Improve the Churchill tank.
- Thread starter McPherson
- Start date
Should we improve the tank from its original configuration or can we change how its design prior to entry into service?
With that presentation as the start point, and the background data, do what you can to improve this British tank.
Happy speculation!
McP.
P.S. This tank is a hoot as to Human ergonomics applied disasters that somehow managed to perform well.
McPherson
Banned
Lets go with the Churchill Mark I (Tank, Infantry, Mk IV (A22) Churchill ) and lesson learn forward. The type example in the video is a Churchill VII. I think there is considerable room for speculative improvement from 1941 onward. I happen to think that the Churchill VII is not as good as it should and could have been.
marathag
Banned
First, need to get the Brass Hats to decide what an Infantry Tank was to actually do?
I mean 'Infantry' is right on the Tin, but what do Infantry need/want the Tank to do for them?
No particular order
Shoot machine guns at enemy infantry
Shoot HE in direct fire at bunkers and other enemy strongpoints, and infantry
provide Radio Link back to HQ
Throw Smoke to hide friendly movement
Defend against enemy tanks that are attacking friendly tanks and infantry
have enough armor to not be easily knocked out by common enemy AT guns and enemy tanks
have some AAA capability against enemy aircraft
be reliable enough to get to the battlefield in the first place
As can be seen, the existing Churchill didn't check many of those boxes, being undergunned with cannons firing only solid shot, and only the
first marks had the hull cannon that war really more a breechloading mortar for tossing smoke, little HE carried. Very unreliable until 1942
That the Churchill was very slow was not as much an impediment in combat as some might think.
I mean 'Infantry' is right on the Tin, but what do Infantry need/want the Tank to do for them?
No particular order
Shoot machine guns at enemy infantry
Shoot HE in direct fire at bunkers and other enemy strongpoints, and infantry
provide Radio Link back to HQ
Throw Smoke to hide friendly movement
Defend against enemy tanks that are attacking friendly tanks and infantry
have enough armor to not be easily knocked out by common enemy AT guns and enemy tanks
have some AAA capability against enemy aircraft
be reliable enough to get to the battlefield in the first place
As can be seen, the existing Churchill didn't check many of those boxes, being undergunned with cannons firing only solid shot, and only the
first marks had the hull cannon that war really more a breechloading mortar for tossing smoke, little HE carried. Very unreliable until 1942
That the Churchill was very slow was not as much an impediment in combat as some might think.
Fearless Leader
Donor
The Rolls-Royce Meteor was developed around the same time. Perhaps stick that in there instead of the Bedford engines to help with it being under-powered and a bit of the mechanical reliability?
marathag
Banned
reoccurring problem with early British tanks, they used a mild steel framework that hardened plates are bolted/riveted to, rather than full monocoque like everyone else
Now powerplants
Churchill
Bedford Flat 12 1296 cubic inches max rpm??? 350hp@2000
4 speed
Torque 960 ft lbs@1600 rpm 12.5 mph
M4A1
Continental R975 973 cubic inches governed max rpm 2400 400 hp@2,400 rpm
5 speed
Net Torque 940 ft lbs@1700rpm 24 mph
M4A2
GM twin Diesel 850 cubic inches max rpm 2900
5 speed
Net Torque 1000 ft lbs@1400rpm 25 mph
M4A3
Ford GAA 1100 cubic inches max rpm 2600
5 speed
Net Torque 950 ft lbs@2200rpm 28 mph
M6
Wright G200 1832 cubic inches max rpm 2300
Electric
Max torque 1850 ft lbs@2300rpm 22 mph
Torque is what moves vehicles, not HP, lower the RPM the better. needing higher RPMs with the radial in the M4A1, resulted in more clutch wear
Note that of the five listed, the Churchill had the worst transmission, and best differential, fully regenerative, able to neutral steer.
The US Cletrac had a fixed ratio for a turn in a given gear.
What that mean?
