Sir John Valentine Carden Survives. Part 2.

[MattII]

The Germans brought Panzer IV’s and the British brought CS tanks. In both cases specialized tanks equipped to do missions that the main tank was ill equipped for. In both cases there in smaller numbers than the main tanks armed with AT guns.

The British CS tanks were primary armed with smoke, with just a handful of HE rounds.

The Soviets did, and that loss was a problem at times. It would be just as useful to condemn Soviet tank doctrine as “f***ing stupid “ for believing that a smaller crew could do the job of a larger one as rail at the British for not doing so.

The Soviets had significantly larger problems in their command structure that overshadowed all of that.

The US started development of the 75 mm as a tank gun at the same time that the British started development of the 17 pounder. However, since the 75 had originally been a failed light AA gun it was significantly more developed and entered service earlier. Either way, it was a requirement that came out of observation of the fighting in France. Prior to that the US requirements were for guns similar to the 2 and 6 pounder. Had the 17 pounder or the 77 mm been available to put into tanks the same time as the 75 mm the British likely would have got just as much use out of it as they did the 75. The HE was smaller but still useful for the requirements and the AT was better.

The American short 75mm was developed from a French 19th century artillery piece. The 3-inch AA gun was found to be too big and heavy to replace it, and while the 76.2mm managed to solve the weight problem, it didn't solve the size one.

Heck, even the French with their stupid 1-man turret realised that having some of their tanks capable of throwing HE was a good idea.

 

[Ramp-Rat]

The argument as to what is the best gun to fit your tank with as its main armament is contentious, as is the mix of ammunition to be carried for it. A lot depends on your doctrine for the use of tanks, and what their role is in your army, supporting the infantry in attack and defence, or as an independent force to attack and defend against your enemies tanks. Excluding the French who were quickly removed from the debate, the four principal tank building nations of WWII each followed different paths. The Germans and Soviets, who principally fought on the open steps of Eastern Europe, both developed armoured assault guns, to fore-fill the infantry support role. While the Americans in Europe stuck with a tank that was lightly armoured in comparison to the German tanks and had a weaker main gun, that did however have a reasonable HE round. There is no comparison between the hole punching ability of the American M3 75 mm, fitted to the Sherman and the 75 mm KwK 40 fitted to late model of the Panzer IV, and the 75 KwK 42 L/50 fitted to the Panther. The Americans got round the problem by developing the so called Tank Destroyer, such as the M10 with the 3-inch M7, or the M36 with the 90 mm M3, and the M18 Hellcat with its 76 mm M1 gun.

The British went down a very different and unique route, all of their own, and started the war with two different sorts of tanks. A very heavily armoured infantry tank, designed for infantry support, and a much lighter cruiser tank to exploit breaches in the enemy line and fight the enemies tanks. Unfortunately the British failed to equip their superb infantry tank with a suitable gun or the gun with an HE round. It wasn’t until they deployed the Churchill Mk VI and Mk VII fitted with the QF 75 mm gun, that they had an infantry tank close to being fit for purpose. However it was the deployment of the Churchill AVRE from mid 1944, fitted with the 230 mm Petard Mortar, that gave the British infantry the ultimate WWII break through tank. Post war the deployment of the Centurion AVRE fitted with the 165 mm L9 Demolition gun, gave the British army right up until the First Gulf War, the ultimate breakthrough tank in the world. I will risk the wrath of Cal Bear by mentioning a current event, the war in Ukraine, were a squadron of Centurion AVRE, would be very useful even today in supporting the Ukrainian assault against the Russians prepared positions.

RR.

 

[MattII]

The American 75mm was capable enough against Panzer IIIs and IVs, and the Shermans' sloped front mean rounds bounced off as often as not.

 

[Orry]

If the priority was to arm the tank against the tank why did the Pz3 get the L/42 and not the L/60?

I thought Hitler had demanded the L/60 and lost his rag when he found out somebody had changed it??

 

[mafio ball]

I thought Hitler had demanded the L/60 and lost his rag when he found out somebody had changed it??

Yes, there was an affair about it.
But I was concerned with the point of replacing the powerful cannon derived from the standard Pak 38 with a weaker one that is not as good at punching tanks.
I have received an answer. Thanks. The stupidity of some institutions is independent of nationality.

