American purchase programs, alternatives and reality, 1937-43

[marathag]

Chrysler flathead six, times five, should be reliable if the gear train is.

It seems to have been a reliable lump of iron, and was a 'power egg' of sorts

since there was no way to really work on it inside the tank, had to be lifted out for any work

 

[ThomasP]

I have come across a couple of different sources that said the A-57 was the most reliable of the 4 major types fitted to the Lee/Grant and Sherman - at least until reliability issues with the Ford GAA were worked out - but it also required a bit more routine maintenance.

 

[Frog]

The Chrysler powered M4A4 was favored by the British for the Firefly conversion because of it longer engine compartment that helped to counterbalance the gun barrel weight.

 

[EwenS]

The Chrysler powered M4A4 was favored by the British for the Firefly conversion because of it longer engine compartment that helped to counterbalance the gun barrel weight.

No.

The earliest conversion were from the M4A4 because it was the version with the greatest population in Britain in late 1943 when work began. Shermans for Firefly conversion had to have certain features (wide mantle, petrol engine, hydraulic turret traverse and M34A1 gun mounting) before conversion could even be considered. When they ran short of suitable M4A4 attention turned to M4 Sherman I hulls with those features.

This is the tank census for Britain in June 1944

21st Army Group Tank Strengths - June 1944

By mid-1944, conversions were being carried out in numbers on the short M4 Sherman I chassis, both from vehicles with fully welded hulls and those with composite or hybrid hulls (cast front section & welded rear section). These were turning up in Normandy by mid-July 1944. By the beginning of 1945 Sherman IC outnumbered Sherman VC about 2 to 1 in 21st Army Group.

There were differences in internal layout between the two versions regarding the ammunition bins.

The M4A4 Sherman V tanks were also in demand in 1943/44 for conversion to Crab Flail Tanks due to the greater power of the Chrysler Multibank engine v the other engine options.

 

[marathag]

The M4A4 Sherman V tanks were also in demand in 1943/44 for conversion to Crab Flail Tanks due to the greater power of the Chrysler Multibank engine v the other engine options.

On paper, the GAA had 500HP and 1040 ft-lbs of torque, vs 425HP and 1060 ft-lbs of torque.
The difference was, the Multibank torque peak was at 1400 rpm, compared to the Ford that came in at the far higher 2200rpm

So the Chrysler had more usable power at lower rpms.
that 4000 pound of extra cast iron block at the rear helped balance out that Crab as well

 

[BobB]

There was no second source of P-38s in 1940, 1941, 1942, 1943, 1944, and the best part of the war of 1945. So I'd say that, as far as the P-38 program is concerned, there was no actual second source.



Vitally important? As decided by whom?

First Vultee P-38 delivery was in January 1945. The Vengeance wasn't a world beater like the P-39 but it was doing the job in Burma when nothing else was available.

 

[tomo pauk]

First Vultee P-38 delivery was in January 1945.

Thank you.

The Vengeance wasn't a world beater like the P-39 but it was doing the job in Burma when nothing else was available.

I guess you mean '38' there, not '39.
1943 was not 1942. By Spring of 1943, Allied have had a lot of aircraft available. Even in Burma, for what was for the Allies in aggregate listed as perhaps as 3rd if not a 4th priority (no attempt to downplay the sacrifices of the men serving there) among the theaters of war - after the Eastern front, North Atlantic, ETO, MTO, SW Pacific.
In the same time, the P-38 fighter groups were not available for the ETO to protect the US bombers in a war theatre that was the 1st on the list of priorities for the UK and USA, since there was not enough of P-38s back then.

 

[BobB]

Thank you.


I guess you mean '38' there, not '39.
1943 was not 1942. By Spring of 1943, Allied have had a lot of aircraft available. Even in Burma, for what was for the Allies in aggregate listed as perhaps as 3rd if not a 4th priority (no attempt to downplay the sacrifices of the men serving there) among the theaters of war - after the Eastern front, North Atlantic, ETO, MTO, SW Pacific.
In the same time, the P-38 fighter groups were not available for the ETO to protect the US bombers in a war theatre that was the 1st on the list of priorities for the UK and USA, since there was not enough of P-38s back then.

The P-39 was a world beater. I read that on an internet forum so I know it's true. I'm serious, and don't call me Shirley. A lot of the Vultee P-38's went to Panama because they wanted to replace the single engine fighters based there but other priorities delayed that until 1945.