Author Topic: Churchill Tank  (Read 88634 times)

Offline raafif

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Re: Churchill Tank
« Reply #125 on: January 04, 2015, 01:43:57 PM »
Since I came across people during this past week talking about how Yugoslavia was able to keep their T-34-85 somewhat useful during the Cold War with domestically-developed HEAT ammunition, I couldn't help to think of a Churchill with 25-pounder tank howitzer again...... this time in Yugoslav colours even though they used neither, IIRC......

I'll have to read the book again but I'm fairly sure Tito wanted Churchill tanks but it was recognized that the war would probably be over before the Yugos could be trained to maintain them & put the necessary workshops & parts-supplies in place.  Tito's Soviet leanings precluded post-WW2 supplies of anything from the UK.  Smaller tanks were more suited to the hilly terrain too.

Offline Volkodav

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Re: Churchill Tank
« Reply #126 on: January 04, 2015, 03:32:49 PM »
Following experience in the Pacific Australia ordered the Churchill, predominantly CS and flamethrower versions, to supplement and replace the Matildas that the RAAC was using in theatre in preference to the M-3 Mediums in-service.  The Churchill was actually ordered after evaluation of a number of types in Australia, including the Sherman and Cromwell.

My gut feeling is if the US had developed the Churchill for the UK they would have been able to widen the hull and fit a larger turret quite easily.

Offline ChernayaAkula

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Re: Churchill Tank
« Reply #127 on: January 05, 2015, 05:41:18 AM »
<...>  Tito's Soviet leanings precluded post-WW2 supplies of anything from the UK.  <...>


Did they?  ;)



If you look at Yugoslav history, there's a very good possibility of such a whif scenario ( Yugoslav Churchills) actually coming to fruition.
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It was during that time that Yugoslavia received Western tanks (M18, M36 and M47) and aircraft, jets (T-33, F-84G, F-86D and Canadair Sabres) as well as props (F-47 Thunderbolts and D.H. Mosquitoes).
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Moritz

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Offline Volkodav

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Re: Churchill Tank
« Reply #128 on: January 05, 2015, 06:12:02 PM »
Oh and the small matter or the Nenes and Derwents the UK exported to the USSR, making the MIG 15, and other advanced types whose development was held up by the lack of suitable engines, possible.

Offline Weaver

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Re: Churchill Tank
« Reply #129 on: January 05, 2015, 09:41:07 PM »
Britain sent two Gnat F.1s to Yugoslavia for evaluation as late as 1958 and if they'd been selected, there seems little doubt a production order would have followed, possbily even with licenced production.

It's worth remembering that all Yugoslavia's post-war jets (Galeb, Jastreb, Orao, Super Galeb) were powered by licence-built RR Vipers and they also built Gazelles and Sikorsky S-55s under licence: http://www.airliners.net/photo/Yugoslavia---Air/Westland-WS-55-2-Whirlwind/1335527/L/&sid=b84dfc9613be7729df65a9e177ee2194
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Offline Volkodav

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Re: Churchill Tank
« Reply #130 on: January 07, 2015, 12:00:06 AM »
Rickshaw, I am reading a very good e-book at the moment called "Fallen Sentinel" that covers the history of Australia's WWII tank program, covering the military, engineering, industrial, political and strategic factors.  It's one of the new series of thoroughly and impartially researched books on Australian military history using cabinet papers and original source documents.

Only about a third through at the moment, really enjoying it and the number of facts I never realised relating to timings and industrial capacity.  I was interested to read that, although initially supporting the program, the US later wanted Australia to drop the indigenous design and build M-4s instead threatening to withhold promised machine tools to force Australia to comply.

Really looking forward to getting onto the tropical tank trials and the selection of the Churchill over the Sherman and Cromwell.  I have read some pieces on that previously but get the feeling this book will be much more informative.

Offline dy031101

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Re: Churchill Tank
« Reply #131 on: January 07, 2015, 01:43:01 AM »
Despite this, want to know what one of my favorite tank models on Beyond the Sprues is? Claymore's Big Mac.

I think it's completely impractical and a combination Churchill/King Tiger sounds like an unholy spawn that would be lucky to make it out of the marshalling yard, let alone drive all around sub-Saharan Africa, but MAN it looks right!


Damn, and I wanted to (and still kind of do) combine a M103 or Conqueror turret with the Black Prince!

