Jump to content

Ajax Issues


Dawes
 Share

Recommended Posts

On 8/2/2021 at 3:44 PM, Stuart Galbraith said:

It also would leave the door open for replacing warrior with CV90 at a later date.

images?q=tbn:ANd9GcRUcaM7p2eXlHxdJUcLooa

Link to comment
Share on other sites

  • Replies 169
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

7 hours ago, Stuart Galbraith said:

I cant remember any on British trials. I can think of a few that showed inadequate gunnery accuracy (Black Prince), inadequate crew space (Valiant), and even one too big for its own good (Tortoise). But im damned if I can think of one that didnt get the suspension right at the very least. You would probably have to go back to the 20's for that.

Not even the Covenanter...

Link to comment
Share on other sites

Good point. And for all the flaws in Chieftain, the suspension was really good for its day.

We basically we pissed away over 100 years of tracked AFV design, and outsourced it to a bunch of chebs. It's like Mercedes giving up designing cars and letting Trabant design them instead.

(Actually the Trabant design team was far sighted and invented the Hot Hatchback, but let's not complicate things)

Edited by Stuart Galbraith
Link to comment
Share on other sites

10 hours ago, Stuart Galbraith said:

You just now they are probably going to end up with BV202's with a grenade launcher. :D

A revamped Windsor Carrier at 3 million a piece 

Link to comment
Share on other sites

10 hours ago, Stuart Galbraith said:

Good point. And for all the flaws in Chieftain, the suspension was really good for its day.

We basically we pissed away over 100 years of tracked AFV design, and outsourced it to a bunch of chebs. It's like Mercedes giving up designing cars and letting Trabant design them instead.

(Actually the Trabant design team was far sighted and invented the Hot Hatchback, but let's not complicate things)

Almost anyone can make a car with real metal and tens of thousands of dollars per car.  It probably took some seriously savvy engineering to make a car out of tinfoil and cardboard that would actually run (for a given definition of run) like the Trabbi.

Link to comment
Share on other sites

36 minutes ago, R011 said:

Almost anyone can make a car with real metal and tens of thousands of dollars per car.  It probably took some seriously savvy engineering to make a car out of tinfoil and cardboard that would actually run (for a given definition of run) like the Trabbi.

You are right, im being unfair to Trabant.

Link to comment
Share on other sites

If you look at the acceleration or cross country performance, not to mention ease of repair, not to mention the Israelis used much the same suspension to traverse the very worst of terrain in their first two Merkava's, thats one we could have an robust debate about. But its the Ajax thread, and ive gone off topic talking about Trabants, I will leave it there.

Edited by Stuart Galbraith
Link to comment
Share on other sites

In terms of acceleration and cross-country performance, the Chieftain was worse than contemporaries. The Horstman suspension provided a maximum spring travel of only 241 mm. The M60A1 (312 mm) and AMX-30 (278 mm) with their torsion-bar suspensions were quite a bit better - not to the Leopard 1's torsion-bar system (with a maximum travel of 407 mm!).

You can take a look at the Dutch trials of the Chieftain vs Leopard 1, their impression of the Chieftain's off-road mobility wasn't really positive.

 

Merkava uses a different suspension with much greater travel. In technical terms that may be related to the Horstman system, but the implementation is very different. The Israeli's also weren't really happy with the performance of their initial suspension systems, making multiple changes on newer variants.

Link to comment
Share on other sites

Curious they were not happy with it, when Israel seemingly emphasised the Centurion and super Sherman on the Golan, because it was too much for torsion bars. Look for a photo of an M60 or M48 in 1973 on the Golan, you won't find one. I've looked in vain.

Read the George Forty book on Chieftan, and you will find an account by a British crew that transitioned from Centurion to Chieftain, and were well impressed at its ability over poor terrain. Probably more to do with wider tracks and the preselective gearbox, but it all helped. I'm not much impressed by the Dutch evaluation, they had made their mind up to buy leopard, they were hardly going to say anything glowing about Chieftain at that point.

