Comets In Europe

[ajmac]

You see much written about the Pershing at the end of The Second World War but the Comet seems to get a rough deal.... considering how good it was:-\

 

Does anyone have details concernong the deployment of the first Comets in December 1944 in NW Europe? I've seen the odd photo but never read any combat reports or seen any data concerning the overall performance of the vehicle, it seems to have been somewhat over shadowed by the Centurion.

I appreciate that there will not be many Tank vs Tank accounts as the Germans didn't have many left by that time!

 

PS. Did any of the Finnish Comets come to the UK for restoration following the auction a couple of years ago?

[antarmike]

How good was it, I thought the only good british tank to came out of WW2 was Centurion (A41), and that never saw wartime combat...

(puts on steel helmet and retires immediately)

[ajmac]

Considering all the rubbish we manufactured during the war.... Comet was rather good :-)

 

Better Offroad than Sherman/Cromwell/Churchill

Faster than Sherman/Churchill

More powerful AP round than Sherman/Cromwell/Churchill

Thicker armour than Sherman/Cromwell

 

Both Centurion and Comet shared many design features.

Edited February 24, 2009 by ajmac

[antarmike]

Is the picture I posted in the Explorer gallery of a tank pushing over an Explorer, a Comet? I don't know a lot about Armour, I only get enthused about things I can see myself ending up owning?

Edited February 24, 2009 by antarmike

[Adrian Barrell]

Considering all the rubbish we manufactured during the war.... Comet was rather good :-)

 

Better Offroad than Sherman/Cromwell/Churchill

Faster than Sherman/Churchill

More powerful AP round than Sherman/Cromwell/Churchill

Thicker armour than Sherman/Cromwell

 

Both Centurion and Comet shared many design features.

 

Hmm,

 

Churchill could go places you wouldn't get a Comet and Cromwell was as good off road as Comet.

 

Anything was faster than Churchill.....

 

Worse HE than any of those and as 70% of tank ammo usage was HE it's not a small consideration.

 

Bigger and heavier tank.

 

Comet was essentially a heavy Cromwell and so was closer related than Centurion.

Despite what I've written, I actually like Comet! I've had quite a bit to do with various examples over the years.

 

My point are just to show you cannot compare different vehicles too closely as most types come out better than others in one respect or another.

 

Mike, yes that's a Comet. It probably got fed up of going so slowly.......

[REME 245]

Obviously a reliable tank because it was based on proven components but really a year late and already inferior to a lot of German Tanks.

 

The stepped front armour did not give as good as protection as sloped armour and the gun was not as powerful as the 17 Pounder.

[Adrian Barrell]

Mostly true and all addressed by Centurion which entered service soon after.

 

Given that Cromwells battle debut was June 44, Comets early 45 and Centurion trials in May 45, that's a lot of improvement in a short space of time.

 

I wouldn't say it was inferior to a lot of German tanks as only Panther and Tigers 1 and 2 were on a par or 'better'. Mind you, those tanks were between 2 and 3 years old by wars end....

[ajmac]

Too true Adrian.... as normal.

I know I was being rather simplistic, but just wanted to show that it wasn't a waste of production capacity :-)

Although, I was under the impression that the 77mm HE round was considerably better than the 17 Pdr HE round and that overall the 77mm was a more acturate gun than the 17 Pdr. Having said that it didn't have the armour penetration of the original 17 Pdr.

 

If you consider the Comet as a replacement for the existing British armour then it ticked all the boxes. Yes the Centurion was an all round better vehicle but it was in the next size bracket up!

 

Strangly in reality when you think about the German armour threat the British needed the Comet and Centurion in June 44 tailing off to a Sherman / Cromwell force in 1945:-D

[Adrian Barrell]

It's OK Alastair, we seem to agree on most things, sometimes it's fun putting forward a different view! :-D

 

77mm used 17 pr projectiles married to the old 3" 20 cwt AA gun case so performance was less than the 17 pr in AP but HE was no worse as 17 pr used a reduced charge for that.

 

The 17 pr/ 77mm HE round was reportedly not as good as the 75mm, it was certainly not as accurate but I don't know what the charge weights were for each and whether it was accuracy or explosive power that was being commented on. ISTR the 17pr shell used a thicker wall to allow for the greater power and so had a smaller charge.

