A brief history of shutter towers

Shutter towers are mechanical signalling devices. When combined in a line, they make up a visual telegraph system that can convey messages over long distances. Shutter towers were used to convey information, including the time of day, between cities.

Visual telegraph systems were first developed in France by Claude Chappe and his four brothers, they were soon utilised and adapted by the British into shutter towers that use six black and white mechanical flags.

Shutter towers were used, in England, during the late 1700’s and the early 1800’s.

The British admiralty used shutter towers to communicate between:

• The Admiralty, London and The Glacis, Portsmouth (which opened in 1796)
• The Admiralty, London and Sheerness, and Deal (which opened in 1795)
• The Admiralty London and Great Yarmouth (which opened in 1808).

The Admiralty London shutter telegraph system
The Admiralty London shutter telegraph system consisted of 63 shutter tower stations. Interestingly, the number of different signals that can be conveyed using a six panel shutter tower is also 63.

On a clear day information could be conveyed at speeds between 3000 and 7200 kilometres per hour, depending on the distances between towers. The towers were, at worst, 300 times faster than a relay of riders on horseback. However, the towers were very costly to run, and were eventually surpassed by semaphore towers, and later the electric telegraph.

Further reading

The Semaphore
By T.W. Holmes
Published by Arthur H Stockwell Ltd, Elms Court, Ilfracombe, Devon, England.
ISBN 0 7223 1629 1

Military Signals from the South Coast
By John Goodwin
Published by Middleton Press, Easebourne Lane, Midhurst, West Sussex, GU29 9AZ England.
ISBN 1 901706 54 0

The Story of Chatley Heath Tower
By John & Beryl Skelly
Published by Surrey County Council, England

Send it by Semaphore (the old telegraph during the wars with France)
By Howard Mallinson
Crowood Press, Ramsbury, Wiltshire, SN8 2HR, England
ISBN 1 86126 734 7

The Old Telegraphs
By Geoffrey Wilson
Published by Phillimore & Co Ltc, Shopwyke Hall, Chichester, England
ISBN 0 900592 79 6

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