 

[CB13]

The British CS tanks were primary armed with smoke, with just a handful of HE rounds.


The Soviets had significantly larger problems in their command structure that overshadowed all of that.


The American short 75mm was developed from a French 19th century artillery piece. The 3-inch AA gun was found to be too big and heavy to replace it, and while the 76.2mm managed to solve the weight problem, it didn't solve the size one.

Heck, even the French with their stupid 1-man turret realised that having some of their tanks capable of throwing HE was a good idea.

Does anyone know in what year the US settled on the 75 x 350R as its primary tank gun round and the 105 x 372R as it's primary medium artillery howitzer round? My assumption is that they likely specified the shell dimensions prior to requesting the gun designs which to my recollection weren't finalized until 1940-1941?

 

[MattII]

Does anyone know in what year the US settled on the 75 x 350R as its primary tank gun round and the 105 x 372R as it's primary medium artillery howitzer round? My assumption is that they likely specified the shell dimensions prior to requesting the gun designs which to my recollection weren't finalized until 1940-1941?

Wikipedia claims that the decision came about even before the first M3 Lee had come off the line, but at that point American Industry didn't have the capability to cast a 75mm turret, so the M3 was a compromise to get the 75mm into the field quicker. Given that the M3 started design work in July 1940, then the decision came no later than this.

 

[Cryhavoc101]

The Lee always struck me as the Americans looking at the Char B and going all gooey eyed and wanting to emulate it

 

[ArtosStark]

The British CS tanks were primary armed with smoke, with just a handful of HE rounds.

True, but both cases show that neither nation could have everything they wanted in one gun at this stage.

The Soviets had significantly larger problems in their command structure that overshadowed all of that.

Doesn’t really change the fact that it was a compromise. And one that caused them problems. Whether it was a worthwhile compromise will depend on your point of view, as do the compromises decided in British tanks.

The American short 75mm was developed from a French 19th century artillery piece. The 3-inch AA gun was found to be too big and heavy to replace it, and while the 76.2mm managed to solve the weight problem, it didn't solve the size one.

No actually. The M2 began life in 1937 in the requirement for a light AA gun to supplement heavier guns and fire the same round as the M1897 artillery. The gun was not actually developed from it. This gun, known as the T6, failed its trials. However, in 1940, and according to some sources in response to reports from France, it was used to develop the T7, which became the new tank 75mm, the M2.

Heck, even the French with their stupid 1-man turret realised that having some of their tanks capable of throwing HE was a good idea.

The French had 3 major tank guns in the battle of France. They had a 37 mm left over from WW1 on their early 30’s tanks that couldn’t even penetrate the armour on a Panzer 3. They had a 47 mm on their more modern tanks which was very similar in performance to the 2 pounder. And they had the 75 mm howitzer mounted in the hull of a few tanks for use against emplacements. That doesn’t exactly seem a better balance than the British had at the same time.

 

[MattII]

The Lee always struck me as the Americans looking at the Char B and going all gooey eyed and wanting to emulate it

Nah, a rushed design to fill the gap between the M2 and the M4.

True, but both cases show that neither nation could have everything they wanted in one gun at this stage.

Not in one gun, or in one vehicle, but the Germans at least recognised the need to have fast, mobile HE throwers around.

Doesn’t really change the fact that it was a compromise. And one that caused them problems. Whether it was a worthwhile compromise will depend on your point of view, as do the compromises decided in British tanks.

The best tank in the world wouldn't have made up for the utter incompetence in the entire Soviet command structure.

No actually. The M2 began life in 1937 in the requirement for a light AA gun to supplement heavier guns and fire the same round as the M1897 artillery. The gun was not actually developed from it. This gun, known as the T6, failed its trials. However, in 1940, and according to some sources in response to reports from France, it was used to develop the T7, which became the new tank 75mm, the M2.

The T6 was based on the M1897, at least according to wikipedia, with a shorter barrel, and a new breech.

The French had 3 major tank guns in the battle of France. They had a 37 mm left over from WW1 on their early 30’s tanks that couldn’t even penetrate the armour on a Panzer 3. They had a 47 mm on their more modern tanks which was very similar in performance to the 2 pounder. And they had the 75 mm howitzer mounted in the hull of a few tanks for use against emplacements. That doesn’t exactly seem a better balance than the British had at the same time.