And yes, it was noisy, but ive still never read anything about vibration remotely comparable to what's been written about Ajax. And it's what, 15 tons lighter?

Link to comment
Share on other sites

The Centurion's suspension had even less total travel, no wonder that the Chieftain was an improvement. The suggestion that the M50/M51 Sherman with HVSS were better suited for the Golan Heights than the M48 and M60A1 is a bit silly. American tank designers aren't stupid.

There are many more factors deciding which tank unit is deployed where in case of a war. The Golan Heights provided the IDF with favourable terrain, allowing a relatively small force to hold their position against the Syrian tank units even when using outdated/under-gunned tanks such as the AMX-13 as well as the M50 & M51 Sherman tanks.

On the West Bank and Sinai meanwhile the IDF was expecting to encounter even larger tank forces on a more open terrain, where things such as armor protection, optics and rangefinders start to matter more.

2 hours ago, Stuart Galbraith said:

I'm not much impressed by the Dutch evaluation, they had made their mind up to buy leopard, they were hardly going to say anything glowing about Chieftain at that point.

Ah, the good old "nobody gave the British tanks a chance", even though the actual data recorded during trials shows that there is a reason for that.

2 hours ago, Stuart Galbraith said:

And yes, it was noisy, but ive still never read anything about vibration remotely comparable to what's been written about Ajax. And it's what, 15 tons lighter?

The Chieftain wasn't designed to start as a 40 tonnes tank that somehow ended up a 55 tonnes tank due to last minute requirement and engineering changes. The ASCOD 2 wasn't meant to weigh 42 tonnes, it got a lot fatter during development when becoming the AJAX. 

Perception is also a lot different. The vibration behaviour of the Chieftain and Centurion at 60-70 kph (or 40 kph off-road) is not known to the average soldier, as these tanks under normal circumstances never reached such speeds.

Link to comment
Share on other sites

13 hours ago, methos said:

The Centurion's suspension had even less total travel, no wonder that the Chieftain was an improvement. The suggestion that the M50/M51 Sherman with HVSS were better suited for the Golan Heights than the M48 and M60A1 is a bit silly. American tank designers aren't stupid.

There are many more factors deciding which tank unit is deployed where in case of a war. The Golan Heights provided the IDF with favourable terrain, allowing a relatively small force to hold their position against the Syrian tank units even when using outdated/under-gunned tanks such as the AMX-13 as well as the M50 & M51 Sherman tanks.

On the West Bank and Sinai meanwhile the IDF was expecting to encounter even larger tank forces on a more open terrain, where things such as armor protection, optics and rangefinders start to matter more.

Ah, the good old "nobody gave the British tanks a chance", even though the actual data recorded during trials shows that there is a reason for that.

The Chieftain wasn't designed to start as a 40 tonnes tank that somehow ended up a 55 tonnes tank due to last minute requirement and engineering changes. The ASCOD 2 wasn't meant to weigh 42 tonnes, it got a lot fatter during development when becoming the AJAX. 

Perception is also a lot different. The vibration behaviour of the Chieftain and Centurion at 60-70 kph (or 40 kph off-road) is not known to the average soldier, as these tanks under normal circumstances never reached such speeds.

You cannot pretend the Dutch had an open mind went they trialled Chieftain because they clearly did not. They had already made their mind up to buy Leopard. Good God, you only have to look at the photo of the commander of the Dutch Armoured Forces driving Chieftain to see his mind was already made up. :D

Read other accounts written by other nations who trialled it, they all complain about the engine, but nobody, not once, complains about the suspension. And that Israel adopted pretty much the same suspension setup, should surely.tell you something. It was clearly  acceptable for the role in which it was itended.

it might be silly, but its what the IDF was clearly doing. They broke torsion bars all the time on the Golan.. Maybe they also broke Centurion suspension too, but it was one hell of a lot easier to fix if nothing else. The worse complaint ive read was the terrain bent the outer track edge making it impossible to extract track pins. So they trimmed the edge off the track every 4 or so pins to they could extract 4 track link when they had to. But of the suspension, no complaints.

