Cooke and Wheatstone Telegraph - History

History

In January 1837 Cooke proposed a design for a 60-code telegraph to the directors of the Liverpool and Manchester Railway. This was too complicated for their purposes; the immediate need was for a simple signal communication between the Liverpool station and a rope-haulage engine house at the top of a steep incline through a long tunnel outside the station. Rope-haulage into main stations was common at this time to avoid noise and pollution, and in this case the gradient was too steep for the locomotive to ascend unaided. All that was required was a few simple signals such as an indication to the engine house to start hauling. Cooke was requested to build a simpler version with fewer codes, which he did by the end of April 1837. However, the railway decided to use instead a pneumatic telegraph equipped with whistles. Soon after this Cooke went into partnership with Wheatstone.

In May 1837 Cooke and Wheatstone patented a telegraph system which used a number of needles on a board that could be moved to point to letters of the alphabet. The patent recommended a five-needle system, but any number of needles could be used depending on the number of characters it was required to code. A four-needle system was installed between Euston and Camden Town in London on a rail line being constructed by Robert Stephenson between London and Birmingham. It was successfully demonstrated on 25 July 1837. This was a similar application to the Liverpool project. Euston needed to signal to an engine house at Camden Town to start hauling the locomotive up the incline. As at Liverpool, the electric telegraph was in the end rejected in favour of a pneumatic system with whistles.

Cooke and Wheatstone had their first commercial success with a telegraph installed on the Great Western Railway over the 13 miles (21 km) from Paddington station to West Drayton in 1838. Indeed, this was the first commercial telegraph in the world. This was a five-needle, six-wire system. The cables were originally installed underground in a steel conduit. However, the cables soon began to fail as a result of deteriorating insulation and were replaced with uninsulated wires on poles. As an interim measure, a two-needle system was used with three of the remaining working underground wires, which despite using only two needles had a greater number of codes. But when the line was extended to Slough in 1843, a one-needle, two-wire system was installed.

From this point the use of the electric telegraph started to grow on the new railways being built from London. The Blackwall Tunnel Railway (another rope-hauled application) was equipped with the Cooke and Wheatstone telegraph when it opened in 1840, and many others followed. The one-needle telegraph proved highly successful on British railways, and 15,000 sets were still in use at the end of the nineteenth century. Some remained in service in the 1930s. In September 1845 the financier John Lewis Ricardo and Cooke formed the Electric Telegraph Company. This company bought out the Cooke and Wheatstone patents and solidly established the telegraph business. In 1869 the company was nationalised and became part of the General Post Office.