The London to Portsmouthcanal was a proposal for the construction of a secure inland canal route from the capital London to the headquarters of the Royal Navy at Portsmouth. It would have allowed craft to move between the two without having to venture into the English Channel and possibly encounter enemy ships. There is no naturally navigable route between the two cities, resulting in several schemes.
In 1810, the Earl of Egremont began to promote the idea of a canal to link the Rivers Wey and Arun, separated by only 15 miles. Part of the justification for this canal through a very rural area, with few of the cargoes which had made other canals profitable, was to provide an inland route from London to the south coast of England, utilising these two rivers and the Portsmouth and Arundel Canal. This was considered an important consideration as England was at war with France and thus coastal shipping at risk of attack. Josias Jessop was appointed consulting engineer and made an estimate of £72,217 for construction of the canal, later increased to £86,132 when part of the route was changed. A survey was carried out in the same year by Francis and Netlam Giles for an alternative route, from the Croydon Canal to Newbridge, via Merstham, Three Bridges, Crawley and Horsham. An Act of Parliament received the Royal Assent on 19 April 1813, entitled "An Act for making and maintaining a navigable Canal, to unite the Rivers Wey and Arun, in the counties of Surrey and Sussex". This authorised the construction of the canal from the Godalming Navigation near Shalford, south of Guildford to the northern terminus of the Arun Navigation at Newbridge. May Upton was appointed resident engineer in July, and work began. Construction was completed in 1816. The route of the canal was 18.5 miles with 23 locks. By the time it was opened, however, the war with France was over and thus one of the key reasons for its construction was removed. As a result it was never very prosperous, but did reasonably well, with a maximum of 23,000 tons carried in 1839. However, railway competition hit hard in 1865 with the opening of the Guildford and Horsham Railway, which was in direct competition with the canal. There were also engineering problems with few sources of water to tap into, compounded by porous soil on the summit level, which led to water shortages. An Act of Abandonment obtained in 1868 authorised closure. It was offered for sale in 1870, but officially abandoned in 1871, with the land sold to many along its route.