What does this exactly have to do with Ajax? Well absolutely nothing, other than British AFV designers, even on a bad day, were clearly capable of designing a machine that didnt suffer from excessive vibration, and we have now outsourced to people who clearly cannot.

Im not really sure why this proved such a contentious point, but such is Tanknet I guess.

 

Edited by Stuart Galbraith
Link to comment
Share on other sites

3 hours ago, Stuart Galbraith said:

Read other accounts written by other nations who trialled it, they all complain about the engine, but nobody, not once, complains about the suspension.

All of the nations who ended up adopting the Chieftain MBT did so after not conducting comparative trials with alternatives. All of them had previously used older and worse tanks. It is no wonder that they did not complain about improvements in performance.

You however claimed that the Chieftain's suspension was "really good for its day", which is not supported by available data. If you don't want to believe in the Dutch being able to conduct an unbiased, open-minded evaluation of the Leopard 1 and Chieftain tank, I could recommend reading the German report on the evaluation of the Chieftain MBT in 1966. Germany and the UK traded tanks (the Leopard 1 MBT located at Bovington was given to the UK in exchange for a Chieftain) for trials. Both countries already had adopted their own tanks, there was no commercial interest in these tests, they were just conducted for gathering data for reference for future tank concepts/programs.

In the German report, the Chieftain's mobility (and reliability) isn't painted in a good light. There is no indication that the suspension was "really good for its day". The British report on their own trials (conducted on 10th of June 1966 at Long Valley, Aldershot) comes to another conclusion (off-road mobility comparable), but it contains a number of really odd statements such as:

  • Leopard 1 supposedly not being able to drive at full speed, because the rubber-coated road wheels would overheat (never happened in service and even the faster Leopard 2 tank has no problems with overheating road wheels)
  • Chieftain being fasted in one off-road test (main reason for this test was to see if gunner could detect targets while on the move) was explained with driver's having freedom of choice for the track path. The British driver in the Leopard 1 choose a worse track than the British driver in the Chieftain, so the British military concluded that Chieftain was at least as good as Leopard 1...
  • Speed during off-road driving was based on crews' feelings. The British crew in the Chieftain was more experienced, yet the Leopard 1 (also with British crew) was slightly faster. The explanation according to the British MoD was that the Leopard 1's crew was driving reckless and accepted a higher risk of injury. No equipment was used to measure quality of ride. All off-roads speeds (as achieved by Centurion, Chieftain and Leopard 1) were seen as unrealistically high and not common in actual service.

The Chieftain Mk 1 used in the tests was a pre-production model without full combat load, weighing two tonnes less than the series version...

 

But you probably will tell me that this is all irrelevant, that the German trials are not to be believed and that the British trials - despite their own data showing Leopard 1 performing better - are to be ignored and all issues I have with the British excuses for the Leopard 1 performing better are to be assumed 100% unreasonable and false.

3 hours ago, Stuart Galbraith said:

And that Israel adopted pretty much the same suspension setup, should surely.tell you something. It was clearly  acceptable for the role in which it was itended.

They did not. Please stop repeating this myth.

Chieftain's Horstman suspension:

kB381bG.jpegVEHkznG.png

Merkava 1's suspension:

zgvsf4j7ehc11.jpg

71.png?w=2000&h=

These suspensions are very different. The only common aspect is that both utilize springs instead of twisting metal rods (torsion bars). The Chieftain's Horstman suspension has two wheels connected to a single horizontal spring (and in case of the frontal wheel pair to a shock absorber), which massively limits its travel. That's why the Chieftain's suspension allows a maximum travel of only 241 mm.

