The F B was an Imperial Japanese Army (IJA) military transport/personnel carrier used for crossing difficult swampy terrain.

A total of 146 F B units were built, making it the most numerous model produced of this type of vehicle by the Japanese Army.

The F B swamp vehicle was a military transport/personnel carrier of the Imperial Japanese Army (IJA), which was developed and used for crossing swampy terrain.

[1][2] The S B swamp vehicle was the first prototype design built by the IJA for use as a military transport/personnel carrier for crossing swampy terrain and waterways.

Built in 1933, like the subsequent F B vehicle it had rubber floats attached to its track links to prevent it from sinking in the mire.