(Yes, I also toyed with the idea with Centurion turret, but since Black Prince is nowhere near as mobile as a Centurion, I figured it could use some superior firepower......)
« Last Edit: January 07, 2015, 02:00:16 AM by dy031101 »
Forget about his bow and arrows- why wait until that sparrow has done his deed when I can just bury him right now 'cause I'm sick and tired of hearing why he wants to have his way with the cock robin!?

Offline GTX_Admin

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Re: Churchill Tank
« Reply #132 on: January 07, 2015, 02:46:04 AM »
I have removed some posts here - they may be partially returned in the future after I have reviewed them for relevance.
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Offline tankmodeler

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Re: Churchill Tank
« Reply #133 on: January 07, 2015, 04:05:07 AM »
Damn, and I wanted to (and still kind of do) combine a M103 or Conqueror turret with the Black Prince!
If we ever see an injected Black Prince, I promise you can have the turret from my Dragon M103A1. Actually, if you have a resin Black Prince (didn't Accurate Armour do one??) you can still have the turret from my Dragon M103A1. It's certainly no good as an accurate 103 turret...

:-)

Seriously, if you want it, you can have it.

Paul

Offline Volkodav

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Re: Churchill Tank
« Reply #134 on: January 07, 2015, 07:03:16 AM »
Widen the Churchill? ???
Well, if you absolutely needed to fit a Comet turret, I can envision how it could be done, a huge adaptor flange that would fit over the Churchill turret ring and properly support the Comet turret.  Loads would definitely require it to be made out of high-strength steel and it would be a right pain to machine and add significantly to the final vehicle's weight.  Something definitely more suited to whif-dom than reality.

There's a photo I've seen of a Matilda II with a Cromwell / Cavalier turret that uses that method, apart from the turret just looking wrong on a Matilda you need to look closely to see the built up area.  British tanks, for the most part, also have a lower profile than US tanks, but also lack the sponsons of the M-3/4 etc.which is how the M-4 manages to have such a large diameter turret ring.

  Technically the Churchill and the Cromwell for that matter, could have their hulls built up over the tracks but that would increase weight and profile height, making the tank a bigger target, while the new superstructure would require thinner armour for stability reasons as well as perhaps a reduction in existing armour to control weight growth.  Overall widening the hull may be both technically easier and result in a better balanced design.especially if it incorporates a better engine as well.

The issue is the UK really needed, either a clean sheet design that could easily accommodate the 17pdr, or an intermediate tank gun that could replace the 75mm while providing superior anti-armour performance to the 6pdr.  It all seems to come back to some incorrect assumptions made during development in regards to the size and platform impact of the 17pdr, that had it been realised would have resulted in design changes to address the problem.

Offline Rickshaw

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Re: Churchill Tank
« Reply #135 on: January 07, 2015, 08:43:28 AM »
The issue is the UK really needed, either a clean sheet design that could easily accommodate the 17pdr, or an intermediate tank gun that could replace the 75mm while providing superior anti-armour performance to the 6pdr.  It all seems to come back to some incorrect assumptions made during development in regards to the size and platform impact of the 17pdr, that had it been realised would have resulted in design changes to address the problem.

Enter the Centurion.  A clean sheet design and the first complete one undertaken by the Ministry of Supply's Department of Tank Design, rather than the individual manufacturers (the Department had up till that point acted as a contracting department, requesting the individual manufacturers to design the vehicles themselves).  The Department was much closer and more clearly understood the requirements of the end users and so the Centurion incorporated the lessons learned from the previous five years of warfare.   It was intended to fulfil both cruiser and infantry tank requirements.  In the end, the infantry tank version wasn't built, beyond a few prototypes (it incorporated heavier armour and wider tracks IIRC).

You should also remember the 17 Pdr was designed first and foremost as an anti-tank gun, not a tank gun.  Only after it's development was the idea of putting it into a tank first mooted.  The British suddenly found they didn't have a turret big enough to accept the weapon and so it became a seemingly endless chase to either adapt or built a new vehicle.  Vickers tried to fix that by developing their high velocity 75mm gun, which eventually morphed into a 76.2mm weapon firing the same ammunition as the 17 Pdr with a shorter, fatter case and was finally designated the 77mm (despite actually remaining 76.2mm).  While it's velocity wasn't quite as good as the 17 Pdr. it was close enough for most jobs.