The suspension of the Merkava 1 and 2 utilize vertical placed springs and has individual shock absorbers for each road wheel (in the areas where shock absorbers are fitted). There is no technical relation to the Centurion and Chieftain, in fact the Merkava's early suspension is design-wise more related to the Cromwell tank (but not derived from that). The vertical placement of the springs allows achieving a much greater total travel, in case of the improved suspension fielded on the Merkava 4 a total spring travel of more than 600 mm is possible.

3 hours ago, Stuart Galbraith said:

They broke torsion bars all the time on the Golan.. Maybe they also broke Centurion suspension too, but it was one hell of a lot easier to fix if nothing else.

Yes, the reason for moving towards an external spring-based suspension was the ease of repair and maintenance. Also making high quality torsion bars isn't easy (Europe and the United States benefitted from their automotive industry having already developed high quality torsion bars).

However the main reason why the Centurion was deployed in the Golan Heights was not the suspension. The steel tracks without rubber pads were better for the rocky terrain and the Magachs with their optical rangefinders were more needed elsewhere .The M48 also saw use in the Golan Heights during the Yom-Kippur War.

us-m-48-patton-magach-tank-golan-heights

3 hours ago, Stuart Galbraith said:

What does this exactly have to do with Ajax? Well absolutely nothing, other than British AFV designers, even on a bad day, were clearly capable of designing a machine that didnt suffer from excessive vibration, and we have now outsourced to people who clearly cannot.

As I said previously: the Chieftain never achieved the same speeds and hence never was subject to the same forces causing excess vibrations. The FVRDE suggested that achieving 16-20 kph across rough terrain with the Chieftain was unrealistic, risked the crew's health and meant that the crew could not perform any of its tasks due to the shaky, rough ride.

Edited by methos
Link to comment
Share on other sites

22 minutes ago, methos said:

...Also making high quality torsion bars isn't easy (Europe and the United States benefitted from their automotive industry having already developed high quality torsion bars)....

Israel was acquiring torsion bars for T-54-55 sometime between 1968 and 1971. via Yugoslavia and Romania, and later in  the late '70s via Yugoslavia. Which indicates they did not produce those. Did Israel ever make torsion bars for US made tanks or were those were also imports?

Link to comment
Share on other sites

36 minutes ago, methos said:

All of the nations who ended up adopting the Chieftain MBT did so after not conducting comparative trials with alternatives. All of them had previously used older and worse tanks. It is no wonder that they did not complain about improvements in performance.

You however claimed that the Chieftain's suspension was "really good for its day", which is not supported by available data. If you don't want to believe in the Dutch being able to conduct an unbiased, open-minded evaluation of the Leopard 1 and Chieftain tank, I could recommend reading the German report on the evaluation of the Chieftain MBT in 1966. Germany and the UK traded tanks (the Leopard 1 MBT located at Bovington was given to the UK in exchange for a Chieftain) for trials. Both countries already had adopted their own tanks, there was no commercial interest in these tests, they were just conducted for gathering data for reference for future tank concepts/programs.

In the German report, the Chieftain's mobility (and reliability) isn't painted in a good light. There is no indication that the suspension was "really good for its day". The British report on their own trials (conducted on 10th of June 1966 at Long Valley, Aldershot) comes to another conclusion (off-road mobility comparable), but it contains a number of really odd statements such as:

  • Leopard 1 supposedly not being able to drive at full speed, because the rubber-coated road wheels would overheat (never happened in service and even the faster Leopard 2 tank has no problems with overheating road wheels)
  • Chieftain being fasted in one off-road test (main reason for this test was to see if gunner could detect targets while on the move) was explained with driver's having freedom of choice for the track path. The British driver in the Leopard 1 choose a worse track than the British driver in the Chieftain, so the British military concluded that Chieftain was at least as good as Leopard 1...
  • Speed during off-road driving was based on crews' feelings. The British crew in the Chieftain was more experienced, yet the Leopard 1 (also with British crew) was slightly faster. The explanation according to the British MoD was that the Leopard 1's crew was driving reckless and accepted a higher risk of injury. No equipment was used to measure quality of ride. All off-roads speeds (as achieved by Centurion, Chieftain and Leopard 1) were seen as unrealistically high and not common in actual service.

