AC1 is 54", AC3 is 54" and easiest way to know this is because the turret ring part numbers are the same for the AC1, the AC3, and the Rhino, the AC4 design started with a 64" as the AC hull "box" is 5'7.5" wide less 45mm off each side leaving 64" internal clearance, to give more elbow room and space higher up in the basket this was then increased to 70" but the project was cancelled before anything that large was made in steel.
Sir John Valentine Carden Survives. Part 2.
- Thread starter allanpcameron
- Start date
The early cold war heavies were all gotten rid of as soon as the the MBT's had a gun that was able to do their job. The Conqueror wasn't adopted because of it's armour, it was the gun. As soon as the L7 105mm showed up armies started to get rid of the heavy tanks as the MBT's were more than enough.
Unless the Churchill goes down a full on Black Prince style redesign but also gets a Meteor it will be hard pressed to show what it can do. With the HV main gun the Victor can kill things the Churchill cant with a 6pdr as remember the ROQF 75mm isn't a thing yet ITTL. That means the HE lobbing is being looked at being filled with the 95mm which is still being developed.
So the Churchill as it stands has a very good hole puncher of a gun (the 6pdr was the best AT gun of the war) a decent enough but hull mounted HE thrower and armour comparable to the Victor with less speed. What exactly does it offer at present? Yes there could be a major redesign to increase the armour, fit a better gun and improve the speed but realistically your only going to be able to do two of those things and keep one roughly the same. The simple fact is that any development of the Churchill will take time. In OTL the development of the Black prince took roughly 18 to 24 months so if work started on an improved Churchill so if we assume that work started on the first of January 1942 then at best it will be June 1943 at the earliest before an improved enough to be considered Churchill could be ready. By that time the Venom will be right around the corner as well and will have a similar gun (the Venom will in all likelihood start out with the 17pdr at least initially), similar armour and probably notably better speed.
ITTL the HV gun will do the job in the short term. The 17pdr is coming along to do the job in the medium term in some capacity and the 32pdr or some other gun will come along in the longer term. All will be more than good enough to deal with the likely heavy tank threats rendering the heavy tanks surplus to requirements. Honestly I think the plan for a 32pdr type gun is overkill for the war. The 17pdr will be more than good enough until 1945 and has the benefit of easier logistics and longer production times to boost numbers.
Well you look at it and the Valiant has the 6-pounder (57mm)/75mm, the Victor has the 75mm HV (76.2mm), so the 3.7"/95mm is only a fraction over that next step. Too much gun for WW2? Possibly. But the Venom likely won't show up until at least the middle of 1944 when the war is already in its final stretch. And that's assuming they can get all the parts on time. Any technical difficulties will likely push it to late '44 or early '45, when it's all over bar the shouting.
i would argue when the venom will be available at the earliest, mid 1944.
ya right, in the beginning i assume that ITTL Churchill hull was more widen than OTL, due to butterfly, meaning that it can equipped a 17 pounder, and can be more easily fitted with a Bigger and better engine, so i imagine a 1943 service date. But after the converstation with @MattII i am now in agreement that the ITTL Churchill hull were likely not widened compare to OTL (due to vauxhall not being as good as Carden?).
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Derek Pullem
Donor
Relying on wiki but it looks like a prototype with a larger turret ring (64") was made - AC1 E1 to test out the 17 pdr?
That is the commonly accepted story, and I've been told that before. I am however somewhat skeptical as the E1 hull appears unaltered. I suspect where they wrote "64 inch turret" it was being used more as an identifier to differentiate it from the then-being-worked-on 70 inch turret, rather than as an actual 64 inch measurement. I don't think a 64" ring would actually fit, side to side is fine but with the raised driver's and gunner's hood and the engine deck air vents mean you'd probably run out of space fore and aft. I could be wrong, but it is the best fit for the available information in my opinion.
This is an important point. Garden was an expert tank designer, he knew this, and so did the people buying tanks. If he looked at a specification and said “yeah, I’m going to bend the rules here and ignore them there”, there was a bloody good chance he would get away with it. The fact that he did it in the past and it worked out for the Army (Pompom Matilda) only makes this more likely.
Vauxhall have the opposite problem, in that they, with their lack of experience, will not be as inclined to flout the specifications as they’ll assume that the people who wrote them know better than they do.
