Hmmmm. Is this tank fitted with a 1 man turret? Otherwise, I think you need to either increase the size of the crew or suppress the front hull machinegun, because the driver's not going to have time to operate a flexible MG.
Heh, even if I did, that doesn't mean it's perfect. But, looking at the file, it does have a 3 man crew (commander, gunner, driver), and no hull machinegun. It has a single turret MG with 2000 rounds.
I changed the crew to 4 men. I don't see any reason why there wouldn't be enough room considering the AT-32 and 34 designs have 4 man crews and they are smaller tanks.
How tankbuilder would handle another crewmember on the otherhand.....
The 3 man crew of the AT-31 makes sence given its narrow glasis and possitioning of the driver.
Tanksharp would just add some weight, there's plenty of space in the hull. The extra weight would increase the ground pressure a little and slow it a little, but not much in either case. I'll tweak it in the morning.