The Sōkō Sagyō Ki (装甲作業機) was a series of multi-purpose armored engineering vehicles with a bizarre appearance. Designed in 1931, the early models resembled the Type 89 I-Go Medium Tank in the lower half and glacis plate, as it shared some parts with the “model 94” (1934 version) of that tank. The sharp antler-like clearing devices, along with jets of flame shooting from multiple flamethrowers would have made for a fearsome psychological weapon.
It was used as a flamethrower tank in the Battle of Beiping–Tianjin, and may have maintained that capability (despite possible disappointment in performance that is not unusual historically in trials of flamethrower tanks by other countries due to concerns like effective weapon range) even after it was relegated to other duties such as bridge-laying. When U.S. troops captured eight of these tanks in 1945 in the Philippines they classified them as “flamethrower tanks.” This was despite the tanks having been reportedly used mostly for their other abilities since the aforementioned battle in 1937. Regardless of how often it was used as a flamethrower tank, the tanks continued to be used in a variety of roles.
These abilities included:
Barbed wire cutting
Chemical weapons employment
It was perhaps most effective at the last ability, bridgelaying, and two versions of the SS-Ki were specialized for it.
The tank had a maximum armor thickness of 25mm and its armament consisted of 2-3 flamethrowers, as seen in the image above. Also notable in the image is a port for a standard machine gun used in a Type 89 Medium Tank, though it is not clear that it was used as such.
Up until 1943, 119 of these vehicles were built with six variants:
- SS Ki: Main variant
- SS Kou Gata (甲型): Armored engineering vehicle with suspension tracks consisting of four return rollers
- SS Otsu Gata (乙型): Armored bridgelaying vehicle with three return rollers and modified drive sprockets
- SS Hei Gata (丙型): Armored trench digger with identical suspension as the Otsu Gata, with additional armor plates
- SS Tei Gata (丁型): Armored engineering vehicle with identical suspension as the Otsu Gata
- SS Bo Gata (戊型): Armored bridgelaying vehicle based on the design of the SS Ki