 

Perhaps later 77mm HE used a dedicated projectile giving a better perfomance but as it was more or less the same calibre as the 75mm, it's hard to see how it could be much better without an improvement in explosive filling.

 

Early 17 pr APDS was, I understand, fairly innacurate somewhat negating it's range advantage.

[mcspool]

I wouldn't say it was inferior to a lot of German tanks as only Panther and Tigers 1 and 2 were on a par or 'better'.

 

Let´s have a look at the three aspects of tank quality:

 

1) Firepower: Tigers first, Panther second, Comet comes close to Panther AFAIK.

 

2) Protection: Tigers come first, Panther and Comet might actually be on par overall as the Panther´s side armour was quite thin.

 

3) Mobility: Comet runs circles around the Panther and Tigers.

 

Forget about the other German tanks, let alone all the AFVs cobbled up on French chassis etc.

 

- Hanno

[Bystander]

My late father who served as a radio operator to brigade HQ in the RTR (11th Armoured Div?) on national service in Germany 1950-2 always thought very highly of Comets (although I think that the only tank that he only ever travelled was the Brigadiers’ Centurion). He always scoffed at the stated maximum speed of 29 mph in books – he said that he regularly saw 45-50 mph on the speedo of following lorries on manoeuvres, and occasionally up to 55 mph – apparently it was normal practice to tie up the governor. Manoeuvres invariably consisted of practicing an orderly retreat in the face of a massive Russian attack and although the convoy speed was quite sedate, in theory, in practice once one was a few miles back in the queue one was either stationary or “driving hell for leather”.

 

If there is any interest I will post up some of his photos, together with his acerbic comments in the coming weeks. Unfortunately only one of his photos features tanks (mostly they are of various radio trucks and army life) and this is hardly one of his best. It is attached herewith. The caption on the back reads: “I took this from the turret of the Brig’s tank after the parade for Churchill. The tanks here are forming up after having just come off the parade. A Cromwell tank nearest the camera, and a Comet to the right. You can just see the flags on the tanks’ aerials. Note the exhaust gas in the trees”.

[Adrian Barrell]

With the greatest respect to your father, I have often been told of the governer being disabled and getting 55 mph out of Cromwell but the facts don't add up.

 

The governer in a Meteor is a sprung plunger in the magneto rotors and short of modifying a rotor and swapping it over, there is no way to ''tie up a governer''. Crews would not have been fiddling with mags so unless there was some sort of 'official' understanding in the unit to modify the tanks, it seems unlikely.

 

For a Comet to do 55 mph, the engine would have to run at 4400 rpm, Meteor will throw it's rods long before then and I doubt the tracks would take it either.

 

Nice picture but they are all Comets.

Edited February 26, 2009 by Adrian Barrell

[ajmac]

I was reading details of a wartime report by Rolls who were comparing the 'spec' for the Meteor with the available Tank engines from the USA, the Rolls Engineers didn't think much of what was available, stating that they couldn't get the Ford GAA to produce the quoted power output on the dyno whatever they did :-) There were even hints that they thought Ford had taken liberties with the Merlin design drawings which they had received while the British mission was looking for a company to manufacture the Merlin.

For those that don't know the V8 GAA was based on a V12 aero engine that AFAIK never went into production.

Edited February 26, 2009 by ajmac

[Maurice]

Even if it would go 50 MPH, the thing would be impossible to control , if you go in an achilles or sort at its max speed (30mph with GM`s ) you have already enough to do to keep it on the road , with the slightest corner you can loose it out of control if you are not experienced enough.

[Adrian Barrell]

I'm sure they thought the multibank was a marvel of modern engineering and were very envious!:-D

 

I understand Ford (GB) redrew the Merlin for their style of production but otherwise built it as designed.

 

Packard in the US did much the same though they still used British threads IIRC.

[ajmac]

According to the book, detailed drawings were sent to numerous manufactiring concerns in the US to enable them to decide if the Merlin was within there existing manufacturing capabilities. When Fords own design of V12 aero was shown sometime later the Rolls guys were suspicious that the Merlin drawings issue in 1940 had found their way to Fords aero design dept...