An argument could be made that the Centurion was the first successful design to be able to mount the 17 Pdr properly.  In that case, the decision made very early on was to give it as large a turret ring as could be managed, which meant it was able to survive the succession of up gunning, from 17 to 20 Pdr and finally 105mm.   The Firefly was only ever an extemporised weapon, forced on the RAC by circumstance (and the happy coincidence that the RAAC had done the experimental work with it's twin 25 Pdrs mounted in a Sentinel in Australia which proved it was possible).  As it was, it was only accomplished by turning the gun on it's side.  The Black Prince, was the last gasp of the "old school" and they failed as they usually did by trying to do more with less and failing to produce a balanced design as far as it's engine power went.

One thing I've never quite understood is why the Allies never followed the German route in seeking a higher velocity tank gun - lengthening the barrel and increasing the chamber size of the standard 75mm tank gun.   It would have made a better tank killing weapon without necessarily needing a new mounting.   As it was, they stuck with a gun which was adequate in 1942 until the end of the war, when it was decidely passe.  While the primarily role of the tank in US doctrine might have been infantry support, a higher velocity 75mm would have taken little from that and ensured the tanks had a better weapon with which to defend themselves against other tanks.

Offline tankmodeler

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Re: Churchill Tank
« Reply #136 on: January 07, 2015, 10:58:52 AM »
British tanks, for the most part, also have a lower profile than US tanks, but also lack the sponsons of the M-3/4 etc.which is how the M-4 manages to have such a large diameter turret ring.
Absolutely. Another thing to consider is the turret basket under the ring. There needs to be enough room for the crew (and possibly a larger crew if you are going from a two-man to a three-man turret) to work effectively. The Churchill has no effective access to the sponsons so a larger turret ring doesn't help you if you can't install a larger turret basket.

Quote
  Technically the Churchill and the Cromwell for that matter, could have their hulls built up over the tracks but that would increase weight and profile height, making the tank a bigger target, while the new superstructure would require thinner armour for stability reasons as well as perhaps a reduction in existing armour to control weight growth.
I think you may be overestimating the negative effect on stability unless the additional mass is truly egregious, however, keeping the mass in check so the mobility isn't overly affected is a good idea. Of course, compromising the protection can be counterproductive if you've gone to great lengths to increase the firepower through a new turret. The balancing act can be brutal.

Quote
Overall widening the hull may be both technically easier and result in a better balanced design.especially if it incorporates a better engine as well.
The one major problem, especially during WW II, was the relatively narrow railway gauges in both the UK and continental Europe. The Churchill is absolutely at the limit of the UK gauge and actually had to have the air inlet boxes removed for rail shipment, never a good thing for strategic mobility. Widening a tank past the gauge limit wasn't an acceptable option during the war and had a huge (and mostly negative) effect on UK tank design.

Quote
The issue is the UK really needed, either a clean sheet design that could easily accommodate the 17pdr, or an intermediate tank gun that could replace the 75mm while providing superior anti-armour performance to the 6pdr.  It all seems to come back to some incorrect assumptions made during development in regards to the size and platform impact of the 17pdr, that had it been realised would have resulted in design changes to address the problem.
Indeed, the UK was plagued by several factors that all contributed to a string of what were generally really bad tanks. The book "The Great Tank Scandal" does a great job of describing the many ins and outs of why the UK simply didn't get their act together until the Comet. Which, as you say, was fundamentally a clean sheet design that started once some of the background essentials were in place, like a powerful engine, a great gun and a reliable chassis.

Paul

Offline Buzzbomb

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Re: Churchill Tank
« Reply #137 on: January 07, 2015, 02:37:03 PM »
This is an interesting discussion.

Damn, and I wanted to (and still kind of do) combine a M103 or Conqueror turret with the Black Prince!


I have a 1/35 Conqueror (Accurate Armour kit, you can thank me for the injection version announced) and a scratchbuilt Black Prince (no doubt to be announced shortly)
Fossicked them out and some turret swappage and you get.



Offline tankmodeler

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Re: Churchill Tank
« Reply #138 on: January 07, 2015, 09:11:50 PM »
One thing I've never quite understood is why the Allies never followed the German route in seeking a higher velocity tank gun - lengthening the barrel and increasing the chamber size of the standard 75mm tank gun.   It would have made a better tank killing weapon without necessarily needing a new mounting.   As it was, they stuck with a gun which was adequate in 1942 until the end of the war, when it was decidely passe.  While the primarily role of the tank in US doctrine might have been infantry support, a higher velocity 75mm would have taken little from that and ensured the tanks had a better weapon with which to defend themselves against other tanks.
Well, the M1 76mm gun was essentially an attempt to do just that. Longer tube, higher nuzzle velocity and nominally improved AT performance. As it turned out, the AT performance was only a bit better than the 75mm M3 and the HE performance was considerably worse.

