The line-of-sight distance between relay stations was limited by geography and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private. This system was much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. They would pass the message on to the next tower. Operators at each tower would watch the neighboring tower through a spyglass, and when the semaphore arms began to move spelling out a message. Lines of relay towers with a semaphore rig at the top were built within line-of-sight of each other, at separations of 5 to 20 miles. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries. Information is encoded by the position of the mechanical elements it is read when the shutter is in a fixed position. On the 13 September 1847 the stations' crews received their redundancy notices and were finally stood down on 31 December 1847.A semaphore telegraph is a system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Wires were laid alongside the LSWR line into the Royal Clarence Yard at Gosport and then by submarine cable under Portsmouth Harbour to HM Dockyard Portsmouth. The mechanical Semaphore was finally overtaken by modern technology in 1847 with the coming of the Railways and the Electric Telegraph. The station crew consisted of an RN Lieutenant and a Handyman - or Signalman - who was often a retired sailor. There was no well and all water had to be transported by the station's own water cart for which a horse had to be hired. The telescopes were located in tubes set in holes cut through the walls. The Semaphore room was 8 feet by 7 feet 9 inches and sat on top of the building which was unique to this station. The roof was slated and the walls were rendered brick. The one at Portsdown was an ordinary looking country bungalow of five roomsĮach about 13 feet by 11 feet. There were four different designs to suit the different geographical locations. The new Semaphore Stations were of far more substantial construction than the Shutter Stations Lumps Fort - Southsea (needed to avoid the smog of Portsmouth) The cost of maintaining the stations was £3,000 per annum. After much delay in acquiring land and with building work, the stations began working at the end of June 1822. Royal George - was instructed to carry out a survey of the route of the old Portsmouth Shutter line with a view to working it with Popham's semaphore. On 19 February 1818 Mr Thomas Goddard, a Purser from the Royal Yacht. The Semaphores were made by Messrs Maudslay and the telescopes were supplied by By July 1816 an experimental line had been constructed between the Admiralty and Chatham and was in working order. His idea was to use two signalling arms, instead of the three used by the French, at different heights on a mast 30 feet high. There were various designs submitted for the new Semaphore Telegraph, but the Admiralty chose a design by Rear-Admiral Sir Home Riggs Stations were not the same as those of the old Shutter stations. In most cases the location of the new Semaphore Semaphore opened, Portsmouth was without a telegraphĬommunication. Shutter Line was closed until the end of June 1822 when the Were to be a permanent replacement for the Shutter Telegraph described Of Parliament was passed enabling the Government toĪcquire land for the new Semaphore Telegraph Stations.
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