I worked on these vehickles more most of the 7 years I spent in the army. While in germany I was required to have a top secret security clearance to even work on them. I have seen the 45mph speed quoted so many times that I have to say that that was the officially published top speed for a nicelly straight flat paved or unpaved road while in reallity these little things easily kept up with convoys going over 50 mph. Also the main danger inside the turret was to the loader many of whom suffered arm fractures when the main guns air evacuation system blew its internal parts into the turret(it was on the left side of the breech) due to a design flaw that allowed the rounds full pressure when fired to slowly erode that mounting untill the full force of the round igniting blow the internal parts into the turret where the usually hit the loader first. I once deadlined a hole company of 551s for this after inspecting the stste of erosion inside this mounting tube.