M1 Abrams vs Challenger 2 vs Leopard 2 vs Leclerc

[Harkonnen]

About reliability.

[Harkonnen]

1 Full video of 2023 Leo-2 without drivers hatch -

2 And another one -

Actully there are more but no need to post

[alejandro_]

14 minutes ago, Harkonnen said:

About reliability.

This seems very low, but there is no context or definition of  reliability.  In 1970 T-64s carried out an exercise involving a 900km march, which they covered within 3 days. Out of 330 tanks 22 fell behind, but they caught up during river crossings.

http://andrei-bt.livejournal.com/59590.html

[Harkonnen]

16 minutes ago, alejandro_ said:

This seems very low, but there is no context or definition of  reliability.  In 1970 T-64s carried out an exercise involving a 900km march, which they covered within 3 days. Out of 330 tanks 22 fell behind, but they caught up during river crossings.

http://andrei-bt.livejournal.com/59590.html

Context is exercises service in BAOR and other units.  

Edited March 22 by Harkonnen

[Stuart Galbraith]

What is the date for that?

[Harkonnen]

2 hours ago, Stuart Galbraith said:

What is the date for that?

1991

[Harkonnen]

British Archives. About reliability (see Pt. 1 https://twitter.com/AndreiBtvt/status/1771251615955128523). The resource of a number of assemblies of the Challenger tank can be compared with the T-64A(B), T-72, T-80 tanks according to the data from the article RESULTS OF SUBCONTROLLED EXPERIENCE OF TANKS  http://btvt.info/5library/vot_nadeznost_64_72_80.htm

[Stuart Galbraith]

Im not sure why Challenger 2 is so different. It wasnt automotively that different, the engine had a few more electronic components on it, but was still a CV12. It had new gear ratios, but it was related to the previous gearbox. The suspension was the same. Ok, it had 2 pin track, which surely cant make that much difference.

You are left with my conclusion, that either someone was deliberately overstating the reliablity of Challenger 2, or understating the reliablity of Challenger 1, or conceivably even both. Without knowing whom this document was to be sent against, its impossible to gauge the likelihood of that. But it seems odd that there is such a disparity. Im not sure what would account for it, considering Challenger 2 was heavier.

The only other conclusion I can make is they are factoring the reliablity of the armament, fire control and thermal gear, whcih was a generation on from Challenger 1. But that would not of course, necessarily stop it completing a road march.

Im reminded of an occasion when the RAF made a case for cancelling the Royal Navy's aircraft carrier back in the 1960's, by showing the range of RAF aircraft that could cover most of the South China sea area. To do it, they had to shrink the size of the map according to the range of the aircraft. Its the MOD, its what they do.

[Ssnake]

New Challenger 2 taken fresh from factory in the trials vs a rickety old Challenger 1 taken from a Soltau motor pool? Or, maybe simply uneven production quality (British industry, rightfully or wrong, had a reputation for that), or maybe the factory simply learned a thing or two between when the trial Challenger 1 and the Challenger 2 were made.

[Mistral]

Stuart could be right, armies are like any other large org, and if you don’t know for whom or why this was written you are missing a lot of info.  That’s my issue with written docs, they are almost never written to preserve the truth for posterity but to support an agenda at the time they were written.

[Harkonnen]

Strv122 

 

[old_goat]

4 hours ago, Ssnake said:

New Challenger 2 taken fresh from factory in the trials vs a rickety old Challenger 1 taken from a Soltau motor pool? Or, maybe simply uneven production quality (British industry, rightfully or wrong, had a reputation for that), or maybe the factory simply learned a thing or two between when the trial Challenger 1 and the Challenger 2 were made.

Check the requirements in the second document, they are surprisingly low. Some components are comparable to T-64/72/80, but others are much lower than those. Overall, Challengers are definitely inferior to the mentioned soviet tanks, probably in the same league as the T-55/62.

[methos]

5 hours ago, Stuart Galbraith said:

Im not sure why Challenger 2 is so different. It wasnt automotively that different, the engine had a few more electronic components on it, but was still a CV12. It had new gear ratios, but it was related to the previous gearbox. The suspension was the same. Ok, it had 2 pin track, which surely cant make that much difference.

You are left with my conclusion, that either someone was deliberately overstating the reliablity of Challenger 2, or understating the reliablity of Challenger 1, or conceivably even both. Without knowing whom this document was to be sent against, its impossible to gauge the likelihood of that. But it seems odd that there is such a disparity. Im not sure what would account for it, considering Challenger 2 was heavier.