That’s the Sabre aircraft engine. Different H-24.here some article about the H-24
Napier H-24 Sabre Aircraft Engine
The Naiper Sabre was the last H engine designed by Frank Halford. From a troubled start, the complex Sabre ultimately produced more power for its displacement than any other WWII aircraft engine.oldmachinepress.com
Documents would rather indicate that Churchill was among the better hill climbers, but not all that exceptionnal, slightly better than a Sherman. In general it does neither very good nor evry bad in most terrain, but obviously it can do better than most competitors in some terrain, and worse elsewhere. Regardless I'm pretty much convinced its hill climbing properties are down to the tracks (though the Soviets said it had poor traction, so maybe not) and the transmission/engine combination giving adequate torque.
The suspension itself is very mediocre so isn't responsible for good mobility, or rather, the poor suspension is sufficient at the low speeds of Churchill, but prevents use of higher speeds on road and off-road. This is also why a Meteor Black Prince wouldn't have been able to exploit the full potential of the powerplant.
It would fit, the engine change planned for AC4 only allowed 70" but the previous hulls could still go as far as 64".
Honestly, I have some doubts now that Carden really was the best candidate for the tank designs featured in the timeline. His main contributions OTL were mostly very small, simplistic and light tanks after the Vickers Mk III and Independent lost favor (not even sure he specifically worked on them). Not exactly the kind of man who exploited the maximum weight and size limitations. And it's not like heavier tanks were not required in Britain or abroad, see the A7 which started development before Carden's death but had no Vickers competitor.
@one13 I got the info on the Ricardo H types from Andrew Hills (writer of Tanks of TOG), I can give more details but he is the one who had the archives. Frankly quite unfortunate that for some reason we have extremely few primary documents on British tank engines (even Meteor and Liberty) shared on the Internet, people already dug up and shared way more info on American Sherman engines. Guess people have to go to Kew or Bovington.
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Except the Merritt-Brown gearbox. Triple-differential gives a variable speed that allows greater hill-climbing capability than any double-differential system.
He was rather involved in the Vickers 6-ton. As to a competitor for the A7, I'd like to see proof that the specification was ever farmed around, before I'd accept that Carden wasn't up to the job.
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if ITTL you want a better infantry support tank that can climb mountains like a goat there is always the OTL solution from the Italian campaign, which was the Churchill N.A. which was fitted with the Sherman's 75mm gun
If a field workshop is able to modify turrets and even flip the gun upside down to get it to work then I certain the British industry can come up with something similar.
It all depends why you want the25lb on a tank. There are better guns for punching holes in enemy tanks and for close support the American 75mm or the OTL 95mm howitzer/gun from the Centaur are probably good enough.
In tank use the 25lb would probably require fixed ammunition, rather than the artilleries existing separate type then in production, is that added logistics complication really needed ITTL?
If a field workshop is able to modify turrets and even flip the gun upside down to get it to work then I certain the British industry can come up with something similar.
It all depends why you want the25lb on a tank. There are better guns for punching holes in enemy tanks and for close support the American 75mm or the OTL 95mm howitzer/gun from the Centaur are probably good enough.
In tank use the 25lb would probably require fixed ammunition, rather than the artilleries existing separate type then in production, is that added logistics complication really needed ITTL?
I’m curious how the exercise will go especially since they seem to have worked out how unsecure British Comms are and how poor comms discipline is I can see every Intel officer having a seizure when it gets fed back to them.
Though with the way things are going I have to wonder if the US will ask foe or buy some Victors for their own testing.
Though with the way things are going I have to wonder if the US will ask foe or buy some Victors for their own testing.
Vickers will probably be happy to deliver a few, if they're allowed to send some engineers on to report back. It ought to be rather interesting actually. I mean, the Victor has a 75mm HV gun, but only a 66" turret ring, so it ought to give them some clues on how to design a turret for the Sherman that's capable of taking the 76mm gun, rather earlier than OTL.
MB Triple diff doesn't help climbing, it helps steering. Only technical difference in the former regard between MB and double diff is that it turns steering shaft even in a straight line, which slows down the sprocket and increases torque a bit, but it's geared with that taken into account. Final drive on MB is slightly longer to accomodate the higher torque so at the end nothing changes. Not that the better steering wasn't useful in other areas, though there are caveats vs double diff.
