“The Battle of the Railway Corps”, 2nd Sino-Japanese War, c. 1940.

“The Battle of the Railway Corps”, 2nd Sino-Japanese War, c. 1940. A Sumida M.2593 (“So-Mo”) convertible armored car in battle.

“The Sumida M.2593 (Type 91) was an armored car produced by the Empire of Japan in the 1930s. It could be converted to operate on both the roadway and railway lines.

“The car was successful in covering great distances during the 1937 invasion of China. They were also used in Manchuria to guard railway lines. The vehicle could be coupled together and operate on the rails like ‘rolling stock’. This led them to be used in joint operations with trains and were also used for reconnaissance by the army.

“Designed by the Sumiya firm, beginning in 1933 the M.2593 was produced at the Ishikawajima Motor Works. A defining feature of this vehicle is that its six road wheels could be exchanged for flanged railway wheels. When not in use, the tires would be secured to the sides of the hull.

“The vehicle had four built-in jacks for use when the wheels were changed. It would take ten to twenty minutes to change the wheels. The front and rear sets of wheels could even be adjusted to various rail gauges. The car was capable of 25 mph (40 km/h) on surface roads; traveling at higher speeds on rails, up to 37 mph (60 km/h).

“The M.2593 carried no fixed weapons. Its crew carried rifles which could be fired from gun portals or operate a machine gun from within a rotating turret on top of the vehicle.”

– Wikipedia