The only other conclusion I can make is they are factoring the reliablity of the armament, fire control and thermal gear, whcih was a generation on from Challenger 1. But that would not of course, necessarily stop it completing a road march.

Im reminded of an occasion when the RAF made a case for cancelling the Royal Navy's aircraft carrier back in the 1960's, by showing the range of RAF aircraft that could cover most of the South China sea area. To do it, they had to shrink the size of the map according to the range of the aircraft. Its the MOD, its what they do.

Two aspects to take into account:

1. the stated reliably of the CR1 was the result of trials and experiences, the reliability for the CR2 meanwhile was estimated based on prototypes and promises of Vickers to fix the discovered issues

2. the CR2 did not use the same suspension as CR, i.e. it uses an improved, so-called second generation Hydrogas suspension from Horstmann. The CR1 used a first generation system.

[bojan]

43 minutes ago, Harkonnen said:

Strv122

Why are blast doors open? Are they open by default (sounds to me like a bad idea) in case of tank not being powered?

[Stuart Galbraith]

2 hours ago, methos said:

Two aspects to take into account:

1. the stated reliably of the CR1 was the result of trials and experiences, the reliability for the CR2 meanwhile was estimated based on prototypes and promises of Vickers to fix the discovered issues

2. the CR2 did not use the same suspension as CR, i.e. it uses an improved, so-called second generation Hydrogas suspension from Horstmann. The CR1 used a first generation system.

Have you read of it being a major source of failure?I've personally have not.  Not tor the point where it caused a 25 percent difference in availability anyway. That's Chieftain style levels of failure.

Besides, I looked over one of these prototypes in 1994. It was built on a Challenger 1 driver training tank, even retaining the original side plates. I can't be certain they didn't replace the transmission and hydrogas suspension of course, but there was no obvious indication they changed anything but the lighting cluster. I'm dont believe they even build a driving test rig.

[Stuart Galbraith]

6 hours ago, Mistral said:

Stuart could be right, armies are like any other large org, and if you don’t know for whom or why this was written you are missing a lot of info.  That’s my issue with written docs, they are almost never written to preserve the truth for posterity but to support an agenda at the time they were written.

I'm sorry, can I print this out?

The interesting thing for me is how much stock it puts on leopard 2. Probably rightly, but it does make me wonder what the purpose of the document was, because Leopard 2 was off the cards at the start. Imagine what The Sun would say about buying Panzers.

It's an odd document. I'd guess it says more about what tank the Army wanted, than necessary  depicting reality we should accept at face value.

 

 

 

[Stuart Galbraith]

7 hours ago, Ssnake said:

New Challenger 2 taken fresh from factory in the trials vs a rickety old Challenger 1 taken from a Soltau motor pool? Or, maybe simply uneven production quality (British industry, rightfully or wrong, had a reputation for that), or maybe the factory simply learned a thing or two between when the trial Challenger 1 and the Challenger 2 were made.

Well, there wasn't any really, not in 1991. They were just cr1 driver training tanks that must have already racked up miles at Bovington. Presumably reconditioned  I suppose, but I wouldn't put money on it myself.

You aren't wrong about build quality. I know for a fact a conversion kit to convert Fv432s to command vehicles wouldn't fit part of the fleet because internally they were dimensionally different (Friday afternoon ones probably). It certainly happened.

But as these were Challenger 1s, and at least some of the fleet probably retained cr1 components  for at least some time, automotively for me, I can't see where a 25 percent change in availability comes from. Particularly  as the components in the drivetrain must themselves be subject to test and failure. I'd guess the first production tanks weren't even built till 1995 or 1996.

[Ssnake]

6 hours ago, bojan said:

Why are blast doors open? Are they open by default (sounds to me like a bad idea) in case of tank not being powered?

No, they just didn't close them. I suspect it's due to the loss of electric power, and they didn't bother to close the door manually if the order to evacuate was executed in haste.

[Ssnake]

3 hours ago, Stuart Galbraith said:

I can't see where a 25 percent change in availability comes from.

...from a small sample size, of course. Once of the CR1s was one of those dog tanks that broke down all the time, and nobody knows why it's always this tank, but you also know that this tank will break down next, no matter how many repairs are committed to it. Every tanker remembers one of those, I suppose. One of those slipped into the trials - there you go.

[Stuart Galbraith]

Oh, a hangar queen. I got you.

