No.101-class landing ship

The No.101-class landing ships (第百一号型輸送艦,) were a class of amphibious assault ships of the Imperial Japanese Navy (IJN) and Imperial Japanese Army (IJA), serving during and after World War II. The No.101 class ships were powered by diesel engines, while the similar No.103-class landing ships (第百三号型輸送艦,) were powered by a steam turbine engine. The IJN called them 2nd class transporter (二等輸送艦,). The No.103 class included the IJA's SB craft (SB艇,) variant. This article handles them collectively.

Background

 * In June 1943, after its defeat in the Guadalcanal Campaign, the IJN realized it needed high-speed military transport vessels, and designed two classes of ship in response. One (the No.1-class landing ship) was to be the 1,500-ton mothership of the Daihatsu-class landing craft and Kō-hyōteki-class submarines, the other was to be a 900-ton amphibious assault ship, the No.101 class.
 * The IJA already had an amphibious assault ship, the SS-class landing ship. However, the SS craft were not suitable for mass-production, leading to IJA support for the new amphibious assault ships.
 * The IJN and IJA therefore cooperated on the production of the new amphibious assault ships with the IJN providing design and shipyards while the IJA offered mineral resources.

Design

 * The IJN had obtained information regarding Operation Torch from Germany, including some photographs and sketches of the LCT Mk.V.
 * In August 1943, the Navy Technical Department (Kampon) studied these and finished a basic design. It was a scaled-up model of the LCT.
 * In September 1943, the Kampon entrusted the detailed design to the Kure Naval Arsenal. The Kure Naval Arsenal completed this within two months, and the No.101 was laid down in November 1943.

Construction

 * The Kampon designed a new turbine engine for this class. However, it was not ready in time for the first 6 vessels. The Kampon therefore installed the wartime standard diesel engine in the first 6 vessels. The IJN called them No.101 class or SB (D). Turbine engines were available in time for the remaining production, which the IJN designated the No.103 class or SB (T). Completed vessels were split between the IJN and IJA.
 * The IJA received 32 vessels from the No.103 class, however the IJA had difficulties with the steam turbines engine and returned 10 vessels to the IJN.
 * Several No.103 and SB class vessels were converted to use coal-fired boilers in January 1945. Detailed construction records do not exist, but photographic evidence confirms the conversion of No.147, SB No.101 and SB No.108 with the presence of a tall funnel.

Navy service

 * Most of the Navy vessels took part in the Battle of Leyte, where 18 of them were lost. Most, however, succeeded in landing their tanks and troops.
 * Only 9 vessels survived the war.

Army service

 * As of 2009 a detailed record of the vessels in the Army service is not known to exist in Japan.
 * The armaments were not standardized.
 * The IJA let ten SB craft participate in the Philippines Campaign. Their actions were limited to the Luzon northern coast, Taiwan and Ryukyu Islands. The IJA lost only one SB craft.
 * After the Philippines Campaign, the SB craft were used only in the Japanese mainland peripheral sea area.