Aussie Sentinel tanks

[Roger Lucy]

Originally Posted by easo

the Sentinals were a technical advancement for their time as they were the first production tank to use both cast hull and turret together.

I think the Ram may have beaten-out the Sentinel as the first production tank with a cast turret and hull. The first Ram prototype was completed on 30 June 1941 and they were in full production by the end of the year. Actually the pre-war French Hotchkiss and Souma tanks had cast hulls and turrets, but their hulls were not cast in one piece.

Did the later Sentinels (AC3 and AC4) with the 25 pounder and 17-pounder guns use the same 54-inch turret ring as the AC1. A 60-inch ring was considered necessary for the Ram's 6-pounder and a three-man crew (although 40 were up-gunned to 75mm).
Roger

[Mike Cecil]

I think what Easo meant to say was that the Sentinel was the first tank to utilise a single casting for the entire hull.

The 'AC4' was, of course, a 'drawing board' tank: it was not actually built. The images that purport to show the AC4 are actually an E series (I think E-3?) test bed hull with a turret casting mounting a 17pdr: it was a concept mock-up only. Note, in the image, the 'stub' of the hull MG mount in the centre front of the hull: a feature of the AC1 deleted in the AC3, and would have been deleted in the AC4 as well, if it had reached prototype stage.

Not sure what the projected turret ring diameter was: will have to check.

Mike C

[Ryan]

According to the link I earlier posted (page 1):

AC3 test rig and production tank had a 54inch ring, same as AC1.
AC4 test rig had a 64inch ring.
AC4 production tanks were to have a 70inch ring.