AHC: Get US To Adopt Centurion Tank Post-WWII

[spkaca]

The challenge did say that it could be in service with Army or Marines. The USMC used/ still uses the Harrier - I wonder if that is at least partly to differentiate themselves from the Army/ Navy.
So (assuming this is part of the motivation) perhaps something similar could happen, with the Marines deciding to use the Centurion after an especially sharp bout of inter-service rivalry with the Army. In fact the USMC did face an existential crisis in 1945-7 with elements in the Army pushing for its abolition (following the postwar budget cuts), according to Wikipedia. So perhaps that could have been the catalyst.

 

[Petike]

I was literally about to post 'And somewhere, for some unknown reason, Mac suddenly started grinning'.

Or pumping his fist in the air.

 

[MalcontentRex]

Slight tangent here, but I'm curious as to why it was concluded that the 20 Pounder (84mm) was deemed inadequate against the T-54. The 20lber had nearly the power of the PaK/KwK43 and, with its better ammunition, had actually more penetration. I can't see the D10/BS3 matching it (of course, explosive power for antipersonnel use or shaped charges is another story).

 

[Cryhavoc101]

Nice timeline but I take issue with calling the T-54/55 "brand new" for 1957 when they'd been in service since 1946...

True but the West didnt get a good look at one until 1956 and this drove the need for the L7 105mm gun.

 

[Cryhavoc101]

Slight tangent here, but I'm curious as to why it was concluded that the 20 Pounder (84mm) was deemed inadequate against the T-54. The 20lber had nearly the power of the PaK/KwK43 and, with its better ammunition, had actually more penetration. I can't see the D10/BS3 matching it (of course, explosive power for antipersonnel use or shaped charges is another story).

It wasn't as it turns out!

The gun is a very good hole puncher.

Its just that the West got a good look at the T54 in 1956 (one was driven onto the British Embassy grounds in Hungry allowing them to get a good look at it) and 'concluded' that the 20 pounder would struggle.

From my understanding it was a perception rather than hard experiance or science etc

That and the 100mm gun on the T54/55 took away any range advantage that the 20 pounder armed tanks had over it.

 

[riggerrob]

... One question, do the Americans take to the idea of the BV for making drinks and heating rations, and if so, does this bit of equipment make it into subsequent armoured vehicles?"

...................................................................................................
Boiling vessel makes perfect sense if you have to sit in the vehicle all day. Heating canned beans on the exhaust manifold gets tiresome, quickly. Later marks would have micro-wave ovens.

 

[riggerrob]

US Army would have been wise to adopt Centurions in 1945.
circa 1945, the British 17-pounder was the best WALLY anti-tank gun.
During the 1960s, the British 105 mm L7 was the best anti-tank gun.
During the 1970s, the British 120 mm was the best anti-tank gun available.

However, the Centurion would have seriously benefitted from an American diesel engine. The Rolls Royce Meteor engine installed in early Centurions had a brilliance power-to-weight ratio, but was a bitch to maintain. Since it was derived from the aircraft RR Merlin engine, it had two spark plugs per cylinder. Changing spark plugs on aircraft engines was easy once you removed all the cowlings (a 10 minute job), but a bitch deep in an AFV hull.
Also consider that most of the Centurions that were later upgraded (Israel etc.) were converted to diesel engines.
I vote for an American diesel engine.

 

[Riain]

IIUC the diesel version of the AV1790 didn't appear until 1960 with the initial M60, and in 1963 with upgraded M48A3s. Throughout the 50s M48s had 810hp petrol engines, a good deal more than the 650hp of the meteor.

So what diesel engine would the US put in Centurions if they got some in the 50s?

 

[marathag]

circa 1945, the British 17-pounder was the best WALLY anti-tank gun.
During the 1960s, the British 105 mm L7 was the best anti-tank gun.
During the 1970s, the British 120 mm was the best anti-tank gun available.

