SS-class landing ship

The SS-class landing ship (SS艇 or 機動艇) was a class of amphibious assault ships of the Imperial Japanese Army which served during World War II. The SS meaning are Sensha-Small.

Background
October 1938, the IJA employed the Shinshū Maru during their successful amphibious operations at Bias Bay. However, a considerable amount of time was needed to complete the operation owing to the low speed of the landing craft, which resulted in considerable damage to the vessels involved.

The IJA employed the principles of speed and minimum damage to their amphibious warfare operations.

In 1939-1940, the IJA repeated an experiment with Gorō Maru (300 tons gross) and Yorihime Maru (526 tons gross) and after analysing the experiment data placed an order for the prototype Kōryū (later SS No.1).
 * The IJN was interested in the second prototype Banryū (later SS No.2). The IJN placed an order for 16 ships. However, thereafter they adopted the No.101-class and the order was cancelled.

SS No.1

 * Kōryū / SS No. 1 (蛟龍, 機動第一号艇)

SS No.2

 * Banryū / SS No. 2 (蟠龍, 機動第二号艇)

SS No.3 class

 * Kairyū / SS No.3 (海龍, 機動第三号艇)
 * SS No.4, Sunk in action on 12 October 1944
 * SS No.5, Sunk in action on 30 November 1944
 * SS No.6, Sunk in action on 7 December 1944
 * SS No.7
 * SS No.8, Sunk in action on 19 November 1944
 * SS No.9, Sunk in action on 6 December 1944
 * SS No.10, went missing on the night of December 1-2, and lost with all hands after departing Palompon, Leyte. USS Conway (DD-507), USS Cony (DD-508), USS Eaton (DD-510), and USS Sigourney (DD-643), all did report sinking an enemy vessel in the area the convoy would have been in.
 * SS No.11
 * SS No.12, Sunk in action on 21 January 1945
 * SS No.13
 * SS No.14, Sunk in action on 22 May 1945
 * SS No.15
 * SS No.16
 * SS No.17
 * SS No.18
 * SS No.19
 * SS No.20
 * SS No.21
 * SS No.22, Sunk in action on 10 August 1945