Why didn't the US standardize the T23E3?

Thats not true, the M26 Pershing did for example suffer from a series of very serious reliability issues when it was first introduced in 1945, and they weren't probably ironed out until late 46. In 1945 reliability was even worse than that of the German Tiger II.

 

So 300 saw service during the last 4 months of the war. (?)

50,000 and those were in every theatre of the war. So I think my statement is quite true: "The Allies found something that worked and made a jillion of them...."

 

The initial reliability questions stemmed from what was "new" on the Pershing, While people see the name "Ford" and think that the engine was the same as those used in the Sherman, it wasn't really. It had been completely redesigned to lower its profile and fit in a smaller engine compartment (height-wise), while producing the same horsepower. The new Ford GAF did this, but at the expense of some of the "bulletproof" construction of the GAA versions.

The Torquematic transmission also was problematic at first, but soon put right when deployed into combat conditions. I believe it was something to do with the cooling of the oil for the automatic tranny which hurt this unit's dependability. I'll do some more searching around, but those are the things I recall being at the core of the M26's problems.

 

The US was also rather concerned about keeping up a continuous flow of vehicles. Changes were designed and scheduled so as to minimize any impact on production. I suspect there were enough novel things in this design that that was also a concern.

 

Was it? I'd like to see the numbers and how they were determined. I seriously doubt it was less reliable on a per mileage basis. Perhaps on a per vehicle basis but even that is an open question.

In any case the Pershing was rushed to Europe to get some combat experiance with it. It's use there was more of a test and propaganda mission that a full scale deployment.

 

I believe the reliability flaws were in comparison to the M4, which was superb in that field. The M26 Pershing did incorporate new "novel" (to American production) things, where the M4 was an evolutionary rather than revolutionary tank. The new Pershing had a rear drive sprocket design which lowered overall height since the drive shaft from the engine in the rear didn't have to go through the crew cabin and under the turret basket to the front drive sprocket. That wasn't a problem when it was first designed since it was using a radial aircraft engine and that made it a "tall" tank anyway.

One thing I'll never understand was our (America) sending an example of the M26 to the Soviet Union in one of our last L/L shipments. Sort of like; "OK guys, this is where we are going next. Check it out and find it's flaws"! Dumb as a box of hair to my mind.

 

Well they had sent us copies of theirs. Probably a part of some agreement or someone just following orders. You know "help the Soviets all you can they are our allies" and someone just forgot to tell him/them or "the war is almost over and they may not be our best friends afterwards".

 

I don't think the Soviets needed any help designing and producing effective tanks!

 

Actually the M-26 greatly outclassed the T-34/85 and the Soviets had a hard time developing it's follow on the T-54. Korean War encounters bear this out.

Brndirt1 wrote:

How true. Especially since the Pershing was our most advanced tank at the time and by 1950 we'd be fighting Soviet proxys using Soviet arms and tactics.

 

Was it? I know we had a number of other experimantal designs but in many ways wasn't the Walker Buldog a better tank? Different class but ...

That brings up the question (demonstrating my ignorance again) just how significant where the changes that resulted in the model number change of the Pershing?

 

I'm not claiming to be any expert, brndirt1 seems to really know this stuff in and out, but I'll give a reply on what I do know and from what sources I have handy.
Development of the M-41 (T37) started well after WWII, in 1947, as a replacement for the light tank, M-24 Chaffee. Production didn't start until 1951. I didn't consider it because it was developed post-war. From what I've read it had a number of issues that weren't worked out until after it was fielded and it only saw limited use during the latter stages of the Korean War.

What number change in particular are you asking about on the Pershing? The T23E3 was a medium tank prototype and was never standardized, although the turret was used on the M4A1 and M4A3 76mm Shermans. The Pershing was developed as a heavy tank from the T26 series prototypes. It was standardized as the M-26. In 1948, new, more powerful engine, new transmission, redesigned armored rear deck, addition of a muzzle brake and bore excavator (M3 90mm gun to M3A1) and a new telescope resulted in the M26E2, redesignated T40 and standardized as M-46 Patton. The M26/M46 hull mated to a new improved turret resulted in the M47 (T42). The M47/M41 were developed concurrently and designed to use many of the same parts, so in this respect it was similar to the Pershing.

 

Confusion on my part I meant the M-24 not the M-41. It does make it clear that I'm far from an expert.

The M-26 to M-46 one.

My understanding was the T26 line were developed as medium tanks and that the Pershing was rerated a heavy mostly for propaganda purposes. There T28 and T29 (?) were the heavy tank lines I believe.

 

lwd wrote:

Good question my friend. I don't believe that the Pershing was rated as a heavy tank because of propoganda reasons. The reason it was rated as a heavy tank was due to it's gun size, weight and intended role. It was rerated as a medium tank in 1950 when the US Ordinance Committee changed the classification of light, medium and heavy tanks to 76mm and less=light tank, 90mm medium and 120mm heavy. The T29 and T30 were heavy tank designs intended to counter the 70ton TigerII based on a modified M26 chassis. The T28 was a super heavy tank design (whatever that designation means). The medium tank designs, post M4 were T20,T22,T23 (all 75 and 76mm gunned tanks) and the T25 which was a T23 with a 90mm gun turret. The T26 which became the M26 was similar to the T25 but with the glacis plate increased to 4 in (100 mm) of armor.

