First published in the February 2011 AMMS Brisbane newsletter
The Ka Tsu was developed by the Imperial Japanese Navy to give it a ship–to–shore capability similar to that provided by the USA’s LVTs. Introduced in 1944, the 16-tonne vehicle could carry up to 40 troops or four tonnes of cargo, plus a crew of five. Access to the cargo area was via six hatches in the top deck, so it was unable to carry vehicles or large artillery pieces. It was armed with two pedestal–mounted Type 93 13mm ma-chine guns. Propulsion in the water was via two propellers which gave it a top speed of 5 knots.
In preparation for a Pearl Harbour–style raid on American shipping at Majuro atoll, (Operation Yu–Go) 10 Ka Tsus were each fitted with two Type 2 450mm torpedoes. The intention was that the amphibians would be transported to Majuro on five submarines. They would then fight their way across the island into the lagoon, launch their torpedoes at the USN’s ships, and return to the island to wreak havoc with the shore installations. The operation would be supported by IJN ships and aircraft, and Special Naval Landing Forces (ie Japanese Marines). For a variety of reasons, including the unsuitability of the Ka Tsus, the plan was dropped. In the case of the Ka Tsus, it was found during trials that the waterproofing was insufficient for submarine travel, leading to flooding of the engine compartment. They were also thought to be too slow, and too noisy for a surprise raid.
The Ka Tsu was a big vehicle, 10.85 metres long, 3m wide and 3.5m high, which in 1/35 scale is a foot long (31cm). Japanese company Yellow Cat released a resin kit of the Ka Tsu some time ago which isn’t too bad, but as with many of their kits, it benefits from the addition of more detail. I can’t be certain but I think the Ka Tsu used the same 300mm-wide tracks as the Type 2 Ka Mi (see AMMS Bris-bane News November 2010).
Models of the Ka Tsu in 1/72 and 1/350 are also available, with the latter as part of an Aoshima kit of submarine I-41 with two Ka Tsu lashed to the deck.
It is thought that the Type 4 was painted an IJN grey, and as they were built at the Kure naval base, Tamiya IJN (Kure Arsenal) grey would be suitable. It is also thought that some were given a camouflage pattern, probably with a green paint.
Only one of the 49 Type 4s produced has survived, and until a few years ago it was on display as part the amphibious tractor collection at the USMC’s Camp Pendleton, California. I believe it is currently stored in the open air at the Marine Corps Logistics Base at Barstow, California. It does not appear to have been modified to carry torpedoes.
The accompanying photograph show the extant Type Ka Tsu at Camp Pendleton in 1994.