The Chieftain Mk 1 used in the tests was a pre-production model without full combat load, weighing two tonnes less than the series version...

 

But you probably will tell me that this is all irrelevant, that the German trials are not to be believed and that the British trials - despite their own data showing Leopard 1 performing better - are to be ignored and all issues I have with the British excuses for the Leopard 1 performing better are to be assumed 100% unreasonable and false.

They did not. Please stop repeating this myth.

Chieftain's Horstman suspension:

kB381bG.jpegVEHkznG.png

Merkava 1's suspension:

zgvsf4j7ehc11.jpg

71.png?w=2000&h=

These suspensions are very different. The only common aspect is that both utilize springs instead of twisting metal rods (torsion bars). The Chieftain's Horstman suspension has two wheels connected to a single horizontal spring (and in case of the frontal wheel pair to a shock absorber), which massively limits its travel. That's why the Chieftain's suspension allows a maximum travel of only 241 mm.

The suspension of the Merkava 1 and 2 utilize vertical placed springs and has individual shock absorbers for each road wheel (in the areas where shock absorbers are fitted). There is no technical relation to the Centurion and Chieftain, in fact the Merkava's early suspension is design-wise more related to the Cromwell tank (but not derived from that). The vertical placement of the springs allows achieving a much greater total travel, in case of the improved suspension fielded on the Merkava 4 a total spring travel of more than 600 mm is possible.

Yes, the reason for moving towards an external spring-based suspension was the ease of repair and maintenance. Also making high quality torsion bars isn't easy (Europe and the United States benefitted from their automotive industry having already developed high quality torsion bars).

However the main reason why the Centurion was deployed in the Golan Heights was not the suspension. The steel tracks without rubber pads were better for the rocky terrain and the Magachs with their optical rangefinders were more needed elsewhere .The M48 also saw use in the Golan Heights during the Yom-Kippur War.

us-m-48-patton-magach-tank-golan-heights

As I said previously: the Chieftain never achieved the same speeds and hence never was subject to the same forces causing excess vibrations. The FVRDE suggested that achieving 16-20 kph across rough terrain with the Chieftain was unrealistic, risked the crew's health and meant that the crew could not perform any of its tasks due to the shaky, rough ride.

Chieftain Mk1, which had a  585bhp engine, which the Army saw made it only suitable for training, and the first production tanks which had a 650bhp engine, culminating with a 750bhp in the fairly definative Chieftain Mk5. You see the problem? You are citing the very earliest models of Chieftain against Leopard 1, and are ignoring the fairly considerable strides that occurred in uprating the engines power before any vehicles were delivered to any foreign customers.  It was never a good engine, but you are presenting it as if the story never moved on from Mk1, when it very clearly did. The mk13 was actually fairly good, for an L60 anyway.

Ok, so the arrangement of the springs is different, but its still an externally mounted coil spring suspension. More to the point, the Israelis examined Chieftain, which had pretty much the same suspension as Centurion, and were reportedly happy with it. Yes, admittedly the Iranians wanted uprated suspension with more travel, but they didnt find i so much of a problem they decided to go back and retrofit all previous version they built. Even Shir 1 had coil springs, not hydrogas. The Dutch actually experimented with fitting hydrogas to Centurion, and didnt find enough of an improvement to do a fleet wide replacement.

Yes, I know it didnt go so fast as Ajax, but as the Ajax seems to suffer from vibration even at fairly low speeds as best I can tell, with the utmost of respect its kind of missing the point.

 

Link to comment
Share on other sites

2 hours ago, methos said:

The only common aspect is that both utilize springs instead of twisting metal rods (torsion bars)

Needless to say, springs are torsion bars too, just ... curly.

