A proposal to install a more powerful 350 hp Renault engine only partly compensated for a drop in mobility due to the weight increase. It transpired on 13 April 1939 that the intended ARL3 turret, bringing the proposed tank's height to 325 cm, could not be fitted without making the design too wide for rail transport, and further that the weight, now projected at 37.5 metric tonnes, would exceed pontoon limits.
A proposal to install a more powerful 350 hp Renault engine only partially addressed a decline in mobility due to weight increase. It was discovered on April 13, 1939 that the intended ARL3 turret, which would have raised the proposed tank's height to 325 cm, could not be fitted without making the design too wide for rail transport and that the weight, now projected at 37.5 metric tonnes, exceeded pontoon limits.