It works the other way too of course. Bob Griffin whom used to post here, he had a Chieftain mk2, which defied all expectations and seldom if ever broke down. Which is odd, because the mk2 was the most unreliable of the lot. Deux Ex Machina I guess.

[Ssnake]

I've always associated hangar queens with airplanes - but yeah, it amounts to the same thing. And you have only a limited number of tanks in a trial, sometimes only two per vehicle type, sometimes four, but probably not more than that.

Resulting statistics (without error bars) are useful only under the assumption that all samples are of the same quality. But this just isn't the case. So, a good statistician would also calculate how much the small sample size may have skewed the results, but few army officers, even if they were once trained in stochastics, still remember the math (I certainly forgot about it after all those years - except that it needs to be done, so I guess I could read myself back into the topic if necessary). But if they don't know it and if their superiors aren't interested in those kinds of details - e.g., if a certain report is supposed to support a certain agenda - well, you end up with a report like this where not everything is very plausible.

It doesn't even have to be malfeasance, just bog standard laziness plus confirmation bias in action.

[Harkonnen]

7 hours ago, bojan said:

Why are blast doors open? Are they open by default (sounds to me like a bad idea) in case of tank not being powered?

Maybe they had no time to close after mine explosion

[GJK]

6 hours ago, Stuart Galbraith said:

Have you read of it being a major source of failure?I've personally have not.  Not tor the point where it caused a 25 percent difference in availability anyway. That's Chieftain style levels of failure.

Besides, I looked over one of these prototypes in 1994. It was built on a Challenger 1 driver training tank, even retaining the original side plates. I can't be certain they didn't replace the transmission and hydrogas suspension of course, but there was no obvious indication they changed anything but the lighting cluster. I'm dont believe they even build a driving test rig.

The TN37 gearbox in CR1 was the major source of unreliability.  CRARRV was introduced with the TN54, which was also used in CR2.  Plus I believe CR2 was built with the automotive mods which CR1 did not get untill the Gulf War.  Apparently known issues which the Army (Treasury?) were prepared to put up with until really necessary.

Best,

Greg.

[Stuart Galbraith]

9 hours ago, GJK said:

The TN37 gearbox in CR1 was the major source of unreliability.  CRARRV was introduced with the TN54, which was also used in CR2.  Plus I believe CR2 was built with the automotive mods which CR1 did not get untill the Gulf War.  Apparently known issues which the Army (Treasury?) were prepared to put up with until really necessary.

Best,

Greg.

Was it really that bad? Ive not read of any particular problems in Operation Granby. OTOH, they did pick BAOR apart for spares, so perhaps that was why. 

The only mods Im aware C1 got were,

Armoured Charge Bins.

Uparmour, which was fitted to go into Kuwait in close support role to the USMC, which never ultimately happened.

Looking at the update to the user manual, there seems to have been some changes to the fire control. Im not clear exactly what, but supposedly they did do some tweets to the fire control (CSS I think?) to make it process faster.

New filters I think, because the dust injestion was so bad. Though they found that fitting the armoured skirts did a lot to bring that down.

There was also an aircon system that looks liked they had nicked from the outside of an industrial facility, but that was trialed just in time for the war to end, so they never fitted it to any operational vehicles.

Do you know what the others were?

 

[GJK]

Evening Stuart,

You're confusing the Granby mods with the additional mods Mark 2 Challengers got to bring them up to similar protection levels as the Mark 3 (7 Brigade had to swap their Mark 2 for Mark 3 before they left Germany, but when 4 Brigade deployed later there were not enough Mark 3 left so they were equipped with Mark 2).  The main one was the armoured charge bins to replace the water jacket ones.

The automotive mods were part of the Quayside Modification Programme carried out on the vehicles when they arrived in Al Jubayl.  For Challenger, this was 14 mods, the bulk of which were improvements to the air filtration and chilling systems (according to the official review of British Army logistics in the Gulf, 'Blackadder's War', supported by the Haynes book).  I have seen an interview with the CO of 7 Armoured Workshop REME (the unit which carried out the QMP for 7 Brigade) on YouTube where he stated the deficiencies with the Challenger air filtration system were known about but were tolerated because it was only Soltau where dust was a problem (BATUS used Chieftain at this time).

The Haynes book also states that the clutch pack and steering unit of TN37 were the main sources of unreliability.  The gearbox also comes up in an interview with General Cordingley when discussing Challenger also (from his time as a staff officer working on the project to convert Shir 2 to Challenger, then as 7 Brigade commander).

Best,

Greg.

Edited March 25 by GJK