Sir John Valentine Carden survives.

[MattII]

The QF75mm did what was needed, if not what crews very reasonably wanted by 1944. It was weak in AT capability but was fitted to the OTL late production Valentines and many earlier OTL Valentines were 6 Pounder armed so we can keep close to OTL. Given a slightly earlier 6 Pounder then choosing a 75mm is just a matter of choosing a larger barrel dimension and chamber from the start. It asks no more of industry than the 6 Pounder and has commonality with the French 75mm ammunition. My father was involved in transporting captured French 75mm ammunition to Egypt from Syria where it was mated with captured German AP and used in Grants in the Western Desert. There is no need to stretch the Valentine further than OTL. A Valentine national tank gives industry time to digest the lessons of actual tank warfare and prepare a design to carry the 17 Pounder in a sound hull with a Meteor engine with careful trials bringing in a better 17 Pounder Comet/Centurion as the AH Cromwell to replace the Valentine in service as the new national tank.

1) The 17-pounder hasn't been conceived yet, let alone designed or built.
2) The Tank mounted 17 pounder wouldn't be the best gun to mount, a stonking big thing, with limited accuracy (the Sabot rounds were useless at any significant range), and no HE round.

 

[yulzari]

Agreed, the 6 pounder was an excellent gun, and would be effective up until Overlord. (providing an HE round was provided for it)
The Valentine suffered, under-powered and with too small a turret. It was, however much more reliable than the Convenater and Crusader.
The Covenanter actually had a well shaped hull, but the totally weird engine cooling system and the much too small turret ring pretty much doomed that tank.
The Crusader was better, but still had a cramped turret, small turret ring and cooling problems.

If the original specifications actually requested a capabiity of mounting the 6 pounder gun from the beginning, instead of the 2 pounder, this would undoubtedly made for better designed tanks in the 1930's.

There was an HE round for the 6 Pounder and there was a brisk trade in them between British infantry who had them and US infantry who did not.

 

[ArtosStark]

IIRC the places where lack of HE were really a problem were in North Africa, and could be put down to poor tactics as much as poor equipment. I would say the 2-pounder is fine for the early war. If you can avoid the slow down on the 6-pounder it is good till mid war. At that point you are getting big enough guns that HE becomes effective.

AIUI when the Vickers HV 75 was created it was intended to be able to have US HE with 17 pounder velocity. Except because the gun and turret teams of the Cromwell were not on the same page, it wasn’t going to fit. So they bored out the 6pounder to take US ammunition, increasing HE capability but losing penetration. I believe the US 75 ammo at the time had significant problems with shatter gap. The conceptual problem I see with the HV 75 is that 75 mm ammo was not produced in Britain at the time. Their equipment was mostly for 76.2 (from the 3” 20 cwt which was the basis for the 17 pounder. Vickers took it down to 75 mm for the HV 75 then when that didn’t work, they took it back up for the 77mm. I would say just skip the HV 75 and go straight for the 77 mm. It has smaller HE than the US 75 but enough to be useful (1.28 pounds compared to 1.47 in the US75) with penetration close to the 17 pounder. And it had a shorter breech so it could more easily fit in a tank turret.

 

[sonofpegasus]

In order to fit in with OTL British armour doctrine I would advocate the following;
Introduction of the 6lb tank gun as early as possible, say late 1939 and the introduction of a close support version using an HE chucker based on the same gun bored out to 75mm (basically your QF75). Later wartime experience will show that the QF 75 needs AT ammo as much as the 6lb,r needs HE.

 

[Merrick]

the 6 Pounder to QF75mm is only a new barrel so by 1940 the gun going into new British tanks if the ROF QF 75mm gun with good HE and capable of killing any tank on the planet. All it needs is a reliable hull to carry it around.

This. Realistically, any of the guns mentioned upthread would do the job in 1939-43. Whether we're talking about the 6-pdr with HE, the 13-pdr, the 75mm or some version of 3", it's going to have a useful HE round and enough AP punch to handle mid-model PzIII/IV, never mind Pz38t, PzII and whatever trashcans the Italians put out. The issue is getting it on a viable tank and getting the tank to the front in numbers.

