The history of Chatley Heath Semaphore Tower

1747-52 Roy Military Map of Scotland

A mid-19th century tower

The Semaphore Tower stands deep in ancient heathland near Wisley in Surrey. This unique remnant from the Napoleonic era was once a vital link in a signalling chain that transmitted messages from Admiralty House in London to Portsmouth Docks in a matter of minutes. The construction of the line was ordered in 1816 in the aftermath of the Battle of Waterloo, when foreign invasion still seemed a real possibility.

For over 20 years the urgent affairs of the Royal Navy passed back and forth along this line, relaying orders to the fleet and reporting the movements of friend and foe alike. If things had turned out differently – if there had been another war with France, if England had been invaded – this Tower in Chatley Heath might have played a key role in a great naval conflict.

Sadly, like so much of our superseded military architecture, this fascinating structure is now left marooned without purpose and is decaying fast.

Pophams' Semaphore Code A-Z

The Royal Navy’s most advanced signalling system before the electric telegraph

Historically, long range military communication was a real challenge: simple hilltop beacons signalled the arrival of the Spanish Armada in 1588. As naval warfare developed across the centuries, more sophisticated signalling systems were invented using flags or moving balls, but these were slow and unreliable. Semaphore was the solution; moveable arms on a mast that signalled letters of the alphabet.

The French invented the first semaphore system in 1794, but the British preferred to find their own solution. The first British coastal naval signal stations in the 1790s used either flags and balls or a system of shutters in a frame, but none were efficient in bad weather.

Rear Admiral Sir Home Riggs Popham

'England expects that every man will do his duty.'

Rear Admiral Sir Home Riggs Popham was fascinated by signalling. In 1800, Popham created the first flag system for individual letters, famously used by Nelson to declare ‘England expects that every man will do his duty.’ Later, he devised a semaphore with wooden arms for ship-to-ship signalling. Much easier to operate than the shutter system, it was soon adopted on land.

Yet in 1814, with Napoleon apparently safely confined on Elba, the Admiralty decommissioned all their signal stations. Napoleon’s escape and the ‘damn nearest run thing’ at the Battle of Waterloo made the Admiralty realise that such optimism has been misplaced. Eleven days after Waterloo, an Act was passed to acquire land for a new chain of signal systems, this time using Popham’s semaphore.

The only  five storey Semaphore tower

The Chatley Heath mast was the only station on the Portsmouth line that required a five-storey tower for visibility across the seven miles to its two neighbours. In 1822, on its completion, it was chosen to be the junction for another line to Plymouth. The stations were operated by Royal Naval lieutenants who were close to retirement. They worked with an assistant, possibly a former petty officer or wounded seaman.

Early reports of water ingress

Each station housed a lieutenant and his family. From the beginning, water ingress was a problem at Chatley Heath and many letters were sent by the first station superintendent there, Lieutenant Harries, to the Admiralty on the subject. In one such letter dated December 1826 he complained:

“Water still finds its way through centre of the mast even to the lower room.... great difficulty in getting any workman in neighbourhood to do any small jobs by the distance we are from their abode... my family and myself are almost poor hermits.”

Admiralty Semaphore Lines 1822-1847

New technology and new residential use

For over 20 years, orders and reports clacked up and down the line from Admiralty House to Portsmouth. But the railways were coming and with them the electric telegraph: in 1847, the semaphore lines were decommissioned.

After its decommission, needy retired naval officers and then local civilians lived in the tower until 1963. Left empty, it suffered vandalism and then a major fire in 1984. Surrey County Council and Surrey Historic Buildings Trust restored it well, and again let it residentially, but 30 years on the Tower is deteriorating and repair costs are escalating rapidly.

Please support our appeal and help us restore the last surviving signalling tower in Britain.

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