17 pdr 130mm for 1000 yards

17 pdr 192mm for 1000 yards APDS

32 pdr 117mm@30 for 1000 yards

US M3 used in the Pershing, 122mm@30 for 1000 yards

US M3 used in the Pershing, 199mm@30 for 1000 yards

US T15E2, used in the Super Pershing, 127mm@30 for 1000 yards

US T15E2, used in the Super Pershing, 221mm@30 for 1000 yards HVAP.

Postwar

20 pdr 225mm@30 for 1000 yards APDS

90mm T119 152mm@30 for 1000 yards

90mm T119 249mm@30 for 1000 yards HVAP

Soviet 100mm AP 143mm@1000m

Soviet 100mm HV 173mm@2000m

M68/L7 105mm M392 APDS 250mm for 2000m

M68/L7 105mm M735 APFSDS 375mm for 2000m (1970s)

L11 120mm L15 340mm for 2000m (1960s)

 

[MalcontentRex]

I'm under the impression that Soviet tank/AT guns were always somewhat inferior to Western/Nazi guns of equivalent bore due to poorer metallurgy and so needed to be bigger for same penetration (i.e. Soviet 76mm was equal to or slightly inferior to the US 75mm in penetration, the 85mm was equal to or slightly inferior to the 76mm, etc.) and this was not fully rectified until postwar. In fact isn't even the standard Pershing 90mm pretty much equal to the 122mm on the JS series?

Of course explosive power strongly went the way of the Soviets with those far more massive shells.

 

[Cryhavoc101]

I'm under the impression that Soviet tank/AT guns were always somewhat inferior to Western/Nazi guns of equivalent bore due to poorer metallurgy and so needed to be bigger for same penetration (i.e. Soviet 76mm was equal to or slightly inferior to the US 75mm in penetration, the 85mm was equal to or slightly inferior to the 76mm, etc.) and this was not fully rectified until postwar. In fact isn't even the standard Pershing 90mm pretty much equal to the 122mm on the JS series?

Of course explosive power strongly went the way of the Soviets with those far more massive shells.

I always understood the 122mm's benefit was the more effective HE shell - I seem to recall that the 85mm was a better hole puncher!

 

[MalcontentRex]

I always understood the 122mm's benefit was the more effective HE shell - I seem to recall that the 85mm was a better hole puncher!

That seems like a bit of a stretch. I think the US standard 90mm (not the long 90), the Soviet D-25 122mm, the D-10/BS3, and the 17 Pounder were fairly equivalent for penetration (the 100mm was probably the best, but not by a huge margin) and that the U.S. 76mm/3", the Soviet 85mm, and the British 77mm were all pretty equivalent as well. I recall reading in "Was The King Tiger Really King?" over on Valera Potapov's site that the U.S. 76mm was superior in penetration to the 85 (due of course to quality of alloying).

If you could manufacture 76mm and 85mm AP shells with the exact same quality of metal, then naturally the 85 would be superior, but that was not done until postwar, I'm fairly sure.

 

[Vjacheslav Malyshev]

I always understood the 122mm's benefit was the more effective HE shell - I seem to recall that the 85mm was a better hole puncher!

The 122mm was had much better AT performance than either the 85mm or 76mm.

US Army would have been wise to adopt Centurions in 1945.
circa 1945, the British 17-pounder was the best WALLY anti-tank gun.

The US 76mm was better seeing as it could actually hit something.

I'm under the impression that Soviet tank/AT guns were always somewhat inferior to Western/Nazi guns of equivalent bore due to poorer metallurgy and so needed to be bigger for same penetration (i.e. Soviet 76mm was equal to or slightly inferior to the US 75mm in penetration, the 85mm was equal to or slightly inferior to the 76mm, etc.) and this was not fully rectified until postwar. In fact isn't even the standard Pershing 90mm pretty much equal to the 122mm on the JS series?

Of course explosive power strongly went the way of the Soviets with those far more massive shells.

Yeah the D-10T is straight up more powerful than a L7 however due to superior barrel and ammo manufacture the L7 has better penetration.

 

[MattII]

The US 76mm was better seeing as it could actually hit something.

