Hidden in plain sight just yards away from a children's playground is a chilling reminder of the threat of nuclear Armageddon.

Gravesend's secret Cold War bunker was built under Woodlands Park as part of a network of underground command posts across Kent.

It was used between 1954 and 1968 to coordinate rescue and emergency services in the event of a Soviet strike on the UK.

All centres were expected to provide information to county control at Maidstone, where it could coordinate a response with the regional war room, based at Tunbridge Wells.

In the extreme scenario of nuclear war and the firestorms and radioactive fallout that ensued, its primary functions would be to re-allocate resources based on the best chances of survival and account of war dead.

Its strategic importance was such that the command post was expected to help serve a seat of regional government should Downing Street have been paralysed in the blast.

But for most of its two-decade long operational duration the concrete structure in Gravesend retained an air of public secrecy.

Now its fascinating history has been put into print as part of an extensive research project spanning more than 10 years.

Local historian Victor Smith has produced the two-part booklet Preparing for Armageddon: The Story of Gravesend Cold War Bunker after trawling through thousands of historic records and civil defence manuals.

Speaking at a launch event held with the support of Kent County Council at Cascades Leisure Centre, he said the bunker was an important reminder of the threat of “nuclear megadeath” during the Cold War conflict.

He said: "Let there be no doubt, dealing with the aftermath of a full or even a moderate nuclear attack, with nearby targets being Tilbury docks and the power stations, as well as the Chatham naval base, would have been distressing beyond imagination.

"The rescuers themselves would have been subject to the same death and injury as the general population, all liable to begin to suffer from radiation sickness from fallout, whose symptoms are too terrifying to describe.

"There would have been grief, tears and more tears, and then nothing, just a cerebral numbness, slipping away into death."

In the event of a Soviet nuclear attack various atomic explosions were anticipated at power stations at the now demolished Littlebrook in Dartford and Northfleet, and naval targets at Tilbury, Chatham and Sheerness.

Further afield, airfield bases at West Malling and Manston could be struck, as could the Ashford railway junction and Port of Dover.

As a direct result various homes and buildings would have been relegated to piles of rubble with blocked roads and scorched ground.

Meanwhile, in Gravesend the civil defence and council offices at Woodville Terrace would have been wiped out and staff vaporised.

Mr Smith, a former manager in the British Civil Service, described the aftermath as a scenario in which "the living might have envied the dead".

The defence heritage expert went on to explain the unenviable task facing a small group of volunteer staff from the Civil Defence Corps.

Below ground the bunker team at Gravesend was made up of 35 men and women acting under the command of the Town clerk.

The post consisted of 13 rooms containing a power and ventilation plant, communications areas for the command staff and various dormitories.

Staff would be responsible for a range of tasks including compiling reports of damage and radioactive fallout and passing on messages regarding rendezvous points and routes.

Tally boards would record the available civil defence resources available, as well as the total casualties and information would be transmitted to central command at Maidstone.

However, what made Gravesend's bunker particularly unique was its location, explains Mr Smith.

A council briefing note taken from June 1954 stated that the site at Woodlands Park was "very carefully considered and, being in an open space, access could be obtained under all conditions; the maximum possible safety from fire and debris hazards also being obtained".

This was unusual as the majority of civil command posts at the time were built under existing council offices or car parks adjoining the premises.

It was a somewhat flawed logic because it meant in the event of a blast those trapped underground would have likely been encased in a radioactive tomb of rubble and debris.

In fact, a popular misconception at the time, explains Mr Smith, was that such posts were shelters for high standing council officials and mayors. But in reality he adds they would have been first to be "shown the door".

The threat of thermo-nuclear war between America and its allies and the Soviet Union had accelerated by the early 1960s.

By this time Britain could be reached by Russian ballistic missiles and shortly after from weapons deployed from submarines.

Increased tensions saw an increase in training exercises preparing for a possible attack, including at Gravesend where there were plans to expand the facilities.

However, there was also growing discontent at the nation's preparedness for such a war, as documented in Peter Watkin's controversial The War Game, filmed across Kent.

The flick was banned by the BBC for its harrowing depiction of the aftermath of a nuclear blast, including widespread looting, radioactive poisoning and death by firing squads.

Eventually by 1968 the emergence of mutually assured destruction had challenged the prevailing regime of civil defence.

The Civil Defence Corps which manned the bunker were stood down and after 1974 the stand-by function had ceased and its official use discontinued.

Gravesend's bunker was restored in the 1990s at the end of the Cold War and now acts as a museum.

It appeared in the 2011 Second World War film Age of Heroes, starring Sean Bean and James D'Arcy and also features a huge British nuclear bomb, weighing 900lbs and measuring 133 inches long, which was donated to the site.

But Mr Smith's interest in the site is not just academic.

He says for younger people the Cold War is a piece of history but remains a vivid memory for those over the age of 45 or 50.

And he believes the bunker at Gravesend is a "archaeological reminder" of governmental and popular anxieties from the time, some of which exists today.

He said: "The world which we inhabit today, has actually evolved into something more complex and, in various ways, potentially no less risky, with the possibility of new Cold Wars or a revived old one."

The historian points to various nuclear, biological and cyber threats and the competition for food and living space in the face of global warming as examples.

Susan Carey, KCC cabinet member for environment, who was among the guests at the booklet launch, said: “The Cold War Bunker at Gravesend is an outstanding example of what can be achieved by community groups especially when combined with the scholarship and passion for heritage of a local expert.

“And there are few who can match the achievements and knowledge of Victor Smith.

“From a Kent County Council perspective, I would like to thank Victor for all the work that he has undertaken on defence and military heritage from the early days of the Historic Fortifications Network, through pioneering recording of school air raid shelters and his contribution to the South East Research Framework, to this most recent publication which once again puts Gravesend on the map.”

The booklet launch was the first official engagement for Alan Ridgers, KCC’s newly-appointed heritage champion.

He said: “The research that Victor Smith has done in producing this booklet is most thorough and impressive, so I was pleased to attend its launch.

“As we are all aware, Kent has a wealth of historic buildings, some dating back thousands of years, right through to the Cold War era of the 1950s, of which the Gravesend bunker is an excellent example."

The bunker has now reopened to the public for the first time since Covid-related closures.

Visits may be booked via Gravesham's Tourist Information at info@visitgravesend.co.uk or by telephone on 01474 337600.

Mr Smith's booklet is available at the tourist information stall in Gravesend Market and the bunker.

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