The HE performance of the 17 pdr was dismal.

The muzzle velocities needed to really compete with the German armour inevitably leads to guns that have much greater wall thicknesses to deal with the pressures and forces and thus less HE filling and therefore crappy HE performance. There was no way around that. And the US wasn't really happy to ever accept that. Their doctrine continued to lead them to believe that someone other than tanks could be the main weapon against tanks so they figured that they could put the AT performance aside. They were wrong, but they didn't come to terms with that until pretty much the end of the war.

Offline Rickshaw

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Re: Churchill Tank
« Reply #139 on: January 07, 2015, 11:26:28 PM »
One thing I've never quite understood is why the Allies never followed the German route in seeking a higher velocity tank gun - lengthening the barrel and increasing the chamber size of the standard 75mm tank gun.   It would have made a better tank killing weapon without necessarily needing a new mounting.   As it was, they stuck with a gun which was adequate in 1942 until the end of the war, when it was decidely passe.  While the primarily role of the tank in US doctrine might have been infantry support, a higher velocity 75mm would have taken little from that and ensured the tanks had a better weapon with which to defend themselves against other tanks.
Well, the M1 76mm gun was essentially an attempt to do just that. Longer tube, higher nuzzle velocity and nominally improved AT performance. As it turned out, the AT performance was only a bit better than the 75mm M3 and the HE performance was considerably worse.

The HE performance of the 17 pdr was dismal.

The muzzle velocities needed to really compete with the German armour inevitably leads to guns that have much greater wall thicknesses to deal with the pressures and forces and thus less HE filling and therefore crappy HE performance. There was no way around that. And the US wasn't really happy to ever accept that. Their doctrine continued to lead them to believe that someone other than tanks could be the main weapon against tanks so they figured that they could put the AT performance aside. They were wrong, but they didn't come to terms with that until pretty much the end of the war.

The Germans used essentially the same 75mm HE round in all their 75mm tank guns, no matter what length of barrel.  So how did they managed that?

HE doesn't have to be fired at the same MV as AP.    Keeping the MV lower means that the stresses on the HE round are lower and so you don't need thicker walls in your HE rounds and so can have the same filling, keeping it's effectiveness.

Having a longer barrel though, allows you to increase the MV of AP.   L/33, L/43, L/48, L/70....

Admittedly there were also chamber increases as well, from L/48 to L/70 but essentially it remained the same weapon and mount.


Offline dy031101

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Re: Churchill Tank
« Reply #140 on: January 07, 2015, 11:48:10 PM »
Damn, and I wanted to (and still kind of do) combine a M103 or Conqueror turret with the Black Prince!
If we ever see an injected Black Prince, I promise you can have the turret from my Dragon M103A1. Actually, if you have a resin Black Prince (didn't Accurate Armour do one??) you can still have the turret from my Dragon M103A1. It's certainly no good as an accurate 103 turret...

:-)

Seriously, if you want it, you can have it.

 ;D I need to determine if I want to do it in plastic or in digital triangles.  I did buy a bigger house, but it seems like my parents' post-retirement activities will take up plenties of room.

Damn, and I wanted to (and still kind of do) combine a M103 or Conqueror turret with the Black Prince!

I have a 1/35 Conqueror (Accurate Armour kit, you can thank me for the injection version announced) and a scratchbuilt Black Prince (no doubt to be announced shortly)
Fossicked them out and some turret swappage and you get...

Thanks.  It really helps me planning things out.  :)

Those vertical protrusions on the engine deck are a cause of my concern...... as expected  ;)
« Last Edit: January 08, 2015, 01:17:41 AM by dy031101 »
Forget about his bow and arrows- why wait until that sparrow has done his deed when I can just bury him right now 'cause I'm sick and tired of hearing why he wants to have his way with the cock robin!?

Offline Logan Hartke

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Re: Churchill Tank
« Reply #141 on: January 08, 2015, 12:35:40 AM »
Admittedly there were also chamber increases as well, from L/48 to L/70 but essentially it remained the same weapon and mount.


That's not the case, Rickshaw. The KwK 40 and KwK 42 were completely different weapons that fired completely different rounds. Yes, it's true that the Panther's HE round was fired at a much lower muzzle velocity than the AP round, but it wasn't the same round that was used on the PzKpfw IV. They were not the same at all. Different cartridge case, length, shape, propellant charge, and muzzle velocity.