The M-24 was a very good light tank but of older tchnology than the M26. It still used the rear engine, front transmission, front drive sprocket design where the drive train ran through the hull. It did incorporate a new lightweight 75mm gun (as opposed to a 37mm on the M3/M5) and a torsion bar suspension that decreased height somewhat and gave improved cross-country performance. It was very much inferior to the T34/85, a medium tank, because the M-26 was a light tank, more lightly armed and armored. The M-24's initially sent to Korea were decimated by the T34.

The M-46 was actually a remanufactured M-26 hull with uprated engines and transmissions.
M26E2=Continental AV-1790-1 engine (810hp up from 500 Hp) Allison CD 850-1 cross-drive transmission.
T40=was the M26 upgrade to M46 test bed 10 vehicles modified, Continental AV-1790-3 engine and Allison CD 850-2 cross-drive transmission.
M46=Continental AV-1790-5 engine and Allison CD 850-3 cross-drive transmission.
Other changes were a modified, armored grill, mufflers moved to the fenders, square transmission access plates on the rear hull, M3A1 vs M3 90mm gun (addition of muzzle brake and bore excavator) and M83 telescopic sight.

 

I think this is incorrect, from what I've read the decision to send the M26 to Okinawa was made in May '45, 12 M26E3's were shipped 31May45 and didn't arrive until 21July, after fighting ended. I'm careful with what I use from Wikipedia but they state; "the tanks were not completely offloaded on the beach at Naha, Okinawa until August 4, 1945."

 

Wikpedia quotes R. P. Hunnicutt's "Pershing : A History of the Medium Tank T-20 Series". I looked up the article you referred to and in the footnotes listed Hunnicutt's book (which I have) .I then look at the pages it referred to and it seems Wikpedia does have it right in this regard. Hunnicutt is an extremely good reference for US tanks/AFV's almost to being the "Bible".

 

I think that rather than introduce a new tank such as the T-23, with its many new components that would impact training and supply, improving the gun would have been better. The 76mm was often not powerful enough to defeat the armour of the Panther and Tigers in normal combat. Producing the 17 pounder and its special ammunition in the US, or adopting the proposal to place the T-26 turret with its 90mm gun on the M-4 chassis might have made more sense. This would have meant another headache for Supply, though. Also tank versus tank combat became rarer after Normandy so the M-4 was good enough in most circumstances. Except for special circumstances like the Battle of the Bulge, generally, US tanks were killed by anti-tank guns and hand held anti-tank weapons. (and the big killer, mines) Wet stowage for ammunition helped and better understanding and discipline in stowing combustibles inside the hull might have made M-4s less fire traps. Producing more M-4A3E2s with it's thicker armour (and with a better gun) might have saved lives but would also have wore out engines, transmissions, tracks and suspension components faster.

Best wishes,
Grant

 

Thanks for verifying the Wiki info. I agree, Hunnicutt is an excellent source and have several of his books.

 

Wasn't Patton personally against the deployment of the Pershing, and in fact was instrumental in delaying it's introduction? When the German offensive commenced with all their heavy tank units on 16 Dec 44, about 20 or so Pershings were rushed to Europe, and off-loaded at Antwerp. They didn't see action until late February (probably the ones that Clint's uncle saw). Patton was happy with the Shermans I believe, and that view supports Brad's statement as well.

Also, the US Army still clung to it's tank destroyer doctrine state of mind, and was slow to get out of this line of thinking until the Battle of the Bulge so rudely awakened them. Just my opinion of course.

 

There are two main reasons why the T23 didn't get introduced:

1. There were technical and design issues that were not worth the effort. The electric drive transmission was complicated and expensive to produce. It had been selected because of its tactical properties. The T23 could zero turn in its own length, the driver had "finger-tip control" of the tank. It had good smooth acceleration all the way to 35 mph.
Complicating this was the retention of the VVS suspension of the Sherman. This suspension was really not acceptable for a vehicle capable of 30+ mph.
The T23 76mm gun turret was retained on this vehicle giving it no more protection or firepower than a standard sherman. The hull was better designed and had somewhat more armor (the glacis was 3" thick and 5.1" with slope making it almost equal to a Panther).

2. Other designs contemporary with the T23 were simply alot better vehicles. There was no justification for introducing a marginally better tank rather than a much better one.
I personally think the T25E1 would have been a better choice than the T26/M26. This vehicle has the same armor as the T23 but mounts the turret the M26 had. It has torsion bar suspension and a torquematic rear drive transmission. In armor, mobility and, firepower it is essentially a US Panther tank. Given that procurement could have begun in June 43 and issue to troops by June 44 this tank would have been a real game changer. But, better being the enemy of good enough the US Army went for the inproved version of this tank, the M26. The only real advantage the M26 had over the T25 was thicker armor that added about 7 tons to the weight and cut the top speed down to about 20 mph.

 

Yes, one of my guru's stepped in! I was hoping for a reply from you or brndirt1 to give us a definitive opinion. One question though, wasn't the T-26's 90mm gun also an advantage over the 76mm on the T-25? I agree the original M26, with the same engine Ford GAF engine as the later Shermans, suffered from being underpowered and didn't come into it's own until the post-war upgrade to the Continental AV-1790 series engine, gave it an acceptable power to weight ratio. Thanks again for the intell.