[Rupert]

Originally Posted by Þorkell

I've always seen it mentioned that the height of the tank was to fit the engine in it. Also the height of the Sherman is 2.74–2.97m (9 ft 0 in–9 ft 9 in) depending on variant, and as I recall that's measured to the mounted .50 cal machine gun. The Panzer IV (the most numerous German tank) had a height of 2.68m. A Panther is 2.99m, a Tiger is 3m.

It was partly to fit one of the types of engine used, partly to allow for a drive shaft from the engine to the forward mounted transmission without a heavy gearbox on the engine, and partly an inherited feature from the M3 and the M2 before that.

The tall hull is one reason the M4 has a fairly low turret, as a taller one would've increased the height too much.