KELVEDON HATCH - Secret Cold War bunker
Mon 15th Mar 2021
My new book about the Cold War reveals how a secret underground bunker came to be built in the Essex countryside in the early 1950s as a key part of Britain’s defences against Soviet nuclear attack. Here is the full story of the origins of Kelvedon Hatch…
On Monday morning, March 9 1953, a Bedford coach carrying a small contingent of national servicemen from RAF North Weald turned off the Brentwood to Chipping Ongar road, lumbered half a mile down a long, winding farm track, then disappeared into a wooded copse studded with impressive silver birch, ash and rowan trees.
The vehicle pulled up in front of a chalet-style bungalow, which did its best to blend in with its surroundings, and to a passing walker – if any had been allowed – might just have seemed like a farm dwelling of the modern variety.
But the bungalow was no innocent rural habitat. It was a guardhouse. And the men who alighted from the vehicle were not a group of arborists, or botanists, or country ramblers. Instead they were an advance party of teleprinter operators and fighter plotters, about to start work on day one in a top-secret underground bunker which would have a critical role to play on that fateful day when Soviet Tu-4 bombers swooped over the Channel with their atomic payload on board.
If that apocalyptic moment came to pass, Kelvedon Hatch, hidden away in the gentle Essex countryside, would be in the front line of the nation’s vital air defences as the RAF’s Metropolitan Sector Operations Centre, coordinating the work of nearby radar stations, and directing fighter planes from the area’s airfields towards the enemy.
Kelvedon Hatch - one of six command and control centres around the country - was the jewel in the crown of the government’s top-secret OPERATION ROTOR programme - a badly-needed modernization of the country’s early warning and detection system, which had either been only very basically maintained since the end of WW2, or simply abandoned.
ROTOR, approved by the Air Council in June 1950, was a massive military engineering project, revamping the whole of the radar system and placing a network of control and operation rooms like Kelvedon Hatch in large, protected – usually buried – bunkers in the British countryside.
Deemed critical to the nation’s defence back in 1950, ROTOR seemed even more relevant in the wake of the Korean War. It was then promoted to ‘super priority’ status in August 1952 – equal to that of the development of atomic weapons and guided missiles – after a sobering analysis of Britain’s readiness for war in a major policy paper drawn up by the Chiefs of Staff, entitled Defence Policy and Global Strategy.
Global Strategy declared unequivocally that ‘the Free World is menaced everywhere by the implacable and unlimited aims of Soviet Russia. Using Communism as a convenient and dynamic instrument, Imperialist Russia seeks world-domination exercised from the Kremlin’.
If the crunch came, the opening phase would be of ‘unparalleled intensity’. The Soviet Union would attack the United Kingdom with atom bombs, hoping to neutralize the most threatening bomber bases from which US atomic attacks on Russia could be launched.
After the report came out, Air Ministry officials scouted around in the summer of 1952 for venues for their new underground Control and Reporting centres. Secluded Kelvedon Hatch, just 25 miles from London and six miles from RAF North Weald, was quickly identified as strategically and geographically suitable so officials approached the farmers whose land they wished to compulsorily purchase.
Arthur Parrish and his son Jim, farmers and market gardeners, were obliged to hand over 13 acres of pasture land, ten acres of Highash Wood, and half an acre for a private roadway the military could construct in the corner of the wood. The Parrishs were paid £100 an acre, but Jim had no complaints. ‘I’ve fought two world wars and I have no desire for a third’, he told the men from the ministry.
Building work began in late summer, with RAF guards positioned on top of the hillside overlooking the copse to ward off the curious. The hillside was bulldozed to a depth of 125 feet, at the bottom of which 20 feet of gravel was placed to act as a shock absorber and aid drainage.
Concrete walls ten feet thick were erected, reinforced with one-inch thick tungsten enhanced rods. Over these walls a lining of brick and pitch waterproof membrane was laid, and on top of that was placed wire mesh netting called a Faraday Cage. When an atomic bomb goes off it creates an electromagnetic pulse which wipes out all things electric. The Faraday Cage would provide an ‘electric field-free’ space inside the Kelvedon bunker, protecting the sensitive electronic and communications equipment inside. All internal doors on the ground floor were lined with metal plates.
Having built the bunker, the workmen pushed the tons of dirt back over the top to bury it. Once the grass had grown back the hill was, to all outward appearances, the natural part of the landscape it had always been. The 27,000 sq. ft bunker, 20 feet below the surface, was completely hidden from prying eyes.
Inside the bunker was on three floors. The operations room was located in a large central well stretching up through all three floors. On the bottom floor stood two large map tables. One, 24 feet across, was the General Situation Map, displaying the big picture, covering a region stretching from the Humber to Southampton and across the sea to France and Denmark. The smaller, 10 feet across, was the Fighter Table, showing more localized aircraft firmly under Kelvedon Hatch’s control.
