After the 1932 revolution, the Siamese Ministry of Defence started looking for a new kind of weapon, wanting to establish their first Anti-Aircraft Regiment. They were interested in a new Self-Propelled Anti-Aircraft Gun (SPAAG) which was developed by the Vickers Armstrong British company. This was a derivative of the Dragon carrier which was itself a derivative of the successful Vickers series of light tanks, specifically the Mark E.

The Dragon carrier was originally intended to fill the role of an ammunition carrier and tractor for artillery pieces but the large floor area provided by the design allowed for a new open topped higher superstructure. The work was done on a Mark IV Dragon and a single QF 2-pounder Mark II ‘Pom-Pom’ automatic cannon was mounted within this superstructure, creating a flexible weapons platform. Though more than 50 of the Dragon Medium Mark IV tractors were produced, with vehicles exported to India and China, only Siam used this armed open superstructure variant.

Controls:
VTOL= Foward-Backward
Yaw= Left-Right
Pitch and Roll = Turret control
Brake= Brake