Churchill Infantry Tank

[dy031101]

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.

The Black Prince is a development of the Churchill that grew larger and wider (the 17-pounder is bulky enough- the M4 Firefly was said by some to be an engineering feat, and it's turret ring is bigger) while the 25-pounder might be able to use the existing Churchill hulls.

[IanH]

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.

The Black Prince is a development of the Churchill that grew larger and wider (the 17-pounder is bulky enough- the M4 Firefly was said by some to be an engineering feat, and it's turret ring is bigger) while the 25-pounder might be able to use the existing Churchill hulls.

On the Firefly, I believe that the 17 Pdr was actually mounted on it's side, to enable it to fit.

[NARSES2]

[On the Firefly, I believe that the 17 Pdr was actually mounted on it's side, to enable it to fit.

It also had the rear bussel added to take the recoil and provide a counterweight, wasn't aware turret ring was increased, infact didn't think that would be possible.

How about the modified 17pdr as fitted to the Comet for a Churchill installation ?

[IanH]

[On the Firefly, I believe that the 17 Pdr was actually mounted on it's side, to enable it to fit.

It also had the rear bussel added to take the recoil and provide a counterweight, wasn't aware turret ring was increased, infact didn't think that would be possible.

How about the modified 17pdr as fitted to the Comet for a Churchill installation ?

It's not, since it involves a major hull redesign, something the Brits didn't want.  If you want inspiration as to what was proposed and laid down in prototype form, drop the Tank Museum in Bovington a line

[dy031101]

How about the modified 17pdr as fitted to the Comet for a Churchill installation ?

Need to work out the turret ring size for the Comet first- with the turret ring size of the Comet as a guideline, I'd imagine that any attempt to enlarge the Churchill turret ring would invariably end up being the Black Prince.

Something that can be retrofitted to existing Churchill hulls might be more practical.

[Sauragnmon]

I have to wonder... they could fit the Sherman Mantlet and gun onto a Churchill (the NA75 variant).  I don't recall the Sherm's mantlet was altered grossly for the Firefly, and the Sherman Turret IIRC was smaller in general size, why not take an NA75 Church, and Field Convert a Field Conversion with a second Field Conversion?

[Mike Wren]

but to fit a 17pdr into a Sherman they had to cut the radio out of the rear bustle of the turret to take the recoil, turn the gun on its side and fiddle about with numerous other things to make it fit & be useable by the crew, it's all very well fitting a bigger gun in there but if you can't actually load it you're in trouble...

[NARSES2]

That's right Mike. You get the feeling that if it could have been done easily it would have been, and the fact that it wasn't done speaks volumes. The more I think of my suggestion of the 77mm in a Churchill the more I realise it wasn't worth it, even if it had fitted. The Comet was coming on stream and the British were finally abandoning the 2 strand approach to tank design and had adopted the "Universal" type, albeit neither the Comet or Centurion were seen as that in the beginning.

Having said that I do have plans for a much bigger gun on a Churchill chasis but that's a secret at the mo 

Chris

[dy031101]

If it can be applied directly to existing Churchill hulls, I can kinda see the value......

They probably did plan to just replace the Churchills with the Black Prince and so didn't bother with existing infantry tanks, but then they ended up producing a vehicle that couldn't be available to beat the war's end or the adoption of the Universsal Tank concept.

[Sauragnmon]

I'm just saying, if the Sherman's mantlet was fitted onto the turret, which would extend the breech's position out of the turret, and the Churchill turret was larger than a Sherman, couldn't it have been done?  It's a somewhat backwards method, so I'm not quite sure if it had even been entertained in truth, but it's just my thoughts, and I'm probably just off my rocker (again).

[IanH]

It's not just the Mantlet that causes the problems - it's the Trunnions (where the Gun balances) - are they in the right position, the right width apart, etc

[buzzbomb]

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.

