Britain’s secret nuclear bunker: Buried 100ft down inside is the control room where the order to launch a strike would be given
Andrew Preston is given unprecedented access to Northwood, the UK military’s nerve centre
There’s a hiss of compressed air as the two bolts ease across and the reinforced-steel airtight door opens to reveal the home of Combined Task Force 345.
This secret operations room controls the submarines that carry our nuclear deterrent.
One of four Vanguard class or ‘bomber’ submarines carrying Trident II D-5 missiles is constantly on patrol, silent and undetected.
Every missile has a range of 7,000 miles and can deliver 12 warheads, each of which is eight times more powerful than the bomb used at Hiroshima. It is from here that the instruction to fire would be passed on to the submarine.
Unsurprisingly, it’s submariners who feel most at home down here.
There’s no sound and no daylight in this nuclear-attack-proof concrete bunker 100ft underground, built into a hillside in the leafy London suburb of Northwood.
The temperature and humidity are controlled, and the air below ground is over-pressured so that in the event of a chemical attack outside, no toxic gases would be sucked in.
The order for a nuclear attack would be received from the Prime Minister from his bunker beneath Whitehall.
Once it had been authenticated, the message would then be encrypted and passed on to the submarine along what is called the firing chain.
The Weapons Engineering Officer on board the boat would then pull a red trigger – the same one used in a Colt 45 pistol – and a missile would be released.
To stop you getting as far as this heavily guarded control room, Northwood Headquarters, Britain’s premier military HQ, is surrounded by 12ft-high vibration-sensitive fences topped with razor wire.
The nuclear bunker itself is surrounded by two further fences with rolls of razor wire on top and motion-sensitive cameras.