMPAINE list posting asserting that the "birthday" effect is impossible
- Subterranea Britannica entry on the Corsham bunkers
- "An Anorak's Paradise or a Passage To Narnia?" - mostly about the "secret junction" theory, but scroll down for the argument that the "birthday" effect arrives too early.
- Wiltshire's Secret Underground City: Burlington Articles, interactive map and video tour from BBC Wiltshire