As for the Valentine, if you offered it to me for the British in 1940 i'm biting your hand off. if you offered it to me in 1940 with the 3 man 2 pounder turret I bite your hand, arm and shoulder off. The problem is it really does have limited room for growth and is too slow. By the time you are into 42 it is pretty much out of contention and past that not worth it apart form as a hull for things like the Archer. The thing is though make it a bit bigger so it can take a 3 man 6 pounder turret and make it 5mph faster, 10 if you can manage it and it is perfect until late 42 and still really good until early 44.

Also this. The idea of building a standard chassis that will remain viable throughout the war and can be used as a basis of a family of TDs, SPGs, APCs and whatever - a British equivalent of the PzIII or PzIV - is a very good one. OTL the British wasted far too much time and effort on a huge multiplicity of designs, mostly built in small numbers and then discarded. The trouble with the OTL Valentine is that it is juuust too small to be that chassis. It was solid enough when it came out in 1941, but it was always slow, the armour could not be upgraded, it took a shoehorn to get the big gun into the turret and the ergonomics were correspondingly poor. There's a reason why the British retired the 6-pdr Valentines quickly and the 75mm version never reached the front at all. Plus the story of the Valentine derivatives isn't great - the Bishop was a bundle of design flaws that was quickly discarded once the M7 became available and the Archer was only suitable for the defensive battles the British were no longer fighting.

What the British need to do is get a chassis in the 20 ton range (with the potential to go up to 25t later), find an engine that will move it at 20-25mph, pick a suspension (doesn't matter which, so long as they test it enough to get the bugs out of it), pick a gun (again, doesn't matter which so long as it fits comfortably into a turret on top of the aforementioned chassis) and get the whole thing into volume production by 1939, so it is coming off the line in numbers in 1940.

What they don't need to do is get into a massive turf war of my engine vs your engine, your suspension vs his suspension, my gun vs all your guns, everyone's theory of tank operations vs everyone else's theory of tank operations and hit 1938-9 with a bunch of dodgy prototypes, some of which are then ordered into panic production once they realise the war's starting and no-one's brought the tanks.

 

[Rickshaw]

You do realise that the RA Artillery Regts, which were issued with the Archer were quite pleased with it and used it successfully in NW Europe quite successfully. It was designed to get out of a position quickly, which is why the gun faced the rear. It could do so quite easily.

 

[sonofpegasus]

The rear facing gun of the Archer also had a second advantage, in that unlike front mounted long barrelled guns there was not the problem of making the vehicle nose heavy which increased the chance of ploughing the long barrel into the ground when surmounting banks, crossing ditches or sharp down hill gradient changes.

 

[Schlock]

Considering a gun in the 3in range, Vickers have got a gun that will do the job that is already in production, the Model 1931 75mm Anti-Aircraft Gun. It comes with an L43 barrel, and the HE ammunition is a 14lb shell mated to a 495x102 case, which will seriously out perform the US M2-M6 series and isn't going to fall all that far short of the 77mm HV gun capabilities.

 

[marathag]

The leap however of going from getting the 6 pounder a year early to then changing it to a 75mm almost immediately to get a good HE round by 1940 is a bit convoluted.

Paying more attention to what the Soviets were doing with the L/26 76mm howitzer, that still used the same 76x385R ammo as the field gun, AP, HE, Canister, smoke

That stubby barrel still allowed a 61mm armor penetration at 500 meters

 

[Bougnas]

Think of the 1938 specification tanks, the Covenanter and Crusader, if they were built for and in mind of the 6 pounder you get a bigger heavier tank yes but one with a better gun and more armour.

The Covenanter actually had a well shaped hull, but the totally weird engine cooling system and the much too small turret ring pretty much doomed that tank.
The Crusader was better, but still had a cramped turret, small turret ring and cooling problems.