The 37mm had a HE round. Also, the split wasn't by age, but by weight. the 37mm was the cannon equipped to all of their light tanks, or at least those light tanks that had anything above a MG as the main armament, while the mediums mostly carried the 47mm.

 

[ArtosStark]

Not in one gun, or in one vehicle, but the Germans at least recognised the need to have fast, mobile HE throwers around.

Sure. And the British definitely should have put more effort into HE capability. That is a far way from them being stupid fanatics who proclaim HE heretical.

The best tank in the world wouldn't have made up for the utter incompetence in the entire Soviet command structure.

Again, doesn’t really change my point.

The T6 was based on the M1897, at least according to wikipedia, with a shorter barrel, and a new breech.

It used the same shell and rifling. But that was about it. And that came more from the requirement to use the same ammunition. The recoil mechanism, breech, mount and anything else was new.

The 37mm had a HE round. Also, the split wasn't by age, but by weight. the 37mm was the cannon equipped to all of their light tanks, or at least those light tanks that had anything above a MG as the main armament, while the mediums mostly carried the 47mm.

The largest and most modern HE round for the SA.18 37 mm had all of 56 g of explosive in it. Less than many hand grenades. Other shells with 30 g or less were also used.

Fair enough on the division however.

 

[MattII]

Sure. And the British definitely should have put more effort into HE capability. That is a far way from them being stupid fanatics who proclaim HE heretical.

How many tanks, men, and indeed battles did that lack of HE cost them? It was a lesson that was quite expensive to hammer through their heads.

Again, doesn’t really change my point.

But rather masks it. The best tank in the world will be useless without a trained crew and an

It used the same shell and rifling. But that was about it. And that came more from the requirement to use the same ammunition. The recoil mechanism, breech, mount and anything else was new.

Fair enough.

The largest and most modern HE round for the SA.18 37 mm had all of 56 g of explosive in it. Less than many hand grenades. Other shells with 30 g or less were also used.

Fair enough on the division however.

Yep. The idea was there, even if the execution was abysmal.

 

[Salamander]

It would take something for that particular weapon to see service in WW2. Not saying it couldn't be done, but it wouldn't be easy.

Considering that they were in use during OTL WW2, I'd say it wouldn't be that hard, it just requires decent funding. Case in point, the following all saw service in OTL WW2:

7.5 cm Leichtgeschütz 40 - Wikipedia

en.wikipedia.org

10.5 cm Leichtgeschütz 40 - Wikipedia

en.wikipedia.org

10.5 cm Leichtgeschütz 42 - Wikipedia

en.wikipedia.org

 

[MattII]

Fair point. Bagging a few working examples on Crete (which they did IIRC) would certainly speed things up.

 

[ArtosStark]

How many tanks, men, and indeed battles did that lack of HE cost them? It was a lesson that was quite expensive to hammer through their heads.

Not many. As mentioned the 2 pounder HE shell would have been effectively useless against AT guns. Experiments in WW2 with the 40 mm mortar (with a considerably larger amount of HE than the 2 pounder shell had) found them to be of extremely limited effectiveness against AT guns. Even heavy bombardment by artillery often did not knock out all AT guns in a battery under fire.

The 6 pounder was introduced in combat in May 1942 as an AT gun. A little later as a tank gun. By November 1942 Churchill’s were happily, and effectively using HE in the mountains of Tunisia. Where fights took place at shorter ranges anyway, the HE shell could be effective.

Once there was a gun that could make use of HE, HE was issued. Now if they could have mounted an automatic, as Allen did with the Pom-Pom, things may well have been different. But as it was…

 

[MattII]

Not many. As mentioned the 2 pounder HE shell would have been effectively useless against AT guns. Experiments in WW2 with the 40 mm mortar (with a considerably larger amount of HE than the 2 pounder shell had) found them to be of extremely limited effectiveness against AT guns. Even heavy bombardment by artillery often did not knock out all AT guns in a battery under fire.

That wouldn't have been too bad if the CS tanks hadn't been almost completely derived of HE as well. CS tanks with HE would have helped in a few places, especially if they'd had enough of them (they didn't though, usually).

The 6 pounder was introduced in combat in May 1942 as an AT gun. A little later as a tank gun. By November 1942 Churchill’s were happily, and effectively using HE in the mountains of Tunisia. Where fights took place at shorter ranges anyway, the HE shell could be effective.

