Redcar Coastal Watch Mirror

Long time readers of Fabulous North may have seen our previous post about the coastal watch mirror at Fulwell. These acoustic mirrors were built along the UK coast during World War I as an early warning system, detecting sound from German Zeppelins up to 15 minutes away. A type of microphone would have been positioned on the plinth in front of the mirror and an operator hiding in a nearby trench would have heard the sound of the Zeppelins through headphones. The plinth is still intact at both the Fulwell and Redcar mirrors.

Redcar coastal watch mirror was built during WW1 in 1916, and was invented by Major William Sansome Tucker. Airships could be detected by the sound mirrors as they moved relatively slowly, however, with the development of faster aircraft and the use of radar, the sound mirrors were no longer used by the early 1940s.

There is a plaque in front of the Redcar mirror which explains more:

REDCAR EARLY WARNING STATION

This structure is a Sound Mirror or detector, built by the Royal Engineers in 1916. It was part of an extensive Zeppelin and enemy aircraft detection system deployed down the East Coast of Britain druring the First World War. Zeppelins raided the North East Coast 15 times between April 1915 and November 1917. The sound of approaching aircraft was reflected off the concave 'mirror' surface and received into a trumpet mounted on a steel column. The trumpet was connected to a stethoscope used by the operator or 'listener', and the part of the dish that produced the most sound indicated the direction of the approaching aircraft. Advanced warning of an imminent attack could then be given to local people. By the early 1940's sound detection technology was being replaced by 'reflective detection finding' now known as radar.

There are very few coastal mirrors still standing in the UK, and most are of the coast of Kent. Closer to the North, there is one at Boulby and Kilnsea in Yorkshire and Fulwell Coastal Watch Mirror near Sunderland. All fascinating pieces of recent history.