Box tunnel - the Great Western Railway Tunnel

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In 1841 the Great Western Railway's London-Bristol route had only one more section to be completed. Although work on this section had begun in 1836, the work was slower because of the need to deal with Box Hill, a large limestone hill directly in the railway's path.

Isambard Kingdom Brunel rose to the challenge with a plan for the longest railway tunnel yet built. Planned to be two miles long, and running at a gradiant of 1 in 100, the Box Tunnel was greeted with scepticism when the idea was announced.

Initially two shafts were sunk, and in 1837 engineers were hired to begin building. Dealing with clay and limestone, the tunnel had to be bricklined due to the unstable nature of the rocks. A steam pumping engine kept water out of the tunnels while the men worked, but the tunnel still flooded in autumn in 1837 and 1838 (despite the improved engine Brunel added after the 1837 flood).

The sections had been cut from opposite ends and were planned to meet in the middle. When the two tunnels did, and it was found that they were exactly true and met up with less than two inches variance, Brunel was delighted. There is a story that he pulled a ring of his finger and gave it to the foreman - whether true or not, the ring is apparently still the treasured posession of the foreman's family.

Despite these successes the work fell behind. In 1840, Brunel stepped up efforts on the tunnel. With most of the GWR completed it was now one of the major issues.

In June 1841 the tunnel opened, finally establishing the London-Bristol Railway link. On the 30th June, a train made the journey between the two, from one end of the route to the other, in four hours.

Not everything went as Brunel had planned. He had wanted to leave the front of the Box Tunnel cut from limestone in the style of a gothic arch. In the event, the protests from the public who feared it would collapse forced him to add a brick frontage to the section. Potential frost damage to the limestone also affected the decision.

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Brunel also rejected a suggestion that the tunnel should be lit, making it a gloomy journey for the passengers until modern times.

Nowadays the Box tunnel is still a vital part of the London - Bristol Railway route. While the ornate front of the Box tunnel is often shown in pictures, the rear is (and remains) a simple brick archway.