Box Tunnel

The Box Tunnel in Wiltshire is one of our finest Victorian structures. It’s also one of the railway’s greatest triumphs.

Once completed, it inspired short stories and poems, cementing itself in the minds of the Victorian public as a marvel of the age.

Yet there would come backlash. It was labelled as ruinously extravagant. The media publicised its virtues but also reported on the fears of the public, who were terrified about travelling through the subterranean darkness.

There was also a large human cost to its ambitious construction, with more than 100 deaths occurring during the project.

Inside, the site smelt of smoke and gunpowder. The dark and dim vault filled with clouds of vapour and only feeble candlelight saved it from utter blackness.

Original drawing of the Box Tunnel, owned by the Network Rail archive

Its designer, Isambard Kingdom Brunel, achieved the impossible at Box despite the harsh working conditions, tragic deaths and controversy.

With it, he pushed the boundaries of engineering and created one of the world’s most iconic examples of tunnel design.

Isambard Kingdom Brunel

Box Tunnel in numbers

  • One tonne of candles needed each week so the workers could see inside the tunnel
  • One tonne of explosives a week to blast through the earth
  • Less than two inches – the difference of alignment when the two ends of the tunnel from the east and west sides of Box Hill met in the middle
  • 4,000 – the number of men needed to finish its construction after the project missed its deadline
  • More than 100 – deaths during the project
  • 300ft – the depth of the deepest shafts dug inside the tunnel (about 100ft taller than York Minster)
  • More than 20 million – the bricks it took to build

Video: the Box Tunnel in Wiltshire

Click below for the extraordinary history of the Box Tunnel

1833: A young civil engineer, known for his work on the Thames Tunnel, is appointed the chief engineer of the newly formed Great Western Railway in 1833. This is 27-year-old Isambard Kingdom Brunel.

His vision was vast. He wanted to create a connection between London and New York, taking his railway from Paddington, to Bristol and then on to South Wales, where a ship could be taken to NY. His route was chosen to avoid steep gradients, except for Box Tunnel.

31 August 1835: the Great Western Railway was authorised by an Act of Parliament to build the railway line between the cities of London and Bristol.

1835-1836: Box Tunnel is the greatest challenge on the Great Western Railway – a feat thought impossible due to the area’s geology. The company states in the press that Box Tunnel “is considered to be the most difficult part of the line; but we are happy to state that it presents no obstacle that is not readily surmountable by skill and perseverance”. The completed tunnel is to be 1.8 miles long, making it the longest tunnel of any kind in the world. William Glennie, one of Brunel’s personal assistants, is in charge on site until completion.

April 1837: Keeping the water out of the workings is difficult but Brunel employs some of his workers from the Thames Tunnel to help the contractor keep the water out. Horses take away removed earth because there is no way to bring water to the top of Box Hill to feed a steam engine.

November 1837: Great distress abounds at the Great Western Railway about work between Chippenham and Box Tunnel. Several sub-contractors default on their payments and can no longer pay their workers. Residents of Corsham take pity on them and for 10 days feed and care for them. On 12 November the first recorded death takes place. John Fowles, aged 24, is crushed by falling masonry at the bottom of shaft number three.

1838: George Burge, the contractor for St Katherine Docks in London, becomes a contractor for the project.

June 1838: Work progresses slowly due to the constant influx of water from nearby springs. Some shafts have 20ft of water in them.

The media at the time described the instances of death during the Box Tunnel works as frightful. Although sources differ, most agree that there were more than 100 deaths in total over the course of the project.

September 1838: Daniel Thomas, the youngest death recorded during the works, aged 15, dies, falling 200ft to the bottom of shaft number five. It is said that by November 1838, 19 men had lost their lives.

December 1838: Work has all but ceased at Box Tunnel due to the influx of water making it almost impossible to keep working. New steam engines are built at shafts six and seven to contend with the water.

January 1839: It’s believed the Great Western Railway will open in 1840. But it is clear that Box Tunnel will not be finished in time.

November 1839: Fifty lives are lost at Box Tunnel to date.

1840: Constant news about accidental deaths in the tunnel.

January 1841: Brunel cajoles his contractors to increase their workforce from 1,200 to 4,000 men in an attempt to finish the tunnel soon.

30 June 1841: Box Tunnel opens. It’s about 3,200 yards in length and used more than 20 million bricks.

9 April 1842: Brunel’s personal assistant William Glennie reports the first instance when the sun shone directly through the tunnel and will once again in October.

According to the biography of Brunel written by his son, when the tunnel opened, people so afraid of it that they would leave the train before the tunnel. They would instead travel along the turnpike road before catching the train again at Box station.

1844: Box Tunnel is used as an example of the impossible made possible in talks about how difficult it would be to build a railway through hilly South Devon.

1845: a large stone falls from the roof of Box and onto the line in front of a train, derailing it.

Railway promotions use their projected routes between London and Bristol and their avoidance of Box Tunnel as selling points. The Direct Western Railway cites an advantage that it will connect with London and Bristol but avoid Box Tunnel, which “is the object of fear to so many travellers”.

1857: Charles Reade, the English novelist, writes The Box Tunnel, a short story for American audiences.

1939-1945: In WWII part of the quarrying tunnels at the eastern end of box tunnel were used to store ammunition for the Army. The Royal Air Force at RAF Box also used the tunnel. Part of the tunnel was also used for the Bristol Aeroplane Company and housed its experimental department.

1986: restoration of the tunnel was undertaken. A viewing platform on London Road (A4, Bath) was opened to give visitors the best view of the western portal.

2009: the electrification of London (Paddington) – Bristol – Swansea announced by Network Rail.

March 2010: Network Rail clears overgrown plants and foliage growing along the embankment around the tunnel’s west portal to improve the vista from the viewing platform on London Road.

Read more:

Our history

The Network Rail archive

Eminent engineers

Iconic infrastructure

What's a Main Line? Rail history explained

Incredible Stephenson railway history rediscovered

Read the George Stephenson notebook online

People and the railway: the Railway Heritage Trust