In 1943, the Japanese adopted the Wartime Standard Merchant Type 1B cargo design. The Type 1Bs used coal-fired steam turbine engines with machinery admidships. They had five deck hatches and double bottoms. 16 were built in 1943 and 1944.
The Wartime Standard Type 1Bs included BICCHU, BINGO, DAIKEI, HANAGAWA, KOKUYO, MIHO, MIMASAKA (BISAKU/MISAKU), MINO, MIYAMA (BISAN), SHIRANESAN, SHIROGANESAN and YAMATAMA (YAMAKYU) MARUS and four others. The 1Bs were discontinued in 1944.
| Builders: | Ishikawajima Jukogyo K.K., Tokyo. Mitsui Bussan K. K.,Tamano. Uraga Dock Co., Ltd., Uraga |
| Years Completed: | 1943-1944. |
| Gross Tonnage: | 4,667-tons |
| Dimensions: | 367.5' x 51'3" x 29'6" |
| Propulsion: | Coal fired, turbine engines, 1-shaft, cruising speed 11 knots, |
| Armament: | Unknown |
