PEOPLE SEE THEM EVERY DAY - BUT WHAT ARE THESE STRANGE CONCRETE BLOCKS?

Dave Robson, Gazette Newspaper, January 2019


One stands in a farmer’s field, the other on a Redcar housing estate - but not everyone knows what they are.

Now these curious concrete structures have been receiving a fresh wave of national publicity thanks to a photographer’s labour of love. Fuelled by tales of his grandad’s involvement in radar development, Joe Pettet-Smith set out to photograph all 13 of the UK’s surviving “sound mirrors” - pre-radar structures erected in the First World War to help detect the sound of approaching Zeppelins.

Of the 13, we have two - one at Boulby, the other in Redcar. The one in Redcar, which stands incongruously next to modern houses, is even a Grade II* Listed structure, complete with a plaque - unveiled in 2001 - telling its story. And while they’ll be familiar to some, Joe believes many people still won’t really know the story behind them. But after his photos were published by the BBC earlier this week, there’s been a renewed wave of interest.

Built in 1916 by the Royal Engineers, the Redcar “listening post” stands on the corner of Holyhead Drive and Greenstones Road. The 4.5 metre concrete and ballast slag structure operated until World War Two, with volunteers using stethoscopes to pick up sound signals reflecting onto a steel column off its concave face. The Redcar sound mirror - and the other 12 that survive - were then replaced by radar. 

Professional photographer Joe, 25, of Brighton, said he felt duty-bound to record them for posterity - even using an old-fashioned format plate camera for added authenticity, and out of respect for the people who built and operated them. He said: “The Redcar one was originally built on marshland, away from people and houses, because there wouldn’t be as much noise pollution. “Now it’s in the middle of a housing estate, which makes it feel very special somehow.

“The science behind them was solid, because concave structures amplify sound... But whereas airships were slow and noisy, as planes got quicker and quieter, that’s when radar started to take over and they weren’t needed any more.”

©Gazette 2019 - This text is for research purposes only, no copyright infringement is intended.

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