Link to comment
Share on other sites

Conqueror was good, for what was a very niche role. Challenger 1 was good, for an interim tank excessively rushed into service in what was essentially institutional  panic. Chieftain was good, for all its flaws and treasury limitations. The Saladin family were capable and highly useful vehicles. I think CVRT, for its era was actually pretty groundbreaking.

We were among the first of the NATO nations to introduce Thermal sights. We developed Chobham, still the cornerstone of NATO tank protection. And lastly we developed the 105mm that was a mainstay of most Western MBTs till the end of the Cold war.

I think we more right than we got wrong. Rather like English football, it's too easy to fall into the trap of slagging it off without looking at the subject objectively. It's too easy to take cheap shots.

 

Link to comment
Share on other sites

7 hours ago, bojan said:

Did Israel ever make torsion bars for US made tanks or were those were also imports?

I believe they were imported, but @Mighty_Zuk might know more on the matter.

6 hours ago, Stuart Galbraith said:

Chieftain Mk1, which had a  585bhp engine, which the Army saw made it only suitable for training, and the first production tanks which had a 650bhp engine, culminating with a 750bhp in the fairly definative Chieftain Mk5.

The tank in question had a 650 bhp engine. Note that the weights are listed in long (imperial) tons, resulting in the Leopard 1 being 39.75 long tons = 40.4 metric tons heavy. The Chieftain weighs 50.2 long tons, which is equal to 51 metric tons. 1133916952_ChieftainWeight.thumb.PNG.9d428ddb221c1e6ac7b91e5d8ee98211.PNG

According to the Chieftain's user manual (that IIRC you shared on Tank Net), the Chieftain Mk 1 tank is supposed to weigh 52.94 metric tons, the Mk 2 model is 508 kg lighter due to its refined/reduced turret armour. The weight discrepancy is not explained in the text. It is specifically stated that the Centurion was running unladen and hence lighter, but that's it. It is also noted that the British bhp figures are "catalogue" figures not including power absorbed by the cooling fans and transmission. The German figure for the Leopard 1 (830 PS aka 818 bhp) is measured according to the DIN 70020 standard and already includes the power loss from cooling fans and transmission.

 

I don't see how the late Chieftain Marks featuring an uprated engine is relevant for the discussion whether the Chieftain had a very good suspension for its time. The Chieftain Mk 5 entered production in 1975, it is hardly relevant for this discussion as it would need to be compared to contemporary tanks then (and also had the same suspension as earlier marks). You argued that the British engineers made a very good suspension for the Chieftain and implied that the Ajax wouldn't have issues, if it had been designed by British engineers instead. I cannot agree with your statement about Chieftain having a good suspension for its time - it was average at best.

I cannot agree with your logic regarding Ajax, specifically given that (late) changes in the British requirements have caused most of the Ajax issues. Pizarro and Ulan have no issues with vibrations, no issues with the ammunition feed system of the main gun, no issues with noise generation and are also not heavier than originally specified. Even the current ASCOD 42 does not share the Ajax's problems based on reports on the currently on-going Czech trials.

Obviously defending General Dynamics European Land Systems (and Lockheed-Martin as turret subcontractor) against all criticism isn't reasonable. GDELS also made a lot of errors, but I believe that many key flaws in the program were introduced by the British MoD not specifying certain requirements and changing others during development.

One nice example is the CTAS gun: the UK MoD failed to specify that the Ammunition Handling System (AHS) developed by CTA International had to be utilized. That's a failure of the UK MoD. Hence greedy Lockheed-Martin decided to design its own AHS, which caused issues as the design of the CTAS gun had not been frozen by the UK MoD (another failure!), resulting in CTA International making changes to the gun's dimension and interfaces, which rendered LM's originally AHS unreliable and faulty. That has been confirmed by Lockheed-Martin and General Dynamics UK as a primary source in the turret's initial reliability issues.

