T.1-class Fast Transports

(Fast Transport T. 9 under construction at Kure)

In 1942 and 1943 during the fighting on Guadalcanal and the Solomons, large, slow transports and destroyers converted to high-speed transports were unable to carry and land sufficient quantities of troop and supplies needed to sustain protracted combat operations in the face of American air superiority.

In April 1943, the IJN General Staff submitted a requirement to the IJN Technical Department for new, purpose-built fast amphibious assault transports capable of carrying and rapidly landing troops, cargo, Daihatsu landing craft or Type 2 Ka-Mi amphibious tanks.

The IJN Technical Department responded with designs for the new T.1-class fast naval transports that could be constructed using mass production techniques such as pre-fabricated parts and electric welding. The T.1-class transports were based on Matsu-class destroyer hulls with one set of engines removed to make space for troops and cargo. At 22 knots, the resulting 1,500-ton vessel was quite fast for an assault transport. The T.1-class design featured a distinctive stern equipped with rollers and sloped down to the waterline. The T.1-class was capable of rapidly launching landing craft. One 13- ton and four 5-ton derricks were fitted to move cargo.

Later, the design was amended to permit the T.1-class to carry 46-ton Type A “Ko-Hyoteki” and 59.6-ton Type D “Koryu” midget submarines and kaiten human torpedoes and Shinyo explosive motorboats (EMB). The class were equipped with AA guns, depth charges, radar and sonar. During the war, the heavily-armed T.1-class fast transports were also used as minelayers and as escorts.

In October, 1943, 46 units of the T.1-class were ordered. Fifteen were built at Kure Naval Arsenal and six at Mitsubishi Heavy Industries Most of Kure's vessels were completed within 80 days after their keels were laid. T.22 was launched on 25 April 1945, but work was stopped on 23 June 1945 when 80~90 percent complete and scrapped in June 1948. In May 1945, the remaining 24 T.1-class units were canceled.

This page will cover all 21 units of the T.1-class. The war-time careers of the T.1a are generally relatively shorter than many other warship types covered in our TROMs. In at least one case, the T.1-class unit survived for less than a month after completion.

Builders and
Years Completed:
Kure Naval Arsenal and Mitsubishi Heavy Industries, Yokosuka
Displacement: 1,500-tons standard.
Dimensions: 315' (LOA) x 33.1' x 11.75'
Propulsion: 1 × Kampon geared turbine, 2 × Kampon water tube boilers, single shaft, 9,500 shp, speed 22 knots
Armament: 1 x twin 12.7 cm/40 Type 89 dual purpose AA gun; 3 x triple 25 mm/60 Type 96 AA machine cannons; 1 x twin, 25 mm/60 Type 96 AA machine cannon; 4 x single (15 x 1 from Sep '44) 25 mm/60 Type 96 AA machine cannons; 5 x single 13 mm/76 Type 93 machine guns (Sep '44); 18 depth charges (42 from May '44); 4 DCT (from May '44)
Equipment: Radar: 1 x Type 22; 1 x Type 13 (Feb '45)
Sonar: 1 x Type 93 sonar, 1 to 4 x Type 93 hydrophones
Cargo Capacity: 4 × Daihatsu and 260 tons freight or 7 × Type 2 Ka-Mi tanks and 220 tons freight or 2 × Ko-hyouteki midget submarines and 184 tons freight or 6 × Kaiten human torpedoes or Kairyu midget submarines and 243 tons freight