YORK was in the cross-hairs of an Armageddon hit list during the icy tension of the Cold War – leading to the city relying on a top-secret device for its protection.

New findings uncovered by English Heritage have revealed exactly how AWDREY – the nickname for the Atomic Weapons Detection Recognition and Estimate of Yield system based at a nuclear bunker in Holgate – played a vital role in the UK’s defence network during the chilling stand-off.

The organisation, which now runs the bunker in Monument Close as a visitor attraction, says AWDREY’s cutting-edge technology was developed in the late 1960s to help the Royal Observer Corps (ROC) report on the effects of atomic explosions and their radiation levels if the unthinkable happened.

When defence chiefs placed York on a list of likely targets for a Soviet Bloc attack, the system was brought in to ensure the ROC could carry out its duties even when the bunker was unmanned.

And an article published in the English Heritage Historical Review 2008 has shed new light on York’s Cold War past and the importance of AWDREY, which remains intact to this day – making the bunker the only one in the UK where the device can still be seen.

The article’s author, Roger Thomas, who works for English Heritage as an expert on 20th-century military history and is from Selby, said the system was developed when it became clear key defence personnel would not have time to reach their impenetrable battle stations in the event of an attack.

He said: “Defence chiefs predicted the city would be subjected to two ground burst warheads of up to three megatons and an aircraft strike by two one-megaton ground burst bombs.

“Needless to say, that would have completely obliterated the city.”

The result was AWDREY, which, using a sensor mounted on the bunker’s roof, was designed to allow nuclear blast impacts to be assessed.

“Most people never knew the bunker existed and fewer still had any idea that the city was on the nuclear hit list,” said Roger.

“AWDREY is a remarkable relic of a very secret war. It’s in the nature of these things that we can only really tell the full story many years after.”

The semi-sunken York bunker was one of only 12 of its type built in the UK, before being stood down from operational use in 1991, when a non-aggression treaty was signed between NATO and the Warsaw Pact.

English Heritage spent six years restoring the building, which still boasts many of its original fixtures and fittings, right down to pencils and log books.

It is open to the public on the first and third weekends of the month between 10am and 4pm.

Entry costs £5 for adults, £4 for concessions and £3 for children and more information is available by phoning English Heritage on 01904 646940.