I did read the documents in their entirety, actually, the suspension isn’t the only thing that could suggest the redesigned AC IV made it off the drawing board. He describes the Westinghouse Stabiliser in transit to Australia and an experimental set of the new turret bustle mechanisms being created.
As for our mystery tank with the weird suspension - it doesn’t surprise me that the photo shows, as best as I can see, an AC tank with the hotchkiss bogeys removed and large wheels resembling a torsion bar suspension attached to the same vertical volute springs the AC tank’s bogeys were normally fitted to. That seems like a pretty reasonable way of testing a concept like torsion bars without having to modify the tank too much.
I’d also like to point out that the entire point of this rabbithole is to say that the AC IV was redesigned with the application of these new technologies. The AC IV didn’t have torsion bars to begin with, but then they decided to add them along with a slew of other things. The AC IV design was finished, but then it became outdated after they decided to add all these new things. Code basically says that in the first paragraph of “AC MARK IV”
All production drawings for this vehicle with the exception of some stowage items and electrical equipment for the turret traverse gear had been completed, although they will now probably be rendered obsolete by the following recent developments.
My point is that this redesigned AC IV - no it wasn’t fully assembled, but this is war thunder we don’t need it to be - did make it off the drawing board, because the specific components it was intended to have were being made, tested, shipped to Australia from the USA;
Mr. Code has directed that design work necessary to modify Mark IV tank to include the foregoing items be proceeded with; hence the design division is now working on basic layouts for a basketless turret [etc etc] … on receipt of a set of stabiliser equipment which is already on its way from America, we will proceed with the necessary design work to incorporate it.
This redesigned AC IV wasn’t an obscure project or variant or offshoot, it was the AC IV. No, they could not have worked on the torsion bar suspension, they literally said that, but they got cracking on all the other stuff while they were waiting. And yet, somehow, this photo of an AC tank with what looks a lot like a torsion bar suspension with vertical volute springs, for some reason, exists. And, for the record- I don’t know when or where it is from. Who knows, maybe they changed their minds and decided to have a go at this whole “torsion bar” thing anyway. The M4A2E4 was finished testing by the end of August (which they would’ve known about, since that tank’s trial period lines up with their visit to the states). And if not - good thing this redesigned AC IV had more to it than a simple suspension change.
Also, in my opinion, the last paragraph of the page you cited implies that a pilot model AC IV was either built, under construction, or construction was imminent. So, the tank did exist, wholly, not “to a very limited extent”.
I have expressed to Lt. Col. Parker my opinion that the design work involved in this policy is of such a major nature that the construction of a pilot model AC Mark IV built in accordance with the present designs would need to be abandoned […]
Implying that either one was built, or was under construction, or was ready for construction, and would therefore need to be abandoned to account for the redesign.
By the way, if you have sources for the stuff you’ve said about the 64" turret ring, the armour mould (it was the same as the AC III, right? That already had 142 halfway-built? Why would they need a different mould?) and the Scorpion, I’d like to read them, thanks.