Moving the final assembly to England (creating a handful of jobs at the expense of increasing the program's cost and introducing a long delay into the program), changing armour supplier and components specs (with Ajax gaining 2-3 tonnes over the initial design goal) are other examples of the UK MoD's failures. The poor build quality is a major failure of GDELS, though it arguably would have been less of an issue if final assembly took place in Spain (where the issue would have been discovered earlier and the responsible factors could have been identified and eliminated).

6 hours ago, Stuart Galbraith said:

Ok, so the arrangement of the springs is different, but its still an externally mounted coil spring suspension.

It is a different type of suspension. Arguing that the Chieftain's suspension was good because the Israeli's would have copied it, is not valid.

6 hours ago, Stuart Galbraith said:

More to the point, the Israelis examined Chieftain, which had pretty much the same suspension as Centurion, and were reportedly happy with it.

It was an improvement over Centurion and M48 (not to mention Sherman), obviously they were happy with improved performance - but when they designed their own tanks or converted others, they choose a solution much better suited for their needs.

6 hours ago, Stuart Galbraith said:

Yes, I know it didnt go so fast as Ajax, but as the Ajax seems to suffer from vibration even at fairly low speeds as best I can tell, with the utmost of respect its kind of missing the point.

This issue is the result of British-demanded modifications to the design, not an inherent "feature" of the ASCOD. There have been no issues with the Ulan and nowadays three generation of Pizarro vehicles.

The British MoD simply doesn't know how to run procurement and development programs on its own, after having relied for decades on in-house designs (before giving up this capacity in the 1980s). Ajax's weight grew following the demanded design changes, but no order (and no money) was given for altering the existing drivetrain components. The contractor saw no reason to invest time and personnel on its own and focused its capacities on dealing with the rest of the Army's (at times growing) wishlist for Ajax changes.

As for "fairly low speeds", the British Army reportedly limited speed during several trials to 20 mph to prevent soldiers from experience the excessive vibrations and noise. That's still faster than the Chieftain was considered save to ride in heavy terrain (by the UK MoD). Citing Chieftain as reference for a supposedly good design isn't working here.

2 hours ago, Stuart Galbraith said:

We were among the first of the NATO nations to introduce Thermal sights.

After the Americans, the Germans and the Dutch.

2 hours ago, Stuart Galbraith said:

I think we more right than we got wrong. Rather like English football, it's too easy to fall into the trap of slagging it off without looking at the subject objectively.

I think the English football is a good analogy for the British tank designs of the Cold War, but probably in a very different way than you 😁

Edited by methos
Link to comment
Share on other sites

11 hours ago, methos said:

I believe they were imported, but @Mighty_Zuk might know more on the matter.

The tank in question had a 650 bhp engine. Note that the weights are listed in long (imperial) tons, resulting in the Leopard 1 being 39.75 long tons = 40.4 metric tons heavy. The Chieftain weighs 50.2 long tons, which is equal to 51 metric tons. 1133916952_ChieftainWeight.thumb.PNG.9d428ddb221c1e6ac7b91e5d8ee98211.PNG

According to the Chieftain's user manual (that IIRC you shared on Tank Net), the Chieftain Mk 1 tank is supposed to weigh 52.94 metric tons, the Mk 2 model is 508 kg lighter due to its refined/reduced turret armour. The weight discrepancy is not explained in the text. It is specifically stated that the Centurion was running unladen and hence lighter, but that's it. It is also noted that the British bhp figures are "catalogue" figures not including power absorbed by the cooling fans and transmission. The German figure for the Leopard 1 (830 PS aka 818 bhp) is measured according to the DIN 70020 standard and already includes the power loss from cooling fans and transmission.

 

I don't see how the late Chieftain Marks featuring an uprated engine is relevant for the discussion whether the Chieftain had a very good suspension for its time. The Chieftain Mk 5 entered production in 1975, it is hardly relevant for this discussion as it would need to be compared to contemporary tanks then (and also had the same suspension as earlier marks). You argued that the British engineers made a very good suspension for the Chieftain and implied that the Ajax wouldn't have issues, if it had been designed by British engineers instead. I cannot agree with your statement about Chieftain having a good suspension for its time - it was average at best.