If the original specifications actually requested a capabiity of mounting the 6 pounder gun from the beginning, instead of the 2 pounder, this would undoubtedly made for better designed tanks in the 1930's.

The irony is that since the Meadows D.A.V engine was pretty much purpose-made for the Covvie, it could really have been a more powerful engine from the start if it was required. The problem is that the British did exactly the same mistake as the Germans did between 1938-1941 with the VK 20. series: effectively redo the same thing as before more efficiently.
The VK 20. kept the same armament as the Pz III and IV (a 50 or short 75mm gun) in a relatively similarly-sized turret, the same 300hp, the same 50mm of armor that the Pz III and IV eventually got in late 1940-1941, and roughly the same size and weight for the armor. Sure, they were purpose-built with this weight and armor in weight so the VK 20.s would likely have ended up more reliable and easier to produce than their predecessors, with maybe a less overloaded suspension but nonetheless there was no real improvement and this is why they were quickly abandonned to start the VK 30. program once Soviet T-34s and KV-1s were met in Barbarossa.

The Brits did the same pretty much at the same time, asking for new Cruisers tanks that were smaller and lighter than their predecessors and intended with 30-40mm of armour in mind, but still with the same damn power rating for the engine, the same gun in spite of the fact that a new one was in development, and the armor wasn't exactly new as the early Cruisers got add-on armor anyway. Sure the British had some reason to do this as the heavy A16 was a complete disappointment, but nonetheless the requirements were very unimaginative as the 6pdr wasn't required to be able to be carried, and the D.A.V wasn't even asked to get the same 340hp as the Liberty it was supposed to replace! And to be fair when you are replacing an older engine you would probably include a quantum improvement in power, not just getting to the same level. The Brits could frankly have asked for 400hp at least.
That would make a larger and heavier vehicle that can take the 6pdr much easier to achieve without jeopardizing mobility.

Hopefully, Carden's experiments with the Eagle IX may very well give the British the necessary evidence to ask for a more powerful engine.

 

[MarcH]

This. Realistically, any of the guns mentioned upthread would do the job in 1939-43. Whether we're talking about the 6-pdr with HE, the 13-pdr, the 75mm or some version of 3", it's going to have a useful HE round and enough AP punch to handle mid-model PzIII/IV, never mind Pz38t, PzII and whatever trashcans the Italians put out. The issue is getting it on a viable tank and getting the tank to the front in numbers.

True but going for the 6 pounder means you also get a good AT gun. Its small enough to be concealable whilst still doing the job until the end of the war. For that reason alone it is worth developing.

 

[marathag]

True but going for the 6 pounder means you also get a good AT gun. Its small enough to be concealable whilst still doing the job until the end of the war. For that reason alone it is worth developing.

And develop it farther than OTL, like the Soviet ZiS-2 57mm, with a L/70 barrel for even higher velocity.
The QF 6pdr was slightly better than the US M3 75mm. You need to make the 57mm a lot better, for it to stick around.

 

[Cryhavoc101]

A big problem (if not the biggest with British tanks in WW2) was their appalling reliability. It doesn’t matter how good they are if only half of them are available due to mechanical issues. Would Sir John living and continuing at Vickers have any effect on this? And if he does, how big an effect would more reliable tanks have on the British Armies performance?

The reliability issues particularly early war was down to the tanks being rushed to being sent abroad and turning up In North Africa often missing parts and arriving without spares, tools and manuals. Broken down tanks were often fixed using parts stripped from non runners. Those parts themselves often life expired. Sherman’s were sent with spares including an entire spare engine boxed on the rear deck. This reflects the expectation of the US was that where ever it fought was likely to be 1000s of miles away and not the other side of the English Channel. And I suspect learnings from the earlier British experience.

 

[Merrick]

You do realise that the RA Artillery Regts, which were issued with the Archer were quite pleased with it and used it successfully in NW Europe quite successfully. It was designed to get out of a position quickly, which is why the gun faced the rear. It could do so quite easily.

