Home - Boats - Submarines - Explorer Class

1955 - 1970: Explorer Class

As early as 1911, Germany was conducting laboratory experiments with closed-cycle propulsion systems that did not breathe air, hoping that it would be possible to build a true submarine, one that was designed to stay submerged, as opposed to a submersible boat. By the start of the Second World War research had gathered momentum and in 1940, following the trials of a prototype hydrogen peroxide-driven submarine - the odd little V80 - a number of experimental boats were built.

In 1946, one such experimental boat, the U-Boat 1407, which had been scuttled at the German collapse, was salvaged and after a long delay commissioned into the Royal Navy as HMS Meteorite. Her recovery led to a British development programme, which resulted in two 1120-ton submarines, Explorer and Excalibur being constructed at Barrow. Built for speed trials only they were purely experimental unarmed submarines. Their high-test hydrogen peroxide engines were basically steam turbines with the steam being supplied from the heat generated by the interaction of high-test hydrogen peroxide (HTP), a catalyst and diesel oil.

HMS Explorer had so many teething troubles that her first captain never took her to sea. However, when she eventually made an appearance, in 1958, she was impressively fast - submerged speeds of 25 knots were achieved - with retractable superstructure fittings aiding the streamlined hull-form.


Provisionally accepted from Vickers in March 1958, HMS Excalibur was built at a cost of 1,142,000 pound. Both Explorer and Excalibur were fitted with the latest submarine escape arrangements including the one-man escape chamber and equipped with the most modem escape breathing apparatus for use by the ship's company in the event of an emergency.

Explorer and Excalibur were, not unnaturally, known as the 'blonde' submarines, because of their peroxide fuel and they served a useful purpose inasmuch as they gave the Royal Navy's anti-submarine forces some valuable practice against fast targets. Their main use, however, was to prove finally that the HTP system was only a stopgap. HTP proved difficult to the point of being dangerous, and there was more than one contemporary report of explosions in the two submarines, and at least one instance when the entire crew was forced to stand on the casing to avoid the noxious fumes, which had suddenly filled the boat. 'I think the best thing we can do with peroxide is to try to get it adopted by potential enemies', said one RN submariner.

Commander Christopher Russell, who captained HMS Explorer - which was known locally as 'Exploder' because of the huge fireballs from her exhausts when starting up - recalls the dangers of working with HTP:

The high-test peroxide was a very volatile substance and was carried in special bags outside the pressure hull. Occasionally there would be a 'whoomph' as one of them exploded. Looking into the engine room, which was unmanned when we were under way, one could see flames dancing along the top of the combustion chamber. We did not look upon her as being dangerous. The crew took the bangs and fires as a matter of course. Fire drill became a very practised affair

The development of the hydrogen peroxide engine did not go well, and a lot of steam went out of the project, in quite a literal sense. When the Americans succeeded in designing a nuclear reactor suitable for fitting in submarines, a new era began and the HTP project was abandoned. Neither Explorer nor her sister Excalibur had much contribution to make in these circumstances, and they were scrapped in 1969/70.



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1954 - 1958: Stickleback Class1956 - 1988: Porpoise Class