Churchill could turn tighter, or wider, as driver desires
What you could do is pretty well what they did do as the war progressed. Over any but good ground the speed of the Churchill was on a par with it's peers and adequate for the task. It's low rev torque and steering made it mobile in bad and tight ground. The QF75mm gun was up to the infantry task. The hull MMG was useful in the infantry support role and these were being dropped in peer tanks to make room for larger shells as guns got bigger but a useful position in the Churchill's role and justified the flat front with thick armour. Maybe some ergonomic and better hatches would be good development. I have never met a Churchill crewman who wanted to be in anything else during the war.
With that presentation as the start point, and the background data, do what you can to improve this British tank.
Happy speculation!
McP.
P.S. This tank is a hoot as to Human ergonomics applied disasters that somehow managed to perform well.
I would have its replacement developed faster (Centurion in serial production by Mid 44 in field service by end of year)
Maybe a better engine version from 42/43 - Meteor - perhaps a sloped frontal glacis
Otherwise its mobility and ability to overcome some pretty serious terrain (including gradients that would burn out most other tanks of the days gear boxes) was unsurpassed as was its ability to take on specialist tasks
Its crews bloody loved it
Very reliable in spite what the interwebs might tell us
Bigger hatches, little more power and speed, a duel purpose gun from the start and don't rush it into service before all the needed testing and development work is done. It wasn't ready when it entered service, the factory knew it, the army knew it and the crews got the idea when they saw the manual had a large number of blank pages for them to write down how they fixed the bugs.
The Merlin is needed for the Hurricane, Spitfire, Mosquito, Lancaster, and others; good luck trying to get a share of its production. More likely in my opinion if you're looking at converting aircraft engines is Rolls-Royce's Kestrel which generated 475 bhp on pool petrol when they tested it alongside the converted Merlin in our timeline.
Of course once you add extra power it's going to start stressing other parts, thankfully the Merritt-Brown gearbox had been developed by the mid-1930s and Horstmann suspension in the early 1920s. The tracks are still going to be dodgy until they change the materials and redesign them IIRC.
AIUI the Meteors were basically rejected Merlins. At least a first. Could be very wrong on that one. I am much more confident that the Churchill had a Merrit-Brown gearbox.
I agree with an engine and hatch upgrades as improvements but I would go with the 77mm not the 17 per. It is almost as good and is much smaller.
McPherson
Banned
More fuel on the bonfire.
The Elbonians are really dumb.
The Black Prince is a disaster. So it shows us what really does not work in product improving the basic Churchill Mark I.
Now what could be done with the 137.16 cm (54 inch) ring diameter base A22 (Churchill Mark 1).
1. Improve the hatches to be counter-sprung round mouseholes, plug set type (no side hatches wanted. top down entry only.)
2. Overhang a larger in volume new design turret over the ring race so the goddamned turret crew has elbow room not to bang each other in the face as they pass around the ammunition. Ditto, put in a BUSTLE so the radio can be shoved backwards out of the TC's way and the TC and the TC seat can be moved backwards to give the gunner room to sit up straight and actually look through a CENTERED roof mounted periscope sight.
3. Rearrange the ammunition stowage to allow the loader (in the roomier though narrow ringed turret to reach to his left and right to unclip ready rounds off the bracket stowage of his side of the turret overhang.
4. Did I mention that the ballistic shape of the new turret should be ellipsoidal in 2-d so that skip-off presents to incoming fire will be superior to the slab-sided boxy design?
5. Also use an external gun mantlet to increase the volume forward. And balance the turret mass so you do not get side sling?
6. Commander's cupola. I noticed how BLIND the poor TC was buttoned up. I thought an Australian Sentinel was terrible.
7. Tracks need a lot of work. Hint: Sherman solutions.
8. The Glacis is a shot trap. Fix it.
9. The bow machine gun is a shot trap and limited arc. Fix that too.
10. Nothing says ergo goof up like the crewmen having to angle off their seats to use the offset vision blocks and periscopes. The gunner's work station is really bad in this regard.
11. Fire suppression system is substandard.
12. Crew escape routes (hopefully fixed with the new hatches) is TERRIBLE.
13. Install and infantry telephone and a radio set cued for same infantry radio communication, since it is an INFANTRY tank.
14. Relocate the smoke grenade launcher so the TC can actually use it.
15. Put in a blower to clear out the farts.
16. Put bins somewhere to carry all the outside the tank clutter of tools and personal effects that will otherwise hog up room inside the tank.
