Churchill Infantry Tank

[rickshaw]

The only real problem you will have is with the turret diameter, all of the turrets I mentioned had a wider turret ring which means some minor surgery on your Churchill to make it fit.

Minor?  You'd need to add an adapter ring and rearrange the internal stowage.  It would be easier and cheaper to produce more Centurions.

[rickshaw]

The 17pdr gun was mounted on a widened Churchill hull.  The A43 Black Prince

Jon,

Thanks for sharing those images.  Until now I had no idea that the A43 Black Prince was based on a modified Churchill hull.  The turret appears to have come directly from the early Centurion and it looks quite at home on that hull.

The Black Prince was heavily modified from the Churchill having some 12 inches IIRC spliced into the centre hull to widen it and another amount to lengthen it.  It was seriously underpowered (they didn't up the engine when they added nearly 10 tons to the weight).  The turret's resemblance to the Centurion's is merely because it was designed at approximately the same time.  If anything, it more closely resembles the Comet's turret.

[dy031101]

Speaking of Comet then, if I want a better AP capability than the 6 pounder for the Churchill within the WWII timeframe, could I look at the 77mm HV?

Or would I have had to find an excuse for the British to adopt the US 76mm M1?

[rickshaw]

Speaking of Comet then, if I want a better AP capability than the 6 pounder for the Churchill within the WWII timeframe, could I look at the 77mm HV?

Or would I have had to find an excuse for the British to adopt the US 76mm M1?

The 76mm M1 wasn't a particularly good gun by all accounts.  Its penetration was lower than the 17 Pdr or the 77mm (which was a 17 Pdr with a shorter, squatter breech and a slightly shorter barrel).   It would be a tight squeeze I suspect to put a 77mm into a Churchill turret.  You'd more than likely have to lose the loader.

[dy031101]

The 76mm M1 wasn't a particularly good gun by all accounts.  Its penetration was lower than the 17 Pdr or the 77mm (which was a 17 Pdr with a shorter, squatter breech and a slightly shorter barrel).

But the 76mm M1 can fit into a 3-man turret arrangement, can't it?

Dang, I was hoping that the 77mm HV or the later French 105mm/L44 gun could be used even if the turret has to be replaced with a purpose-designed and built one......  

Would it still be possible?

[rickshaw]

The 76mm M1 wasn't a particularly good gun by all accounts.  Its penetration was lower than the 17 Pdr or the 77mm (which was a 17 Pdr with a shorter, squatter breech and a slightly shorter barrel).

But the 76mm M1 can fit into a 3-man turret arrangement, can't it?

Only if there is space to fit it.  In the 75mm armed Churchill, to allow space for the gun (and more importantly its recoil) and its considerably larger ammunition, I'd suggest you need to remove at least half a crewman.  Its your choice as to which one and which half but I suspect it would be rather cramped in there otherwise.  Remember, its not just a choice of shoe-horning the gun in.  The crew must be able to have room to fight their battle and service the gun.

Dang, I was hoping that the 77mm HV or the later French 105mm/L44 gun could be used even if the turret has to be replaced with a purpose-designed and built one......  

Would it still be possible?

Not really.  See above.  It had been possible, don't you think they'd have tried it?  There is a reason why they decided to go to Black Prince, rather than attempt to upgrade Churchill with a new gun - they simply couldn't do it.  Black Prince proved a failure and Centurion stepped into the ring to take its place just as they decided to get rid of the whole silly artificial Infantry versus Cavalry Tank divide.

[NARSES2]

You are spot on Rickshaw it's really a case of the turret ring being to small to enable easy upgrade, a recurring problem in British tank design right through to the Centurion. I've an old book published by HMSO which gives a great insight to the failures of British design right through the 30's and 40's.

The only way to up gun a Churchill, beyond 75mm is to go down the tank destroyer route which is not something the British did that successfully either.

[dy031101]

Good enough of an explanation, you two.  Thanks. 

[dy031101]

Someone came up with the idea using a QF 25-pounder......

But then I don't know for certain- would a 25-pounder have worked well with the small turret and turret ring of the Churchill tank?

[rickshaw]

Someone came up with the idea using a QF 25-pounder......

But then I don't know for certain- would a 25-pounder have worked well with the small turret and turret ring of the Churchill tank?

Considering that the RAAC was able to put two 25 Pounders on the Sentinel II, and its turret ring was approximately the same size as the Churchills, I don't think they'd have too many problems with the Churchill.



The 25 Pounder however was in relatively short supply throughout the war and fell under the purvey of the RAC, whom were very reluctant to allow mere Tank users to play with their guns.

The problem with the model, as I see it, is that the builder has either developed a new mounting for the gun, with a shortened or perhaps concentric recoil cylinder or he's forgotten that it projected well forward along the bottom of the barrel.  Check out this picture of the Sentinel II (AC3) which mounted a single 25 Pounder and see the massive mantel associated with covering the vulnerable recoil cylinder of the normal mounting which was inverted on this tank:



Interestingly, the prototype Sentinel II with the twin 25 Pounders contributed directly to the development of the Sherman Firefly in the UK.  It proved that a turret ring the size of the Sherman's (which again was approximately the same size) could absorb the recoil of a gun the size of the 17 Pounder.

[dy031101]

Considering that the RAAC was able to put two 25 Pounders on the Sentinel II, and its turret ring was approximately the same size as the Churchills, I don't think they'd have too many problems with the Churchill.

Interestingly, the prototype Sentinel II with the twin 25 Pounders contributed directly to the development of the Sherman Firefly in the UK.  It proved that a turret ring the size of the Sherman's (which again was approximately the same size) could absorb the recoil of a gun the size of the 17 Pounder.

As far as I could find, turret ring sizes of early Sentinel tank, Churchill, and Sherman are 54", 54.25", and 69" respectively......

25-pounder as a choice seems better and better

Nevertheless, did the Sentinel prototype undergo turret ring enlargement when testing the 17 pounder?

[Just call me Ray]

Woah, how did the twin-gun Sentinel work out?

[IanH]

Now a Churchill with a half decent gun like that, would have been VERY usefull

Too right it would have, it's a pity it wasn't thought of at the time!! Or at least the 17 pounder gun!!

Google 'Black Prince Tank' and be surprised...

[dy031101]

Google 'Black Prince Tank' and be surprised...

But the Black Prince needs relatively more-extensive modifications while the 25-pounder might need only a combination of minor internal rearrangements and either a new turret or even just a new mantlet......

[IanH]

Google 'Black Prince Tank' and be surprised...

But the Black Prince needs relatively more-extensive modifications while the 25-pounder might need only a combination of minor internal rearrangements and either a new turret or even just a new mantlet......

I was quoting the Black Prince as a Churchill with a 17 Pounder. 
Whilst it seems logical to fit a 25 Pounder, I can't see the use for it (Anti Armour was a possibility, but only in extreme emergencies).  Granted, at the start of the War, CS tanks filled that niche, and Churchill MkIs had the Hull mounted 3inch, but these were replaced with the SPGs made available later.