This powerful 7.2kW ex-cold-war air-raid siren now sits forlorn, siezed solid, never again likely to herald the announcement of impending thermonuclear warfare, or to sound the tests which prepared for it. Left to rot at the end of the 1980's instead of being removed with the rest of Britain's Civil Defence infrastructure, it remains a mute reminder of what might have been. The junction boxes at the end connect to 1kW heating elements, preventing the siren vanes from freezing up in cold…