So could the 17-pounders, like 5 panthers in 6 shots, at combat ranges, and that from a firefly, which wasn't a particularly great tank to be a gunner in. That record was scored by Lt G. K. Henry and trooper A. Chapman, 1st Hussars, on 9 June, while defending Norrey-en-Bessin. this was topped five days later on 14 june, when Sgt. Harris and trooper Mackillop of 4th/7th Dragoon Guards knocked out 5 Panthers for 5 shots, while defending Lingèvres, at least 2 shots taken from over 750m.

 

[Vjacheslav Malyshev]

So could the 17-pounders, like 5 panthers in 6 shots, at combat ranges, and that from a firefly, which wasn't a particularly great tank to be a gunner in. That record was scored by Lt G. K. Henry and trooper A. Chapman, 1st Hussars, on 9 June, while defending Norrey-en-Bessin. this was topped five days later on 14 june, when Sgt. Harris and trooper Mackillop of 4th/7th Dragoon Guards knocked out 5 Panthers for 5 shots, while defending Lingèvres, at least 2 shots taken from over 750m.

The 76mm and 90mm are more accurate than the 17 pounder, also 17 pounder APDS just could not hit the broad side of a barn.

It was thus concluded that a “comparison of data shows that the 17pounder gun has greater dispersion than either the 90mm gun or the 76mm gun”

At the range to which the 76mm must close in order to go through the Panther's lower glacis, SVDS is rated at about 14% chance to hit a 5'x2'target. The same report gives 76mm APC (Reputedly not as accurate as HVAP) a 96% chance to hit the same sized target, which also happens to be about the size of the turret. Which the 76mm tank may as well aim for instead at a longer range anyway. Where is the practical advantage to the capability to puch through at extended range if you can't get the shell to hit to begin with? By the time Firefly gets close enough to hit the target, 76mm would be punching through as well anyway.

 

[MattII]

Frontal armour of a panther at combat ranges, repeatedly, shows that the APCBC had plenty of punch, and was usably accurate. You can claim all the tests you like, but 5/5 and 6/5 on two separate occasions at combat ranges shows it was a perfectly good vehicle, despite numerous ergonomic issues regarding shoehorning that gun into a turret really to small for it, which probably accounts for the inaccuracies during testing. In addition, this testing was carried out in late 43-early 44, ie, during testing and before production had started, so also before most of the crews were trained.

 

[LostCosmonaut]

Frontal armour of a panther at 800m, repeatedly, shows that the APCBC had plenty of punch, and was usably accurate. You can claim all the tests you like, but 5/5 and 6/5 on two separate occasions at combat ranges shows it was a perfectly good vehicle, despite numerous ergonomic issues.

Today I learned anecdotes trump scientific tests done under controlled conditions. Who knew?

 

[MattII]

Anecdotes by trained crews in battlefield conditions trumps pre-production testing by partly trained crews. But hey, feel free to disregard training and experience to try to make a point, I mean it's not like that stuff makes an actual difference right? Of course, it was probably still less accurate than the 76mm, but hey, when you can smack the enemy tank no matter where you hit at a decent range, then accuracy doesn't really matter that much.

 

[Cryhavoc101]

The 122mm was had much better AT performance than either the 85mm or 76mm.

Ahh so it does - there was some reason that the 85mm was prefered but I cannot recall what it was!

The US 76mm was better seeing as it could actually hit something.

Your going to need to quantify that mate - the main critism of the 17 pounder came as I understand it from the Aberdeen tests in early 1944 which to my cynical mind where trying to defend the choice of up gunning the Shermans to 76mm and not adopting either the 17 pounder or 90mm - all this against increasing scrutiny / Critique from Congress and the Press.

Indeed the British Army seemed to have few problems hitting stuff with it in the field!

 

[Vjacheslav Malyshev]

They did testing of both the 122mm and 85mm in early T-44 prototypes. They went with the 85mm mainly due to the impracticality of the single piece 122mm ammunition.