Murray Shutters

Yesterday’s The One Show featured the National Museum of the Royal Navy at Portsmouth Dockyard with Dan Snow demonstrating the use of shutter signalling during the age of Nelson.

Shutter telegraph machines were vertical wooden frames with 6 shutters within them, designed by the Reverend Lord George Murray. To make a signal, the shutters were opened and closed in order to spell out different letters. This was a new means of fast communication in the 1790s and meant that the Royal Navy could now send any message between important ports and the capital.

The Portsmouth Shutter Telegraph line was built 222 years ago in March 1796. It established a line of communication between the Admiralty building in London and Portsmouth. The message was passed through several telegraph stations including Putney, Chessington, Haslemere, Bedhampton, and ended next to the King’s Bastion, Portsmouth. Workers at the stations would watch through telescopes and take down the message, then pass it on by pulling ropes attached to the back of the shutters to spell it out. This line could send important messages from the Royal Naval base in Portsmouth to London in 7.5 minutes, far quicker than any other method of communication at the time. The next fastest method was to carry a message by horse, which would take at least 4.5 hours. One telegraph station’s journal even notes that a message was sent from London to Portsmouth in one minute.

The signal system was, however, very dependent on the weather. Poor visibility could slow down messages considerably. The stations could also only operate in the daylight.

The Model
In the collection at the NMRN is a model of the ‘Glacis Station’ at Portsmouth, Southsea Common. The Hampshire Antiquary Vol. 1 (1891) states that ‘The one at Southsea Common was kept at work all day long’ and transmission of messages was as ‘quick as a cannonball’. It was taken down by early 1826 when a new system of semaphore signalling had been taken up instead. The first semaphore tower was built in the Dockyard in 1822.

HMS Hermes returning from the Falklands