The year was 1796 and the political unrest in France was causing considerable concern to the British Admiralty. They were particularly worried because messages between Admiralty Headquarters in London and the fleet based at Portsmouth were taking, at the very best, 4.5 hours to be delivered by horsemen.

They knew only too well that the French were leading the way with their new methods of communication – by the end of 1792 an astounding new system of signalling had been developed by the six brothers Chappe using ‘levered semaphores.’ Stations could be situated in towers located nine to ten miles apart and were able to send messages over hundreds of miles at around 1.75 words per minute.

Experiments had already been carried out in England – the Reverend John Gamble had invented such a machine and had been sent to Portsmouth to carry out trials. This was a 5 shutter machine allowing 32 (2 power 5) different signals. It was erected on Portsdown and on 6th August 1795 he reported that it was complete and in working order. However, the Admiralty decided to use a design by Reverend Lord George Murray instead. This machine consisted of 6 shutters in two columns in a vertical frame 20 feet high. Each shutter could be either closed or open which gave 64 different permutations (including all open and all closed). During September 1795 successful experimental trials were carried out on Wimbledon Common. Murray was awarded £2,000 for his invention, and Mr. George Roebuck was made Superintendent of Telegraphs on a salary of £300 per annum.

The Admiralty to Portsmouth telegraph became known as the ‘Portsmouth Shutter Telegraph Line’ and during March 1796 work commenced on building it. It was ready just a few months later. There were 10 signalling stations. These are listed together with their modern location:

1 Roof of the first Lord’s house – Whitehall
2 Chelsea – Royal Hospital
3 Putney – near Telegraph Inn
4 Cabbage Hill – near Chessington Zoo
5 Netley Heath – ‘Telegraph’,Blind Oak Gate
6 Hascombe – Telegraph Hill
7 Blackdown – Tally Knob
8 Beacon Hill – Harting Down
9 Portsdown Hill – Cosham Road Junction
10 Portsmouth – Southsea Common

Model of early Telegraph Station on display at the Royal Signals Museum at Blandford

This type of telegraph was obviously vulnerable to fog and other meteorological difficulties. The builders of the Lines were perfectly well aware of this, and went to considerable lengths to build stations that were as high as possible and clear from local fog conditions. The stations were located between 10 and 14 miles apart. The telegraph was able to work throughout the hours of daylight on at least 200 days per year.

It seems that the Telegraph was never meant to be permanent but was intended for use only until the end of the Napoleonic Wars, as the construction of the signal stations was little better than a sturdy hut with two rooms and a coal shed.

It was very successful however taking about 7.5 minutes to send a signal from Portsmouth to London.

There were probably four men at each station. Two men watched through telescopes – called Glassmen – for a signal from the stations on either side of them. When they saw the signal ‘all shutters closed’ or 123456, they would call the two ‘Ropemen’ who would operate the station’s shutters to relay the message along the line. The Glassmen and Ropemen would have interchangeable jobs and one of them would be the Foreman. There may or may not have been a RN Officer with them. Data-compression was used in the form of omitting the vowels in common words.

The preparatory signal could be sent from London to Portsmouth, and be acknowledged in just two minutes; an early version of the “ping” – this really is rather impressive.

By the end of 1796 lines had been completed between London & Portsmouth and London & Deal. By May 1806 a Plymouth extension was in operation and June 1808 saw the completion of a London to Yarmouth line.

On 18th May 1814 peace was proclaimed and Napoleon was banished to the Isle of Elba. On 6th July 1814 the Portsmouth Shutter Telegraph line was ordered to ‘immediately discontinue’. Napoleon had other ideas. He escaped from his prison island and landed in France on 1st May 1815. Once again England was at war and the Portsmouth Shutter Telegraph was re-established. Seven weeks later on 18th June 1815 Napoleon was defeated at Waterloo and ten days later on 28th June 1815 the Admiralty announced plans to establish a ‘permanent’ system of stations using Semaphore – a machine with movable arms.

The Shutter Line was finally closed in March 1816, but until June 1822 when the Semaphore opened Portsmouth was without a telegraph link.

Ted Stiles G0BHK