British Nuclear Weapons Stockpile, 1953-2013

Britain was the third nuclear power. British scientists had gotten in on the ground floor and played instrumental roles with the Manhattan Project, but the British didn’t simply walk away with a bomb for their efforts. It wasn’t until 1953 that Britain became a full-fledged member of the atomic club–blowing up parts of the Australian desert for their tests–just as the United States and Soviet Union were on the cusp of the thermonuclear revolution and its exponentially more powerful hydrogen bombs.

The chart below shows the number of nuclear warheads in the British nuclear stockpile since 1953.¹ It includes both fission (atomic) and fusion (thermonuclear) warheads.²

Numbers for the years 1953 through 1978 are known with some confidence thanks to declassified documents. John Walker drew on documents declassified in the past few years to make these counts. The numbers for later decades are harder to pin down thanks to thick layers of government secrecy. The estimates used here are by nuclear experts Robert Norris and Hans Kristensen.

With nuclear weapons, of course, numbers don’t tell the whole story. There’s a whole host of reasons that some nuclear weapons are more effective than others, including the explosive power of the warhead, the range and accuracy of the method of delivery, and how easy it is for an enemy to destroy nuclear weapons before they can even be fired, dropped, or detonated.

The British independent deterrent force has, in the course of its lifetime, consisted of several different types and generations of nuclear weapons (nine, as it happens). Some were home grown. Some were modified versions of US warheads. And some were unmodified US warheads.

Early on, they were mostly bombs to be dropped by Royal Air Force or Royal Navy bombers. After the cancellation of the Skybolt project in late 1962 and its replacement with Polaris submarine-launched missile system, the British nuclear force shifted from entirely airborne to a mix of airborne and seaborne. As of 1999, it is entirely seaborne, consisting of the TRIDENT II submarine-launched ICBM system.

The spike in numbers for 1967 was due to an overlap as a few older generations of weapons system were phased out and new generations were phased in. The ones being phased out were known as Red Beard, Yellow Sun MK2, and Blue Steel, all of which were Royal Air Force. They were replaced in part by an update known as WE 177. And the British Navy was bringing its Polaris missiles online in 1967-68.³

But the British nuclear stockpile wasn’t the only stockpile available to British military forces through much of the Cold War. Thanks to the close ties forged in the so-called special relationship, there was an unusual arrangement whereby the United States held a sizable stockpile of warheads in custody for the British, who operated the delivery systems. Some of those warheads were in the UK, but most were with British forces in Germany. Not all of them were missile warheads; many of them were for short-range tactical, battlefield rockets, demolition munitions, and gravity bombs. This stockpile was available to British forces from 1958 to 1991, when the arrangement was ended as the United States drew down drastically its nuclear forces based outside the United States.

With the two stockpiles combined, the stockpile of nuclear weapons that the British could draw on directly looked more like this.

Postscript

Scottish voters ultimately voted against independence in the referendum on September 18, 2014, but if the vote had gone the other way Britain may have been forced into giving up its independent nuclear deterrent because the Trident submarines might lose access to their Scottish home port. Here’s an interesting article on it.