I've seen multiple assessments of the Archer, ranging from "complete joke" to "quite useful in its designed role". Viewed as a straight-up replacement for a towed anti-tank gun, it has a number of obvious advantages, the only real downside being that it's harder to hide. Viewed as a tank-destroyer in the M10/ Marder/SU-76 mould, it has a really obvious problem.

The rear facing gun of the Archer also had a second advantage, in that unlike front mounted long barrelled guns there was not the problem of making the vehicle nose heavy which increased the chance of ploughing the long barrel into the ground when surmounting banks, crossing ditches or sharp down hill gradient changes.

And of course the big disadvantage that the vehicle is restricted to firing from prepared static positions, and hence is of little use on the advance and less in a mobile armour battle. The fact that no-one else, not even the Germans in their most wunderwaffe moments, thought to build a tank destroyer/SP gun with the weapon pointed backwards suggest that this was a fairly major handicap. (The rear-facing gun, AFAIK, had nothing to do with its planned use, and all to do with not being able to fit the gun on the chassis in the conventional orientation without more barrel overhang than they were comfortable with - too-small chassis again!)

 

[andys]

So why couldn't a Merkava-type arrangement be made, with the engine at the front and the fighting compartment at the rear? That allows a single chassis to be a tank, SPG and APC (and other types such as engineer and command, etc.).

 

[NotBigBrother]

Viewed as a tank-destroyer in the M10/ Marder/SU-76 mould, it has a really obvious problem.

Nitpick- SU-76 was an infantry support SPG, not a tank destroyer as SU-85 and SU-100 were.

 

[MarcH]

So why couldn't a Merkava-type arrangement be made, with the engine at the front and the fighting compartment at the rear? That allows a single chassis to be a tank, SPG and APC (and other types such as engineer and command, etc.).

Not a bad Idea, at least for an interim tank. You could reasonably design an AFV that could take up to a 6 pounder whilst being able to also have an extendable rear compartment for troops etc. The Issue I think your likely to run into is the inevitable push for Christie suspension. While reasonable for it's time it does eat up a fair bit of internal space so the engine front layout makes less sense unless your building a particularly wide tank.

 

[Glyndwr01]

So why couldn't a Merkava-type arrangement be made, with the engine at the front and the fighting compartment at the rear? That allows a single chassis to be a tank, SPG and APC (and other types such as engineer and command, etc.).

Vickers Medium Mark II Tank

Vickers had previous with a front mounted engine!

Vickers Medium Mark II - Wikipedia

en.wikipedia.org

.

Command vehicle could be used as an APC?

 

[RetiredCdntanker]

I think we all can agree that the specifications for any tank to be produced in the 1930's should have stated "capable of mounting the 6 pdr cannon".
Even if they were produced with the 2 pdr.
I think we can also agree that the 17 pdr would be too much to ask for at this time.

Originally, the 17 pdr was developed extremely quickly, as it was basically a 3" anti aircraft gun mounted on a modified cradle. However, nobody in the 1930's would envision requiring a cannon that powerful to engage tanks!

1) The 17-pounder hasn't been conceived yet, let alone designed or built.
2) The Tank mounted 17 pounder wouldn't be the best gun to mount, a stonking big thing, with limited accuracy (the Sabot rounds were useless at any significant range), and no HE round.

The 17 pdr was an accurate gun, the APDS was not accurate because they hadn't sorted out sabot separation yet, but the APDS was scarce anyway. With the APCBC round, it was very accurate, and that is the round most used to engage armour. An HE round was available in late 1944, but it still wasn't as good as the 75mm HE round.

 

[Merrick]

Nitpick- SU-76 was an infantry support SPG, not a tank destroyer as SU-85 and SU-100 were.

It was widely used as one, but the 76mm main armament was actually an anti-tank gun. In service, it seems to have multi-classed as SPG, tank destroyer and assault gun - showing the advantage of being able to fire effective HE & AP from the same gun.