Navy planned Midget Submarine to plant Atomic Bombs in Russia
The Royal Navy planned to build midget submarines capable of planting a nuclear weapon inside Russian harbours, documents newly released at the Public record Office have revealed. Designs were drawn up for the so-called X-craft, which was a development on similar devices that had been used in the 1939-1945 War on missions, including the crippling of the German battleship, Tirpitz.
The idea of carrying an atom bomb into an enemy port, dropping it and detonating it on a long timer, seemed to answer an increasingly desperate need for the post-war Navy. The Admiralty had watched the development of Britain's nuclear deterrent with increasing alarm because the only method of delivery was by air, with the V-bomber force of the RAF.
By 1955, when the 'atomic' X craft design was first discussed, the Navy was still at least 10 years away from launching a vessel - submarine or surface - that was capable of delivering a nuclear weapon. Even the American Navy was nowhere near ready to fire atomic warheads from the sea and in Britain the historic rivalry for funds and prestige between the Royal Navy and RAF was at a post-war peak. Operation Cudgel, as it was code named, seemed to give the Navy a quick answer to the problem of how it was to get a slice of the huge budget that Britain was devoting to nuclear strategy in the Cold War. It also took advantage of the fact that Britain's first test of a nuclear weapon, in 1952, was conducted by placing a boat in a natural harbour in the Monte Bello Islands off Australia and recording the expected effects of placing a bomb against such a target. So the enthusiasm detectable in the records, due to be kept secret until 2020 but released early under the Open Government Initiative, is easy to understand.
The files also show the obsessive secrecy surrounding Cudgel. Several of the messages passing within Admiralty departments were written by hand because not enough typists with top security clearance could be found. Capt. P.J. Cowell, director of Undersurface Warfare, was the driving force behind Operation Cudgel, telling colleagues that,
the existing X-craft as built today (is) too complicated and too large for the purpose. A specially designed craft is necessary, whose sole function is to deliver the atom bomb and return the crew to the parent (submarine).
The detailed requirements for the X-craft, which are set out in the PRO documents, show that the vessel was intended to be carried to a drop-off point off an enemy coast by a large Porpoise class submarine. Then the submarine and its crew of two would travel for up to 150 miles to its intended target. The crew would then prime, arm and detach their 'Red Beard' nuclear weapon. The atomic bomb would be designed to float in relatively shallow water. Once planted the device would be timed to detonate up to a week after being delivered, according to the documents. It was specified that the submarine should be able to operate in very low temperatures, indicating that the principal targets for the weapon would be the Arctic Ocean Ports of the Soviet Union like Murmansk and Archangel.
The X-craft would have been ready by 1959, giving the Navy a nuclear capability some six years before it actually achieved it. The project seems to have started well, with the Atomic Weapons Research Establishment at Harwell, Oxon reporting that there was no reason why an atom bomb should not be adapted for the purpose. But there was bad news for the proponents of Cudgel when A.J. Sims, the director of Naval construction, wrote that a 30-ton craft, the most that could be carried by a conventional submarine, built using a non-magnetic material and with the endurance required, could not be made.
Despite this, further discussions took place into 1956 and detailed drawings of the new craft seem to have been made. But then an abrupt halt was called, when in July of that year, Patrick Nairne, Secretary to the Board of the Admiralty, wrote to Capt. Cowell to report a meeting of the Navy's masters. "I am to acquaint you that Their Lordships have approved the following policy with regard to X-craft.
(a) Development of neither nuclear nor conventional weapons for X-craft is justified.
(b) Present X-craft are to be retained and continue to operate.
(c) No further X-craft will be built.