..talking of engines at B'ham Uni in the oversized books section was a copy of the Army report produced following the capture of the Tiger in North Africa (now at Bovington), it was a delight to read if only for the technical info, the period language was an added bonus - reports aren't what they were! Anyway, the engine section was tremendous all the running tests and then disassembly of the Maybach with opinions on each and every part along with notes on how it was probably manufactured and if it was a useful design feature to use in British engines.

Edited February 26, 2009 by ajmac

[antarmike]

 

The write up on the Comet I have just read says "it had a sporting chance of Killing a Panther", and that "No Comet crew would have thought for a minute of changeing it for anything else", So I reckon in hindsight it must have been pretty good.

 

How did they fare in Korea?

Edited February 26, 2009 by antarmike

[Bystander]

With the greatest respect to your father, I have often been told of the governer being disabled and getting 55 mph out of Cromwell but the facts don't add up.

 

The governer in a Meteor is a sprung plunger in the magneto rotors and short of modifying a rotor and swapping it over, there is no way to ''tie up a governer''. Crews would not have been fiddling with mags so unless there was some sort of 'official' understanding in the unit to modify the tanks, it seems unlikely.

 

For a Comet to do 55 mph, the engine would have to run at 4400 rpm, Meteor will throw it's rods long before then and I doubt the tracks would take it either.

 

Nice picture but they are all Comets.

 

My father would get very aerated whenever I placed a reference book quoting a maximum Comet speed of 29mph in front of him, emphatically stating that he had seen the speeds in question on the speedo of lorries driving immediately behind Comets. While I greatly respect your knowledge of the subject, as you quite correctly point out, there appears to be quite a volume of testimony that these speeds were seen. It is always difficult for an expert, however eminent, to argue that something is impossible, when there appears to be considerable eyewitness testimony from a variety of independent sources to the contrary.

 

As these stories seem to be widespread it would indeed appear that the doctoring/disabling or whatever of governors was indeed carried out in an organised manner within fiefdoms in the field. As the idea appears to have been to have to increase convoy speeds it would only be effective if all tanks in a column were doctored, as a tank column can only move at the speed of the slowest tank. This needs to be seen in the context of the atmosphere of the early Cold War.

 

On the question of engine revs the Meteor was of course closely related to the Merlin which was I believe rated to develop its max power at 3000 rpm in all marks, given that over-revving engines in fighter aircraft was not uncommon the engine must have been designed to survive a degree of over-revving without going bang and then of course there are the safety factors in design and construction (there are plenty of stories of Spits being dived to near-supersonic speeds). So that 4400 rpm looks credible for the average engine, even though we are more than doubling some of the key component stresses. With the greatest of respect to the wonderful work being done by restorers the engines were probably in better condition when they were new than now (certainly conrods would have been lower down their fatigue life curves). Armies are not exactly known for their parsimony so I am sure that if the odd engine failed to stand the treatment meted out no one lost any sleep over dropping a new one in.

 

Finally, yes I agree that all of the tanks in the photo look like Comets to me as well.

Edited February 27, 2009 by Bystander

[Maurice]

It is not the conrods or so failing , but your bearings will melt at these revs , and then a con rod or another part gets play , and will exit the engine . I know several guys over here in Holland involved with tractor pulling using Merlins and Meteors in their machines , and they all have bearing problems if they over rev the enginnes , actually they explode now and then into bits . There are several shots on U tube were you even can see it happening .

so if a Commet would be driving for a longer period of time over it revs , then engine life is very short.

But these speeds are not even possible with modern Leopards with 1500BHP in them .

[Mark]

Would the speedos in those days been as reliable as today's ones. most of the old ones that I have seen tend to "waver" a bit. :idea:

[Adrian Barrell]

I don't doubt the origin of the stories, just the facts. The chap who told me on several occasions, quoted me a higher speed everytime and that was only over five years of telling me....

 

The fact is the Meteor was not built to anything like the quality of the Merlin, in fact the first engines were built from reject Merlin parts and they just will not run at those speeds. If an entire unit had modified their governers to run that fast, the failure rate would have been so high, heads would have rolled.

 

I'm not saying it didn't happen, I wasn't there! I am just scepticle of the speeds quoted.

