Pre Ww2 Tanks

[Ken Estes]

???

 

The US had no equivalent of the PAK 75, to my knowledge. Even if that were the case, Rich's research for his new book shows the US projectiles fell far short of equivalent performance.

[bojan]

Pack, iow 75mm M1 howitzer.

[shootER5]

Pack, iow 75mm M1 howitzer.

 

Si.

 

 

[DougRichards]

 

Pack, iow 75mm M1 howitzer.

 

Si.

 

 

 

 

 

 

That is a lot of vehicle for not a lot of gun. But the genesis of the M7 can be seen , but even comparing the M7 to the Wespe, the HMC M7 was also a lot of vehicle for the 105mm howitzer.

 

If the US had entered the war a year earlier then this combination may have gone to war and probably would have given a good account of itself..(invasion of France 1942 anyone?)

 

Meanwhile other vehicles armed with either the 75mm howitzer, or a derivative, served usefully on many fronts, from the HMC M8 to the LVT(a)5 to the lesser known HMC T30 on the M3 half track.

 

It was a good gun, its shell being the same as that used by the range of 75mm guns mounted on US tanks and other SP mountings, of course with a different cartridge case. But there is also the (perhaps apocryphal) story of the Marine M4 unit that ran out of ammunition for their 75mm tank guns and used M1 Howitzer ammunition in its place. Of course much lower MV but the bang on target at close range against Japanese bunkers would not have been much diminished.

 

What surprises me about the 75mm on the Char Bis was the thickness of the barrel, almost as if the gun itself was armoured. Perhaps as the gun was so short the thickness of the barrel was required for strength to enable the sell to be discharged at what could have been a useful MV.

Edited July 31, 2019 by DougRichards

[Rich]

 

It should also be remembered that the main AT weapon of the M3 medium was originally the 37mm in the turret. At first it was proposed mounting a version of the Pack 75 in the sponsor, that would have been really an HE / Smoke weapon only, and only later was the longer 75mm accepted as being useful in the AT role and put in the sponsor.

 

Wasn't the T5E not more than a proof of concept verhicle, leading to the M3 design ?

 

 

The Medium Tank T5E2 was actually the T5 Phase III pilot with a new superstructure. Chief of Infantry MG George A. Lynch requested Ordnance test the pilot with a 75mm as main armament based on MID reports of European tanks with such a weapon mounted. Ordnance sketched out such a vehicle on 27 January 1939 using the 75mm Howitzer M1A1, because there was no suitable 75mm gun at the time.

 

In that sense it could be termed "proof of concept", but there was little doubt it could work. However, the idea of modifying the standardized T5 Phase III, the Medium Tank M2A1, as the Medium Tank M3, with a 75mm gun, developed between 5 and 13 June 1940, when MG Lynch sent Ordnance his analysis of future tank developments based on upon the initial MID reports from the French Campaign. Ordnance determined that a turreted 75mm gun was outside the capability of the current state of the art in the U.S., so chose to adapt the M2A1 as the interim Medium Tank M3.

[Rich]

 

 

Pack, iow 75mm M1 howitzer.

 

Si.

 

 

That is a lot of vehicle for not a lot of gun. But the genesis of the M7 can be seen , but even comparing the M7 to the Wespe, the HMC M7 was also a lot of vehicle for the 105mm howitzer.

 

If the US had entered the war a year earlier then this combination may have gone to war and probably would have given a good account of itself..(invasion of France 1942 anyone?)

 

Meanwhile other vehicles armed with either the 75mm howitzer, or a derivative, served usefully on many fronts, from the HMC M8 to the LVT(a)5 to the lesser known HMC T30 on the M3 half track.

 

It was a good gun, its shell being the same as that used by the range of 75mm guns mounted on US tanks and other SP mountings, of course with a different cartridge case. But there is also the (perhaps apocryphal) story of the Marine M4 unit that ran out of ammunition for their 75mm tank guns and used M1 Howitzer ammunition in its place. Of course much lower MV but the bang on target at close range against Japanese bunkers would not have been much diminished.

