World War I Early Warning Acoustic Mirror 60m East of Boulby Barns Farm
County Council (Unitary)
Redcar and Cleveland Borough Council
Middlesbrough South and East Cleveland
SE754754 (475363, 519113)
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Due to the threat of attack by Zeppelins this sound mirror was erected in 1916 along with two others along the North East Coast, one of which is now in a Redcar Housing Estate and is listed on this website, the other I have no idea where it was. On their own they could indicate the direction of approach of the enemy aircraft but if they worked in pairs they could also work out the position of the aircraft. This particular one at Boulby was positioned some 600 metres from the cliff edge to exclude noise from the sea. Boulby cliffs are the highest cliffs on the east coast of England and from this location the sound mirror would have been able to give warning of Zeppelins approaching Skinningrove Steel Works. The Steel Works were a strategically important industrial target which during WWI also produced TNT and Mustard Gas. There were several fatal accidents with regard to this production and the graves of those involved can be found in Brotton old cemetery including two Australian munition workers who were part of the skilled labour force which this process required.
John D Hunter, 8 July 2013
I have since found out that there were in fact six sound mirrors along the North East Coast,four of which still exist. These are at Boulby, Kilnsea, Redcar and Sunderland. The other two which have since been demolished to make way for housing were at Hartlepool and Seaham
John D Hunter , 10 September 2013
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