17. Reroute the air intakes and exhausts to the engine so these do not become a shoot me or grenade me here mission kill bullseye on the tank.
18. As you put antimine and grenade mesh on the engine deck, how about making the mesh stout enough and equipped with infantry handholds so the infantry Tommies can hitch a ride on the tank as it road marches?
Just some thoughts on the Mark 1.
McP.
The Elbonians are really dumb.
The Black Prince is a disaster. So it shows us what really does not work in product improving the basic Churchill Mark I.
Now what could be done with the 137.16 cm (54 inch) ring diameter base A22 (Churchill Mark 1).
1. Improve the hatches to be counter-sprung round mouseholes, plug set type (no side hatches wanted. top down entry only.)
2. Overhang a larger in volume new design turret over the ring race so the goddamned turret crew has elbow room not to bang each other in the face as they pass around the ammunition. Ditto, put in a BUSTLE so the radio can be shoved backwards out of the TC's way and the TC and the TC seat can be moved backwards to give the gunner room to sit up straight and actually look through a CENTERED roof mounted periscope sight.
3. Rearrange the ammunition stowage to allow the loader (in the roomier though narrow ringed turret to reach to his left and right to unclip ready rounds off the bracket stowage of his side of the turret overhang.
4. Did I mention that the ballistic shape of the new turret should be ellipsoidal in 2-d so that skip-off presents to incoming fire will be superior to the slab-sided boxy design?
5. Also use an external gun mantlet to increase the volume forward. And balance the turret mass so you do not get side sling?
6. Commander's cupola. I noticed how BLIND the poor TC was buttoned up. I thought an Australian Sentinel was terrible.
7. Tracks need a lot of work. Hint: Sherman solutions.
8. The Glacis is a shot trap. Fix it.
9. The bow machine gun is a shot trap and limited arc. Fix that too.
10. Nothing says ergo goof up like the crewmen having to angle off their seats to use the offset vision blocks and periscopes. The gunner's work station is really bad in this regard.
11. Fire suppression system is substandard.
12. Crew escape routes (hopefully fixed with the new hatches) is TERRIBLE.
13. Install and infantry telephone and a radio set cued for same infantry radio communication, since it is an INFANTRY tank.
14. Relocate the smoke grenade launcher so the TC can actually use it.
15. Put in a blower to clear out the farts.
16. Put bins somewhere to carry all the outside the tank clutter of tools and personal effects that will otherwise hog up room inside the tank.
17. Reroute the air intakes and exhausts to the engine so these do not become a shoot me or grenade me here mission kill bullseye on the tank.
18. As you put antimine and grenade mesh on the engine deck, how about making the mesh stout enough and equipped with infantry handholds so the infantry Tommies can hitch a ride on the tank as it road marches?
Just some thoughts on the Mark 1.
McP.
The A22 Churchill was merely Vauxhall's successor to the Harland & Wolff's A20 infantry tank, which itself was originally a turretless tank with sponson armament converted to have a simplified version of the Matilda II's turret. Since neither company was experienced with tank building and Vauxhall was mostly improving on H&W's design, the Churchill kept archaic design features such as the envelopping tracks on a double girder hull, and a narrow fighting compartment and turret ring diameter (limited by the need to use Matilda II's turret).
Naturally by the time the Tank Board was formed in mid-1940 and was looking over the design, France had fallen and the British wanted new tanks ASAP, so while some like Pope wanted to start from scratch and others like Stern went on to design the TOG tanks (tbh the engineers in charge of the TOG did a really good job, making a tank that was easy and cheap to produce and had impressive performance for the time, but the requirements were completely stupid), expediency and interference from the Prime Minister led to the A22 being pursued as is.
Thus while delaying production could have helped, especially to produce more cruiser tanks as the Tank Board desired (there was strong imbalance in production between either type), it was not possible in the pyschology of the time.
Arguably the British should have been able to design a proper replacement based on the Cromwell to replace the Churchill by 1943 as intended, but did a rather poor job at it while Vauxhall pushed hard to save its design and the Churchill eventually proved itself.
