midget submarines were employed by the Italians, who had pioneered their use during the
First World War, and by the British, Germans, and Japanese, with varying degrees of success. They were mostly used to attack warships in defended harbours which conventional submarines had little chance of penetrating. The crews of British midgets used
limpet mines, Axis ones mostly
torpedoes.
The British operated three types: variants of the one-man Welman, a cross between a midget submarine and a
human torpedo; the 15.5 m. (51 ft.), 35-ton, four-man X-craft; and the XE-craft, a later development of the X-craft, which were employed in the Far East where their crews cut Japanese communication cables and damaged a cruiser.
SOE's Welman was a failure, but six X-craft altered the balance of
sea power in northern waters when they attacked, and badly damaged, the German battleship
Tirpitz in September 1943. In April and September 1944 others attacked a floating dock in Norway—which an earlier Welman operation had failed to destroy—and two more were used by
Combined Operations Pilotage Parties to survey the Normandy beaches and then helped guide in the invasion forces in June 1944 (see
OVERLORD).
The Germans also operated three types: the 9 m. (29.5 ft.), 6.5-ton Biber (beaver), in which the crewman was apt to be asphyxiated by carbon monoxide from its petrol engine; the 10 m. (34.4 ft.), 11-ton Molch (newt), which attacked Allied shipping off the Normandy beaches during OVERLORD and elsewhere without achieving much; and the more successful diesel-engined two-man 11.9 m. (39 ft.), 14.7-ton Seehund (seal), which sank a number of Allied ships.
In 1941 the Japanese Navy had more than 40 two-man, 24 m. (78.5 ft.), 46-ton Ko-gata (Type A) midget submarines. Five were used, and lost, in the attack on
Pearl Harbor, after being carried there by fleet submarines, and they attacked British warships at Diégo Suarez, Madagascar, in May 1942, damaging a battleship,
Ramillies, and sinking a tanker. Type As were also used to attack shipping in
Sydney harbour and at
Guadalcanal. The three-man 25 m. (82 ft.), 50-ton Hei-gata (Type C) was employed with Type As during the
Philippines campaigns and elsewhere but with little success. The Japanese also developed two types of suicide midget submarines: the 17 m. (56 ft.), 19-ton two-man Kairyu (Sea Dragon) and the larger, faster 26.2 m. (86 ft.), 60-ton, two- or five-man Koryu (Scaly Dragon) which had explosive charges in the bows or could carry torpedoes.
The Italians had several prototypes but the only operational ones were the four-man CBs which were used in the
Black Sea with some success during the Axis blockade of
Sevastopol. A plan to attack shipping in New York harbour with another type of midget submarine was thwarted by the surrender of Italy in September 1943. See also
Tenth Light Flotilla,
Germany, 6(e),
frogmen, and
human torpedoes.
Bibliography
O'Neill, R. , Suicide Squads (London, 1981).