And yet, they still moved to the 75mm when given the chance.

Once there was a gun that could make use of HE, HE was issued. Now if they could have mounted an automatic, as Allen did with the Pom-Pom, things may well have been different. But as it was…

See above. The early CS tanks were armed with modified 3.7-inch mountain howitzers, yet were rarely issued with the corresponding HE rounds, instead mostly being given smoke.

 

[yulzari1]

I can't imagine a bodge-job like the Charioteer being a thing ITTL. The Charioteer was a desperate attempt to put a big gun into a tank never designed to take it. The OTL Cromwell had a 57.2" turret ring, while even the Valiant here has a 60" ring, and the Victor, entering production year prior to the OTL Cromwell has a 66" turret ring and a 75mm HV gun. The follow-up to this vehicle, the Venom is likely going to come in late 1944 or early 1945 (similar timeframe to the OTL Comet) and will be equipped with a 95mm gun.

Not sure what final production figures are going to be live, but I'd be surprised if it was less than 6,000.

The Charioteer had an enlarged turret ring of IIRC 60” which allowed not only the 84mm 20 Pounder but also was trialled with the 105mm L7 which worked. The Jordanians improved it with stronger traverse motors and fitted a 0,5” Browning but it was never a tank but rather a turreted anti tank gun. A better Archer. Criticised for a thinly armoured tall turret of poor depression (the hull could not drop the breech low enough) but in use it was found easy to hide in a full hull down position as only the turret was exposed which could be easily camouflaged in a prepared positioned. Useful for many years where the light weight and narrow width allowed it to use forest tracks and light bridges unsuitable for Centurions and the like. Still around here and there in the Middle East where it’s mobility allows a quite powerful gun to be brought to difficult places. The addition of the 0,5” Browning was to allow the Charioteer to approach built up areas by suppressing fire from upper floors. The same reason Lebanese 75mm Staghound armoured cars stayed in use and were fitted with the 0,5” Browning on top.

 

[vizzer]

See above. The early CS tanks were armed with modified 3.7-inch mountain howitzers, yet were rarely issued with the corresponding HE rounds, instead mostly being given smoke.

And frequently not even smoke rounds ☹️

 

[ArtosStark]

That wouldn't have been too bad if the CS tanks hadn't been almost completely derived of HE as well. CS tanks with HE would have helped in a few places, especially if they'd had enough of them (they didn't though, usually).

CS tanks had a howitzer intended for high angle fire with a very short barrel. That’s how they fit a much higher calibre in the same turret. The low velocity round would not have been able to hit a specific target at anything over point blank range.

And yet, they still moved to the 75mm when given the chance.

No, they added in the 75. The 6 pounder remained in more British tanks (ignoring the Sherman swarm which was as much about production as effective use). And obviously you prefer a larger gun. It had similar AT while also having better HE. If the 77 mm or 17 pounder had been available at the time, they would have gone for that too.

 

[Cryhavoc101]

Not many. As mentioned the 2 pounder HE shell would have been effectively useless against AT guns. Experiments in WW2 with the 40 mm mortar (with a considerably larger amount of HE than the 2 pounder shell had) found them to be of extremely limited effectiveness against AT guns. Even heavy bombardment by artillery often did not knock out all AT guns in a battery under fire.

The 6 pounder was introduced in combat in May 1942 as an AT gun. A little later as a tank gun. By November 1942 Churchill’s were happily, and effectively using HE in the mountains of Tunisia. Where fights took place at shorter ranges anyway, the HE shell could be effective.

Once there was a gun that could make use of HE, HE was issued. Now if they could have mounted an automatic, as Allen did with the Pom-Pom, things may well have been different. But as it was…

On British 2 pounder HE

I recall years ago reading about the issues of producing enough 2 pounder ammo for the needs of the rapidly expanding British army - initially it was a single munitions factory that was stretched making enough AP ammo let alone additional HE rounds.

The rest of the British ammo production for example artillery and AAA stuff was hoovering up extra capacity.

And at the end of the day as you say the explosive content of these 37mm and 40mm weapons was less than a hand grenade

Once British and US production is ramped up then we start seeing 37mm and 2 pounder HE ammunition but not before 1942

And this was in addition to 'doctrinal' reasons to not have HE