The special Type 4 Launch Ka-Tsu (特四式内火艇 カツ, toku-yon-shiki uchibitei Ka-Tsu) was a Japanese amphibious landing craft of World War II. The first prototype was completed in late 1943 and trials were conducted off Kure in March 1944.

Type 4 Ka-Tsu
A Ka-Tsu on display
Place of originEmpire of Japan
Production history
Designed1942–1943
No. built49
Specifications
Mass16 tons[1]
Length11 m
Width4 m
Height2.25 m
Crew5

Armor10 mm[1]
Main
armament
2x torpedoes[2]
Secondary
armament
2x 13 mm machine gun[1]
EngineGasoline engine in a water-tight pressure box
62 HP
Power/weight3 HP/1 ton
Suspension-
Operational
range
-
Maximum speed (sea) 5 knots

History

edit

Japan's combat experience in the Solomon Islands in 1942 which revealed the difficulty of resupplying Japanese forces in such situations prompted the IJN to commence an amphibious tractor program in 1943, as the Ka-Tsu,[3] which was designed by Commander Hori Motoyoshi of the Kure Naval Yard.

Design

edit
 
Type 4 Ka-Tsu with machine guns mounted
 
Rear-side angle view of Type 4 Ka-Tsu

The Ka-Tsu's primary purpose was to transport cargo and/or troops ashore.[2] It had light armored shielding with a maximum of 10 mm.[1] Its engine compartment and electric final drives were hermetically sealed, as it was intended to be launched from a submarine.[3] The twin drive propeller shafts were designed to retract "into their ducts" once the vehicle reached the beach.[2]

The first prototype was completed in late 1943 and trials were conducted off Kure in March 1944.[3] By the time development had been completed, it was proposed that the Ka-Tsu be used to attack US battleships anchored in atolls (such as Ulithi), which could not readily be attacked using conventional means. It was proposed that a Ka-Tsu armed with a pair of torpedoes be dropped off by submarine away from the atoll, propel itself to the outer reef using its tracks, and then enter the lagoon on the inside of the reef. Tests were successfully carried out with a modified Ka-Tsu carrying two torpedoes on its deck, but the war ended before any such mission could be mounted and the Ka-Tsu deployed in combat.[3] A total of 49 units were produced.[1]

See also

edit

Notes

edit

References

edit
  • Tomczyk, Andrzej (2003). Japanese Armor Vol. 3. AJ Press. ISBN 978-8372371287.
  • Zaloga, Steven J. (2007). Japanese Tanks 1939–45. Osprey Publishing. ISBN 978-1-8460-3091-8.
edit