I cannot agree with your logic regarding Ajax, specifically given that (late) changes in the British requirements have caused most of the Ajax issues. Pizarro and Ulan have no issues with vibrations, no issues with the ammunition feed system of the main gun, no issues with noise generation and are also not heavier than originally specified. Even the current ASCOD 42 does not share the Ajax's problems based on reports on the currently on-going Czech trials.

Obviously defending General Dynamics European Land Systems (and Lockheed-Martin as turret subcontractor) against all criticism isn't reasonable. GDELS also made a lot of errors, but I believe that many key flaws in the program were introduced by the British MoD not specifying certain requirements and changing others during development.

One nice example is the CTAS gun: the UK MoD failed to specify that the Ammunition Handling System (AHS) developed by CTA International had to be utilized. That's a failure of the UK MoD. Hence greedy Lockheed-Martin decided to design its own AHS, which caused issues as the design of the CTAS gun had not been frozen by the UK MoD (another failure!), resulting in CTA International making changes to the gun's dimension and interfaces, which rendered LM's originally AHS unreliable and faulty. That has been confirmed by Lockheed-Martin and General Dynamics UK as a primary source in the turret's initial reliability issues.

Moving the final assembly to England (creating a handful of jobs at the expense of increasing the program's cost and introducing a long delay into the program), changing armour supplier and components specs (with Ajax gaining 2-3 tonnes over the initial design goal) are other examples of the UK MoD's failures. The poor build quality is a major failure of GDELS, though it arguably would have been less of an issue if final assembly took place in Spain (where the issue would have been discovered earlier and the responsible factors could have been identified and eliminated).

It is a different type of suspension. Arguing that the Chieftain's suspension was good because the Israeli's would have copied it, is not valid.

It was an improvement over Centurion and M48 (not to mention Sherman), obviously they were happy with improved performance - but when they designed their own tanks or converted others, they choose a solution much better suited for their needs.

This issue is the result of British-demanded modifications to the design, not an inherent "feature" of the ASCOD. There have been no issues with the Ulan and nowadays three generation of Pizarro vehicles.

The British MoD simply doesn't know how to run procurement and development programs on its own, after having relied for decades on in-house designs (before giving up this capacity in the 1980s). Ajax's weight grew following the demanded design changes, but no order (and no money) was given for altering the existing drivetrain components. The contractor saw no reason to invest time and personnel on its own and focused its capacities on dealing with the rest of the Army's (at times growing) wishlist for Ajax changes.

As for "fairly low speeds", the British Army reportedly limited speed during several trials to 20 mph to prevent soldiers from experience the excessive vibrations and noise. That's still faster than the Chieftain was considered save to ride in heavy terrain (by the UK MoD). Citing Chieftain as reference for a supposedly good design isn't working here.

After the Americans, the Germans and the Dutch.

I think the English football is a good analogy for the British tank designs of the Cold War, but probably in a very different way than you 😁

Im not sure its the turret armour. I do recall that between the Mk1 and the Mk2 the armour on the hull glacis was simplified and lightened. They also saved a lot of weight on the searchlight housing which was armoured in the Mk1 and not in the Mk2.

Read what I said again, I said even the Chieftain, which had its fair share of problems, never had any complaints about the suspension.

It didnt. Im not realy sure why there was the need for the chapter and verse on why you hate Chieftain, but again you miss my initial point. We could design AFV's that had no problems with suspension, and now we cant, because we prefer to outsource. You have not addressed that point. Or maybe you did, you wrote so much its hard to keep track. :)

And yes, you are welcome for the manual. I keep meaning to get around to doing the Mk11-Mk12.

 

 

Edited by Stuart Galbraith
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share


×
×
  • Create New...