Two different prototypes were built and trialled at the start of 1918. The Renault design moved the driver to an elevated position in the centre of the tank with the gun mounted low in the front of the tank. This prototype was found to be overweight and difficult to manouver due to the restricted view of the driver. Exactly how two gunners were expected to service the gun in the cramped forward part of the vehicle has never been explained. The design was rejected.