HMS Meteorite was an experimental U-boat developed in Germany, scuttled at the end of World War II, subsequently raised and commissioned into the Royal Navy. The submarine was originally commissioned into the Kriegsmarine on 13 March 1945 as U-1407. She was built around a Walter engine fueled by high-test peroxide (HTP), the fuel known as T-Stoff in German service.
The three completed German Type XVIIB submarines were scuttled by their crews at the end of the Second World War, at Flensburg and and U-1407 at Cuxhaven, all in the British Zone of Occupation. U-1406 and U-1407 were scuttled on 7 May 1945 by Oberleutnant zur See Gerhard Grumpelt even though a superior officer, Kapitän zur See Kurt Thoma, had prohibited such actions. Grumpelt was subsequently sentenced to seven years' imprisonment by a British military court.
At the Potsdam Conference in July 1945 U-1406 was allocated to the United States and U-1407 to the United Kingdom, and both were soon salvaged.
U-1407 was salvaged in June 1945, and transported to Barrow-in-Furness, where she was refitted by Vickers with a new and complete set of machinery also captured in Germany, under the supervision of Professor Hellmuth Walter. Because she was intended to be used solely for trials and possibly as a high-speed anti-submarine target, her torpedo tubes were removed. She was commissioned into the Royal Navy on 25 September 1945 and renamed HMS Meteorite.
The Royal Navy was attracted by the air-independent propulsion potential of U-1407. The boat arrived secretly at Vickers Yard in Barrow-in-Furness under tow in poor internal condition. It received pennant number N.25 on 25 September 1945 and was commissioned as HMS Meteorite on 26 August 1947. The submarine underwent a lengthy refit with a new Mk 17B HTP turbine engine under the supervision of Professor Helmut Walter and a team of German engineers transferred to Barrow (initially Walter and seven engineers on 1 January 1946, later expanding to 14 men with families). The refit involved a complete overhaul, new components from Germany, a new escape system, revised ventilation, replacement of all electrical equipment, and removal of the torpedo tubes. The boat was intended for experimental use, with possible later employment as a high-speed anti-submarine target if trials proved successful.
During 1946 Meteorite carried out a series of trials under the guidance of Walter and his original team from Germaniawerft, Kiel. The trials raised considerable interest in the possibility of HTP as an alternative to nuclear power as air-independent propulsion and the Admiralty placed an order for two larger experimental Walter boats based on the German Type XXVI, the s and , to be followed by an operational class of 12 boats.
Sea trials began in 1948. HMS Meteorite left Barrow at the end of January for preliminary First of Class trials off the west coast of Scotland using only diesel-electric propulsion. These trials familiarised the crew with handling and control responses and tested surface and submerged speeds, turning circles, diving, and depth-changing performance between 10 and 13 March 1948. On-shore combustion trials of the HTP turbine ran from July to September 1947, with final shore tests completed in July 1948 before the turbine was fitted aboard. Surface trials with the Walter engine continued until October 1948 (delayed by rough weather). These achieved speeds over 14 knots and demonstrated reliable turbine operation. A Royal Navy report noted the enormous operational potential of high-speed HTP submarines for evasion, while highlighting disadvantages such as the high cost and scarcity of HTP, the need for escort and storage vessels, difficulties in surface handling in rough seas, lack of astern power, and high noise levels.
Main operational trials (surface and submerged) took place between 17 March and 30 April 1949. HTP fuelling occurred from 17 to 24 March in the Barrow area, after which the boat was towed to Rothesay Bay. General handling and drills from 27 March to 1 April showed that HMS Meteorite was exceptionally difficult to handle on the surface (large turning circle, extremely limited astern power, no steering astern) but outstandingly easy and responsive when dived, although slow to change depth. Initial HTP surface trials were conducted in Loch Long, followed by main high-speed trials in Loch Ryan. The boat handled perfectly at high speeds, and submerged runs confirmed outstanding manoeuvrability. The trials successfully proved the machinery and allowed the crew to gain experience and confidence in submerged handling.
Meteorite's Royal Navy service came to an end in September 1949, and she was broken up by Thos. W. Ward of Barrow-in-Furness.