 

As an example of an old soldiers memory, I know a chap who was in Shermans throughout MW Europe whose memory is fantastic, he has written some notes on his service that make great reading but he keeps complaining my Shermans gun is mounted on it's side.... He will not have it any other way! He insisits they had a vertical sliding breech and no amount of photographic proof will convince him otherwise.

[ajmac]

Possibly the 'story' started from this event:

Early Meteor trials: 15/8/41 - 28/8/41

 

The document states:

'A speed trial on the road was carried out while we were at Farnborough. The tank covered the 'flying quarter' at about 53mph. The vehicle weighs 18.5 tones, so the performance was somewhat impressive, particularly since, at the conclusion of the test, the tank removed a telegraph pole.'

The tank in question was infact a Crusader with the Meteor installed in place of the Liberty V12.

 

Data from another source concerning the same trials:

On the day in question, Robotham saw the course for the first time and anticipated that, with his ungoverned engine of nearly twice the Liberty power, the tank might well exceed 50 mph. He pointed out to the Captain in charge of operations that trouble was likely to occur unless the course was altered....the trial proceeded anyway.

'The Rolls-Royce engined Crusder's appearance at maximum speed was spectacular. A plume of fine oil spray was ejected from the breather of the self-change gearbox (which had never been run so fast before) as the tank thundered down the road. The tank completely failed to round the corner at the end of the track plunging into the wood, decapitating a telegraph pole in the process, and distributing coils of wire in all directions. There was no official speed recorded as the crash meant the stopwatch men forgot to stop the watches. However Clan Foundry had fitted a maximum revolution recorder as a precaution which registered something in excess of 50 mph. Robotham reported: 'It is quite evident, however that the power we now provided has introduced a number of interesting problems which will require solution.'

 

Apparently the Meteor really abused the Crusaders running gear :-) the tracks were lasting an average of 50 miles before they broke!

 

More impressive than the top speed was the fact that a Cromwell could do ~25mph cross country!

Edited February 27, 2009 by ajmac

[AlienFTM]

Let´s have a look at the three aspects of tank quality:

 

1) Firepower: Tigers first, Panther second, Comet comes close to Panther AFAIK.

 

 

 

I have some documents hidden away somewhere including ballistics tables. I remember I was surprised when I first read them some 35 years ago that above about 1500m IIRC, the 75mm L70 KwK on the Panther started to outperform the 88mm L56 KwK on the Tiger 1, because the smaller calibre meant less air resistance and the longer relative barrel length (70* calibres on the Panther, 56*calibres on the Tiger) meant more kinetic energy in the round in the air.

 

I cannot remember seeing similar tables for the Tiger 2 but I believe it was an L71 (71* calibre), so I'd guess it was probably better than Panther at all ranges.

[AlienFTM]

With the greatest respect to your father, I have often been told of the governer being disabled and getting 55 mph out of Cromwell but the facts don't add up.

 

The governer in a Meteor is a sprung plunger in the magneto rotors and short of modifying a rotor and swapping it over, there is no way to ''tie up a governer''. Crews would not have been fiddling with mags so unless there was some sort of 'official' understanding in the unit to modify the tanks, it seems unlikely.

 

For a Comet to do 55 mph, the engine would have to run at 4400 rpm, Meteor will throw it's rods long before then and I doubt the tracks would take it either.

 

Nice picture but they are all Comets.

 

I cannot argue with first-person observations in the field.

 

I do remember hearing a couple of years ago (it was by the commentator at TankFest at Bovvy) that the Christie suspension had a theoretical top speed of 30mph regardless of the tank's weight, BHP or anything else (I don't remember him explaining to non-techies why this should be). I also cannot remember whether or not Comet had a Christie suspension.

 

If crews got nearly double that speed from their vehicles, good luck to them, but I think if my understanding is correct, they were asking for trouble. That said, in a "break contact" situation (did you see how I avoided using the R word?), anything, that achieves the objective is a valid course of action.

[Adrian Barrell]

Crusader did 27 mph at 1500 rpm, it's Liberty engine being governed to 1650 giving a top speed of just under 30 mph. Just by changing the engine to a Meteor gives a top speed of 46mph so to achieve 50, the Meteor must have been running at 2700+. No problem I would imagine especially as this was a specially built engine using Merlin internals.

 

Of course Crusader only weighed 18 tons, Comet being nearly twice the weight.