There are a myriad of reasons why both the 17 pounder and the 25 Pounder options were not followed up for the Churchill.
The links below are fascinating
Firstly the hows and whys of the NA-75 conversion
http://northirishhorse.net/articles/na75/1.html

Even more fascinating are these links to articles by Chris Shillito
http://freespace.virgin.net/chris.shillito/a22new/

The most relevant to this discussion is about the problems of fitting the 95mm Howitzer into a Churchill Mk III turret. The main issue is elevation. The Churchill turrets have a nigh on vertical face with a very small gun aperture. Fine for direct fire 6 pounders but not for a howitzer which needs elevation. The end result was cutting a further enlargement to the gun aperture and since the Churchill's had an internal mantlet, this was a weakness.  The NA-75 got around this by putting he Sherman 75 Mantlet on upside down. The 25 pounder in an indirect role would have the same issues or elevation. As a direct fire AT weapon it was pretty ordinary and would offer no benefit. The 25 Pounder fitting for the Centurion put the gun in facing over the engine deck in a fixed armoured superstructure.

Another thing to bear in mind here was the from 1943 onwards the Brits were pursuing a 17 pounder armed tank but had two projects running the A43 Super Churchill or Black Prince and the A41 "Universal Tank" which was to become the Centurion.
Having said that the idea of using the smaller 77mm gun from the Comet has some merit, but the Comet Turret ring is larger plus the turret is better designed than the standard Churchill turret, that is why the Comet Turret and the Centurion turret (without all the stowage boxes) look similar.  Even the Black Prince turret has that odd angular shape.

As far as models go.. here is one I prepared earlier.. my shot at the Black prince
http://www.modelblokez.org.au/blackprince.html

Love this discussion by the way.

[dy031101]

As a direct fire AT weapon it was pretty ordinary and would offer no benefit.

Maybe, but the QF 75mm has a strong HE firepower yet is no match to late-war German tanks whereas the 6-pounder is pretty much the opposite; would the 25-pounder have been able to match the best of both?

[buzzbomb]

Maybe, but the QF 75mm has a strong HE firepower yet is no match to late-war German tanks whereas the 6-pounder is pretty much the opposite; would the 25-pounder have been able to match the best of both?

For my line of thinking it would depend what you want the tank to do. The Churchill was an Infantry Tank at its initial conception. Having both a 2 Pounder and a 3 inch Howitzer.
The much maligned 2 Pounder was the best AT gun of its time, better than the early 50mm or 37 mm German AT guns and most other guns in that role up until  early 1941ish.  Also the 6 pounder offered much better Armour penetration than the US 75mm did hence the trade off for the NA-75, where these tanks were used as mobile artillery and not as a tank hunting tank.

So if you want the 25 Pounder Churchill to fulfill the role of "infantry tank" i.e support infantry by taking out bunkers, AT guns etc yes the 25 Pounder would do, but if you want to hunt and more to the point..kill tanks.. before they kill you then you need the bestest hard hitting gun you can find and this was slated to be the 17 pounder.  The much larger 32 Pounder AT gun was mounted in the Tortise Heavy Tank and that gun is huge as was the vehicle.

The other thing that needs to be taken into account is ammunition.  The stock 25 pounder used a two part ammunition and 25 Pounder Field gun crew had up to 3 (or more) ammo numbers. For a single man to load a 2 part ammo in a confined tank turret would seriously drop the rate of fire and probably over tax the poor sod doing it. The JagdTiger had the same issues with its two part ammo.. then there is the whole storage issue, bigger ammo = more room = less rounds in the given space.

The more I talk about this the more I get a hankering to build something, because the 25 Pounder Churchill does have some merit. I reckon Andrew Spence on Missing Lynx has probably already done one, he does a lot of what if tanks.

[Weaver]

The other thing that needs to be taken into account is ammunition.  The stock 25 pounder used a two part ammunition and 25 Pounder Field gun crew had up to 3 (or more) ammo numbers. For a single man to load a 2 part ammo in a confined tank turret would seriously drop the rate of fire and probably over tax the poor sod doing it. The JagdTiger had the same issues with its two part ammo.. then there is the whole storage issue, bigger ammo = more room = less rounds in the given space.

Chieftain/Chally loaders seem to cope.....

Okay, it's a bigger turret, but then it's also a heck of a bigger gun too!