Explorer Class Experimental Submarines

For many years considerable research had been carried out in Germany into the development of hydrogen peroxide powered submarines: hydrogen peroxide is a chemical used as bleach or disinfectant and the submarines used Hydrogen Test Peroxide (HTP), a much more concentrated version. When the hydrogen peroxide decomposes is produces oxygen and steam. These two products are burnt in kerosene high pressure gases are released which are used to power turbines.

The research programme accelerated under the Nazis during the Second World War (1939-1945) and resulted in the construction of several experimental U-boats. U-1407 was one such prototype. She had been constructed by Blohm & Voss in Hamburg during 1943. Although commissioned in early 1945 she was scuttled in Cuxhaven in May the same year. Salvaged by the British she was refitted and commissioned into the Royal Navy as HMS Meteorite. Initial trials with this submarine arose considerable interest in possibility of Hydrogen Peroxide powered submarines as an alternative to nuclear power. In order to asses the practicality of such propulsion two purpose built experimental submarines were constructed.

Explorer and Excalibur displaced 780 tons surfaced and 1,000 tons submerged. For high underwater speeds they were deigned with a long, streamlined hull measuring 225 feet in length. They had a beam of 15 feet and a draught of 11 feet. As experimental submarines, they were unarmed.

Upon commissioning both vessels joined the Third Submarine Squadron on the Clyde. The Spa Class water carrier RFA Spabeck acted as a transport for the High Test Peroxide (HTP). Although in trials Excalibur and Explorer could achieve high speeds, they could only be maintained for short periods. Furthermore engine room explosions and onboard fires were frequent occurrences. The volatile nature of hydrogen peroxide earned the two submarines the nicknames ‘Exploader’ and ‘Excruciater’. The development of the first nuclear powered submarines by the United States soon led to the abandoning of the project.

Towards the end of their careers, Explorer and Excalibur were used as high speed targets for the nuclear submarine Dreadnought and in anti-submarine exercises with aircraft and surface ships. In 1963 it was decided that it was not worth refitting Explorer and on February 8th 1965 she was handed over at Barrow for breaking up by TW Ward, having been sold for £13,500. Sistership Excalibur was placed on the disposal list in January 1965 and was subsequently sold to Thomas Ward for breaking up and left Barrow under tow on February 5th 1970.

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© Written and researched by Jeremy Olver. First uploaded 21st October 2000. Updated 10th November 2000. Disclaimer.