The KwK 40 saw the barrel lengthened from L/43 to L/48, but the L/70 KwK 42 was a totally different weapon, far from just another barrel increase.

Cheers,

Logan

Offline Volkodav

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Re: Churchill Tank
« Reply #142 on: January 08, 2015, 09:16:54 PM »
One gun I am surprised didn't have a longer barrel was the 95mm howitzer although there is probably a perfectly logical reason for the chosen length perhaps relating to the infantry version that didn't in the end enter service but I really don't know. 

As I understand it the weapon was a bit of a Frankenstein using a section of 3.7" AA gun barrel, 25pdr breach mechanism and the 6pdr recoil mechanism and a large counter weight to balance the weapon in the turret.  It apparently also suffered from poor accuracy and low muzzle velocity, although that was probably irrelevant.  Why then didn't they just increase the length of the barrel, removing the need for the counter weight and potentially improving accuracy and increasing muzzle velocity (note I did say potentially as I know there are other factors involved).

Offline dy031101

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Re: Churchill Tank
« Reply #143 on: January 09, 2015, 10:04:00 AM »


I know it will be easier said than done once I actually get around doing something about the idea......
« Last Edit: January 09, 2015, 10:07:51 AM by dy031101 »
Forget about his bow and arrows- why wait until that sparrow has done his deed when I can just bury him right now 'cause I'm sick and tired of hearing why he wants to have his way with the cock robin!?

Offline GTX_Admin

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Re: Churchill Tank
« Reply #144 on: January 10, 2015, 03:41:49 AM »
Interesting…

What about a dedicated SPH based upon the Churchill?  I am thinking of something more than the Churchill VIII with 95 mm howitzer shown below:



Maybe something like a 105mm or 155mm gun?
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Offline Volkodav

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Re: Churchill Tank
« Reply #145 on: January 10, 2015, 04:11:46 PM »
Well the Australian 25pdr setup, developed for the AC3, should fit and the 95mm does have the 25pdr breach mechanism.  The 165mm demolition gun was retrofitted to some Churchill AVREs post war, is a howitzer version of this gun possible?  Actually I do remember reading somewhere that the L9 165mm was originally developed as a replacement CS howitzer for the 95mm.

Offline tankmodeler

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Re: Churchill Tank
« Reply #146 on: January 11, 2015, 10:28:36 PM »
One of the problems with Churchill based SPG variants is the lack of space to work the piece. You would need to build an entire superstructure above the upper track run to provide enough room for a crew to work easily. The 95mm and 165 mm demo guns were not meant for sustained rates of fire so the rather cramped turret of the Churchill was fine. When you are trying to lay down a support mission of 30 rounds on target, that's just not easy at all in any rotating turret and almost impossible in a turret like the Churchill's. The Bishop was the first Brit attempt and the turret was actually a "casemate"; it didn't turn at all. The whole back opened up when firing and the elevation of the 25 pdr inside was limited.

Now, if you are willing to add a full superstructure, kinda like a Priest, above the track-line, then the vehicle itself would easily support it, but there were better vehicles available at the time, so why bother. But it wouldn't be impossible. just clumsy and likely pretty ugly. :-)

It would be kinda interesting to see what someone could come up with, though, as a WHIF.

Paul

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Re: Churchill Tank
« Reply #147 on: January 12, 2015, 02:09:38 AM »

Now, if you are willing to add a full superstructure, kinda like a Priest, above the track-line, then the vehicle itself would easily support it, but there were better vehicles available at the time, so why bother. But it wouldn't be impossible. just clumsy and likely pretty ugly. :-)


That was more what I was thinking.  As for practicality…bah!
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Offline Buzzbomb

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Re: Churchill Tank
« Reply #148 on: January 12, 2015, 09:48:58 AM »

Now, if you are willing to add a full superstructure, kinda like a Priest, above the track-line, then the vehicle itself would easily support it, but there were better vehicles available at the time, so why bother. But it wouldn't be impossible. just clumsy and likely pretty ugly. :-)



That was more what I was thinking.  As for practicality…bah!


Something like this but using more space over the track guards for ammo storage and the like, which makes a lot of sense.


Offline Logan Hartke

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Re: Churchill Tank
« Reply #149 on: January 12, 2015, 10:09:54 AM »
The Churchill Toad extended the superstructure over the tracks, or at least appears to have. That should provide you with a lot more internal space, going with a similar configuration.







Cheers,

Logan