Similarly, some improvements to the Churchill didn't happen until the Churchill VII because of the need to not disrupt production, because it was thought this tank would be replaced quickly enough, and because only a major redesign could justify those changes. This is why the welded hulls designed by Babcock & Wilcox, built in the end of 1940 and ballistically tested by mid-1942, were not introduced until 1944. So IMO the plausible way to go requires two approaches to be explored at the same time (and ideally, cancell the TOG earlier to have the SVDC work with Vauxhall): improvements that can be quickly integrated in current production, and a complete redesign to enter service by 1943 or 1944.
Current production options:
- have Leyland continue development of its diesel engine beyond December 1942 when trials ended. (possible introduction in mid-late 1943)
- based on early testing showing how it was impossible to use the gun on the move in 1941, have future turrets (for Mk IV and later in particular) featured geared elevation mechanisms and an external mantlet to increase room in the turret and possibly gun depression (supposedly it shouldn't interfered with hull crew hatches because the NA 75 conversions with Sherman mantlets worked). The external mantlet would also remove tendency of the internal version to be jammed by small arms fire and might allow an extended bustle to balance and get further space, but this must be limited in weight growth because the turret ring won't handle it.
- based on early 1942 trials in North Africa, introduce armored ammunition bins (4mm thick if armor steel, 6mm if mild steel) to reduce the chance of ammunition fires due to spall hitting them. Even if that means less ammo carried.
- based on the same trials, future turret mounts should have the BESA moved to the right side and improve the sights for long-range shooting
- turret style could be modernized to the level of the Vauxhall Cromwell's proposal (that was in late 42 IIRC) with external mantlet
For a longer-term redesign (kind of a mix between the BP and Churchill VII) on top of VII improvements:
- have the front idlers moved down like on the Black Prince to improve the driver's vision
- get rid of the stepped front hull design to incorporate 45-55° sloped armor. Ideally the angle would be set to increase the length of the roof, allowing for larger crew hatches or clearance for an external mantlet. This would allow to match or even exceed the level of protection of the Churchill VII, with reduced weight, reduced plate thickness (simplifying production or improving plate quality) and increased internal volume. This would also allow the removal of the weakpoints the MG mount and driver's viewport represented. This might not be compatible with a hull BESA MG, in which case the hull gunner can be removed to make place for a revised ammunition stowage.
- redesign the engine bay to use the RR Meteor if allowed. (This was actually suggested in about October 1943 for BP, but obviously too late to matter. The MG was to be sacrificed if it could not be used)
- increase size as necessary to either: match the Cromwell's 60" turret ring diameter and standardize turrets while increasing space OR get all the way to BP or Comet-sized turrets, or something inbetween to use either the 17 pounder or 77mm gun.
Indeed, it would allow for a lighter and smaller design than the BP.
Attachments
That one actually can't be fixed quickly because the tank would be too high for British railway requirements, and the high early cupolas just got the commander killed. This was not a British problem because the Sherman also abandonned proper cupolas until late 1943 or 1944, by which time the Churchill VII received similar low-profile designs with all-round vision.
What was needed was to drive the OTL improvements earlier and add in the ergonomics suggested above.
If one wanted greater changes without gross industrial alterations, I like the idea of the Leyland diesel engine version. The extra torque will shift more weight. Given the actual role replacing the QF75mm with a QF25 Pounder would be more useful than shoehorning in a 17 Pounder. Nice if it can get full elevation. It would not just give it a bigger HE bang in supporting infantry but allow it more flexibility in having a decent indirect fire capability. Worth eliminating the (otherwise useful) hull MMG to carry more rounds.
If one wanted greater changes without gross industrial alterations, I like the idea of the Leyland diesel engine version. The extra torque will shift more weight. Given the actual role replacing the QF75mm with a QF25 Pounder would be more useful than shoehorning in a 17 Pounder. Nice if it can get full elevation. It would not just give it a bigger HE bang in supporting infantry but allow it more flexibility in having a decent indirect fire capability. Worth eliminating the (otherwise useful) hull MMG to carry more rounds.
You are indeed correct, I was getting my inter-war tanks mixed up. As I've posted previously the frustrating thing is that the UK had all of the parts, or clear development paths to them, for a successful tank but due to various reasons were never able to get there until right at the end.