He was, but again the 6-ton was not an ambitious tank and reused ideas from the Carden-Loyd, so not exactly a design intended for high weight growth. Carden is known to have worked on A9. A11 was mostly headed by his right-hand man Leslie Little, who helped on most Carden-Loyd projects in general.
A6/Vickers Mk III was not developped under Carden, at least not until it was already a prototype as Carden was only brought in in 1928-1929, and his main contribution was testing a suspension for it which was still not sufficient. Correction, Vickers did design a competitor for the A7, the A8 from 1933 with Wilson gearbox and twin RR Phantom IIs (similar to A7 concept), but it never went anywhere and was cancelled in 37. No guarantee Carden worked on this one specifically.
The last tank we know for sure Carden worked on was the A9, and this started in 34 so hard to say how involved he was in A8. But overall he seemed to be more involved in "light stuff". Not that he couldn't contribute to heavier vehicles, the A9 was still a big upscale from 6-ton, but still, not super ambitious designs even in an era where the UK was developping "heavy" designs in parallel.
There are sources that would disagree with that claim.
There wasn't much of a market for big tanks in general in the late 20s and early 30s, and Carden was being employed by Vickers, so he was almost certainly employed in projects that might actually keep Vickers solvent.
Carden was only brought in that late because Vickers bought his Company in 1928, therefore it was impossible for him to have been involved earlier.
Carden died OTL in 1935, so how much work he could have put in is up for debate.
Given that Britain didn't see spending millions on arms as a way to beat the depression, I have my doubts how much money was available for development.
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There's nothing particularly wrong with the idea of a 25pdr as a tank gun. Compared, like with like, against the 75mm, the 25pdr will actually go through more armour, where the 75mm has an advantage is that it was being used as a tank gun and so a HVAP round was made for it, presumably such a projectile type for the 25pdr would once again go through more. As shown by the Australian tank programme, the two part ammunition is serviceable they were happy with the rate of fire along with everything else and in that case they were of the opinion that fixed ammunition was not desirable.
Yeah your probably right. Ideally I'd want a smaller calibre so 90mm at most but Britain isn't really making anything in that calibre outside of the 25pdr. Actually thinking about it. If Britain has the ability to make a 3.45" gun barrel long enough then using the 25pdr as the base of the next gen tank gun would be my ideal I think.
The HE shell will be very good, lots of other types of ammo and with a bigger cartridge case the AP rounds could get to some pretty good velocities. I actually quite like that idea as the gun wouldn't be much less powerful than a 32 pdr but with lighter ammo. Even if the same cartridge is used as the 32pdr just knocked down more your saving at least 7lbs of weight and getting some ferocious muzzle velocities.
As it stands though I think the Venom will be designed for rather than with whatever the next gun ends up being. The 17pdr will probably be fitted initially.
Back to the Churchill for a second. I just checked back and there was a post all but confirming that no more Churchill's will be ordered.
As it stands the Churchill still has the 2pdr gun with only plans to try and fit a 6pdr. Once that is done you end up with a slower but slightly heavier armed Valiant II rather than a Victor rival. It would take a new engine as well as a new gun to truly rival the Victor so I don't see how it carries on.
As it stands the Churchill still has the 2pdr gun with only plans to try and fit a 6pdr. Once that is done you end up with a slower but slightly heavier armed Valiant II rather than a Victor rival. It would take a new engine as well as a new gun to truly rival the Victor so I don't see how it carries on.
Mm, I think the engine will pose enough problems that the gun will be ready first.
Maybe but I seem to recall that there were discussions about the engine required for the venom being had with Ricardo in 1941. That means that he has 2 years at minimum to get something ready whereas I can't remember any indication that any work has started on a new gun, only talks about what is required.
The Meteor is still around as an interim engine and while using an interim engine is far from ideal it was used OTL to power the 50 ton Centurion so could at a push do the job.
2 years is a good rough estimate on how long it will take to develop the gun based on other British AT guns designed historically during the war.
That means that early 1944 at the earliest is the soonest you could expect any gun to be ready let alone able to be fitted into a tank.