The maps were the domain of the fighter plotters, who moved aircraft around the map with rods - like croupiers on a roulette table. Those gazing down on the maps from glass-paneled cabins, built into three walls on the middle and top floors, took their places in order of importance.
On the middle level were the Ground Executive, who gave instructions to radar stations, and the Air Executive, who directed airborne planes. The most senior officers – chief fighter controller, guided weapons controller, battle commander and electronics officers – occupied the top floor.
Finally, stretching from floor to ceiling for all to view, was the all-important Tote Board, the central source of up-to-the-minute information with aircraft availability and weather reports from airfields in the sector such as North Weald, West Malling, Biggin Hill, Manston, Tangmere, Bentwaters, Waterbeach and Marham. If an unidentified aircraft entered their air space, the plotters could turn to the Tote Board and know exactly how many airfields had planes that could be scrambled immediately, or ready within 15 minutes.
Although ‘The Hole’ – as Kelvedon was quickly christened by its staff – was ‘activated’ on that day in March, it would be May before it was fully up and running. The devastating North Sea flood of January 31 – which had ravaged the Suffolk and Essex coast - had caused serious delays in men and equipment.
When it was totally operational, Kelvedon could not have wished for better senior officers in charge - both heroes of World War 2. New Zealander Alan Deere, Commanding Officer of RAF North Weald, was one of the outstanding fighter pilots in the war, earning the Distinguished Flying Cross (DFC) for covering the retreat to Dunkirk.
The tall, angular Acting Air Vice Marshal Thomas Pike had flown Bristol Beaufighters from RAF Tangmere, playing a leading role in the air defence of the United Kingdom, shooting down enemy aircraft and – like Deere – winning the DFC and Bar.
By May some 500 personnel – almost all men – were employed at Kelvedon Hatch, with 100 down in the bunker at any one time. Nearly all were based in a camp at RAF North Weald, where they lived in prefabricated huts.
For some the exercises they took part in felt very real – for others they were just war games, ‘fairly remote from the actual picture’. All had signed the Official Secrets Act, but day-to-day security was not overburdensome. There was no special pass needed to enter the bunker – or indeed certain rooms in it. A uniform and an RAF 1250 pass were enough to get you on the bus from North Weald and virtually guaranteed entrance to Kelvedon Hatch after that.
‘On reflection I realized security was quite lax – surprisingly after the efforts to hide ‘The Hole’ in the first place’, recalled one fighter plotter. ‘I knew the majority of people on the bus or at the site, but there were always a few strange faces around – RAF personnel, new postings, auxiliaries, detachments. The acquisition of a uniform and a fake 1250 pass would not have been difficult. Having flourished the identification and gained entry, an agent could note any items of interest, leave ‘sleeper’ devices or carry out any number of undercover activities’.
The imagination may have run a little wild – but these were nervous times. Raymond Parmenter was an MT (motor transport) driver, seconded to the coach unit, and at Kelvedon Hatch from the very start.
‘ Certainly I knew this whole project was something unusual – but then you must remember as a young man, what was usual? The second bloody world war had only finished eight years earlier: London, my working and social environment, was almost a ruin, and men women and children were terribly scarred – if not physically, then most certainly mentally, by six years of war’.
Kelvedon Hatch cost a million and a half pounds to build, and the whole ROTOR network of 54 radar stations and control centres cost a staggering £240 million. It used up 350,000 tons of concrete, 20,000 tons of steel and thousands of miles of telephone and telex connections.
The employees of ‘The Hole’ might have had some degree of protection if the atom bombs got through and began to fall – but what of the prospects for the general population? In the same week that Kelvedon Hatch was activated, the government’s Home Defence Committee decided to commission a report on the likely conditions in Britain during the initial ‘survival’ phase of a future war, when the nation would grimly hang on after nuclear attack.
A committee was set up under the chairmanship of Robert Hall, Head of the Cabinet Office’s Economic Section, called the ‘National Economy in War Working Party’. Hall and his colleagues had to work on the basis that the Soviets possessed a stock of 200 atomic bombs to hurl at this country.
Hall’s findings, published in late July, read like something out of a dystopian novel. A successful Soviet attack would kill 1.4 million, leave ten million people homeless, and authority would collapse.
Within years, UK government planners had to confront the even more terrifying H-bomb era. Then Kelvedon Hatch would be upgraded to a yet more vital role – that of an HQ of an emergency regional government. In the event of Armageddon, politicians and civil servants would live like moles underground to try and maintain what was left of the East of England – after most of the rest of us had perished.
* The Kelvedon Hatch Secret Nuclear Bunker museum will be re-opening soon following the lockdown. As well as the story of 1953, its later role as a seat of regional government in the event of nuclear war is fully told – many of the offices, bedrooms, even a hospital theatre are kept as they were then.
* Two Minutes to Midnight – 1953, The Year of Living Dangerously is published by Biteback.