 

 

The Medium Tank T5E2 was never intended as a production vehicle. Instead, in every sense of the word, it was a pilot model. As I mentioned, it used the 75mm M1A1 Howitzer only because it was available and could be made to work...the 75mm Gun M1897, the only alternative, was simply not suitable for mounting in the sponson of the T5E2. Instead, between June 1940 and July 1941 the 75mm Gun T6 (the last iteration of a failed AA design) was adapted as a tank gun.

[Ken Estes]

Duh, thanks all.

[DougRichards]

Well the US M1 75mm howitzer was roughly the equivalent, when vehicle mounted, to the 7.5cm KwK 37. The German gun's shell was a little heavier, but essentially very similar specs. It could be considered that the HMC M8 filled the same niche that as the Panzer III Ausf. N, remembering that the M4 was getting 105mm howitzers for the same role.

[DougRichards]

We need a thread: US AFVs if the USA entered the war in December 1940 instead of 1941.........

[Paul Lakowski]

Most bunkers -on both side of the French-German boarder- were designed to withstand direct fire from heavier field artillery, with concrete thickness of 1.5m or more.

 

Where these 3" guns really expected to destroy WESTWALL fortifications with that thickness .

 

Were they just for lighter tactical field bunkers, with concrete thickness of 3/4 meter or less ?

[Markus Becker]

Depends where you hit them. A random 250 kilo bomb/8" shell is unlikely to score a direct hit in the first place and even less likely to hit a firing port. An M10 might have been able to 'snipe' firing ports.

[rmgill]

We need a thread: US AFVs if the USA entered the war in December 1940 instead of 1941.........

 

Ughh.

 

[DougRichards]

Depends where you hit them. A random 250 kilo bomb/8" shell is unlikely to score a direct hit in the first place and even less likely to hit a firing port. An M10 might have been able to 'snipe' firing ports.

 

But the GMC M12 was useful for that sort of work, firing 155mm AP shells, originally designed for coastal defense, penetrating two metres of concrete at 2000 metres in the direct fire role.

Edited August 2, 2019 by DougRichards

[DKTanker]

Most bunkers -on both side of the French-German boarder- were designed to withstand direct fire from heavier field artillery, with concrete thickness of 1.5m or more.

 

Where these 3" guns really expected to destroy WESTWALL fortifications with that thickness .

 

Were they just for lighter tactical field bunkers, with concrete thickness of 3/4 meter or less ?

Nobody else asked so I will. Where have you been keeping yourself, Stranger?

[Walter_Sobchak]

Most bunkers -on both side of the French-German boarder- were designed to withstand direct fire from heavier field artillery, with concrete thickness of 1.5m or more.

 

Where these 3" guns really expected to destroy WESTWALL fortifications with that thickness .

 

Were they just for lighter tactical field bunkers, with concrete thickness of 3/4 meter or less ?

 

Wiki makes the claim that the 75mm on the Char B1 bis was mounted as low as possible on the hull to make it easier to shoot into vision and gun slits on enemy bunkers. No idea if that's actually true.

[DogDodger]

Wiki makes the claim that the 75mm on the Char B1 bis was mounted as low as possible on the hull to make it easier to shoot into vision and gun slits on enemy bunkers. No idea if that's actually true.

Vauvillier makes a similar assertion, FWIW...

[Ken Estes]

The French pre-war designs for their superheavy tanks were expected to use their 90mm guns to snipe at the embrasures of the West Wall, Paul. However the British TOG's 3-inch gun was only supposed to overcome field fortifications. The 1944 designs for UK Tortoise and US T28 were aimed at penetrating fortress armor, but they of course knew little about the West Wall bunker design.

 

+1 to DKTanker's comment, how are you these days Paul?

Edited August 3, 2019 by Ken Estes