Photographic feature; the Whitaker machine

Many engineering geologists will be involved with tunnelling projects at some time in their careers and will discover the intrinsic interest to be found in understanding how tunnelling machinery works. Although there are many examples of historic tunnels extant, very few examples of the machines that were used to drive them have survived. For this reason we should be grateful that a fine specimen of the early Whitaker tunnelling machine has been recovered more or less intact and lovingly restored to its original condition. The Whitaker tunnelling machine was designed by Douglas Whitaker and usually constructed by Sir William Arrol and Co Ltd, Dalmarnock Ironworks, Glasgow. It was conceived during the First World War as part of a plan to overcome the stalemate on the Western Front. Special companies of sappers were formed to tunnel beneath the German lines and explode huge mines under their positions. As these tunnels were excavated by hand the War Office commissioned the design of the Whitaker machine to speed things up. The machines could be used either without a shield for tunnelling through weak rocks such as the Chalk, or fitted with a shield for tunnelling through soils. The machines varied in diameter between 7ft (2.13 m) and 12 ft (3.66 m) (West 1988). The particular example of the Whitaker machine that is the subject of this Photographic Feature is a 12 ft (3.66 m) diameter model, built in 1921 by Whitaker Bros in Leeds for the Channel Tunnel Company and used to drive ... This 250-word extract was created in the absence of an abstract.