Thursday, August 03, 2006

Totalize - Normandy.

Have just finished reading an account and analysis of the “Totalize Battle” In Normandy by Ken Tout who has written a few books from his experience as a tank crew member of the Northampton Yeomanry which was in 33rd Armoured Brigade along with 144th and 148th R.A.C.

It is a fair account although somewhat repetitious, of the combined Tank assault by British – Canadian and Polish Armoured brigades to close the Falaise gap, and is an excellent account of some of the innovations made – again without too much rehearsal of the changes to established Tank warfare.

He makes the point – already well known – but ignored seemingly, from battles in Africa regarding the superiority of the Panzers to our Tanks – also the constant production of Shermans by the all powerful American production lines, knowing that they were inferior, whereas the British did produce the Churchill – Cromwell and finally Comet with a reasonable gun in the 17 pounder and finally for the Artillery – the late 3.7 anti tank gun.

He also quotes an old desert hand – “I have little patience with any who compares our Tank Crews unfavourably with the Panzer crews who always had the 88 on wheels to make a screen behind which they could withdraw…..Just look at the Valentines retrieved Kasserine against Mark 1V’s and Tigers by shher good training and guts and with the help of our 25 pounders in the front line firing over open sights…….. and don’t tell me our air arm compensated for ground weaponry. In Tunisia until the final six weeks – air supremacy belonged to the ME and Stuka

Which is a fair bellyache as it was the Valentine with their two pounders of the 6th Armoured Div and the mix of two and six pounders of the 21st and 25th tank bdes which turned the tide along with the heroics of the 25 pounder gunners.
It was just before the final battle from Medjez that all British Tanks were issued with the 6 pounder. The American Sherman maintained their 75mm gun throughout and it was not until the British 17 pounder became more numerous that they were fitted as “Fireflys”.

The British Tank crew losses in the Totalize battle was in the region of 5.4% as opposed to the walking Infantry of 9.85% and the Carried on Ron’s Kangeroos of 7.4%…. I sometimes wonder why we managed to survive against even one they had so many of them !…
The "air supremacy of the Daf was only after boith Tedder and Coningham went ove to Algiers and Monty was able to get Broadhurst to institute the "Cab Rank" for th El Hamma battle.


Blogger Peter G said...

There is no doubt in my mind that German tanks were superior to both British and American tanks. A number of factors contributed to this, and not, as many assume, innovative and advanced German design.

Ironically the ban on Germany having any armoured troops, under the provisions of the Versailles Treaty was a major contributing factor. Unwittingly this was to advance German tank design for as Christopher Chant (the tank historian) says "their lack of armour in this period [1919-1933] left them without the entrenched thinking and existing hardware that inevitably accompanies the existing hardware of the in-service weapons".

A second factor was handing over Czechoslovakia on a plate to Hitler by Britain and France. It is not generally remembered now, but in 1938 Czechoslovakia had some of the most advanced tank designs in the world. For example, the highly successful Czech LT-38 light tank was simply re-badged by the Germans as the PzKpfw 38(t). It was decisive in the Battle of France in 1940 in the 7th Panzer Division commanded by Rommel. Another highly successful 'German' Panzer was the Pz 39 which saw service on all fronts. German? It was, in fact, the Czech CKD/Praga LTH.

The third factor was an ability to learn quickly. Contrary to this, America seems to have believed that nothing could beat American know-how. They totally ignored the many lessons which could and should have been learnt from the Russian T-34, fitted with a high-velocity 76.2mm gun, an innovation for a medium tank. Not so the Germans. In 1941 none of the German Panzers could face or outgun the highly manoeuvrable T-34. Their reaction to meeting this formidable weapon was to take several apart and carefully study them. The result was the speedy production of two prototypes, one by Porsche and one by Henschel. The Henschel design was accepted because it was simpler. The result was the Tiger Panzer, armed with the powerful 88-mm gun Tom refers to.

British tank design was good. For example, one of the best cruiser tanks was the A27M Cromwell, but when it was introduced it was fitted with a (relatively) feeble 6-lber gun. The 75mm gun, with a muzzle velocity of 2030ft/sec (at last comparable with the T-34's), wasn't fitted to it until October 1943, and some of the earlier models were dangerously riveted together, although later variants had all-welded hulls.

Thursday, 03 August, 2006  
Blogger Tomcann said...

There is no question that many of the innovations by the Germans and their speed of introduction, left us standing particularly the Americans who seemed to be stuck with the Sherman of very litle modification. The British were well advanced in Tank design but as always - lacked the gun which was late in showing up as the 17 pdr.
Also the tactics employed by the British were often lacking in imagination - as was demonstrted in the desert by Lumsdem,Gatehouse et al as being throwbacks to the cavalry charges of WW1 - it was not until Monty got rid of most Armoured leaders that Tank tactics improved at El Hamma with the addition of the Broadhurst "Cab Rank".
One of the better leaders was "Pip" Roberts who finally took over the 11th Armoured Div in Normandy which was very successful.

Another was the Polish General who used two armoured brigades in a mass attack near Ancona which shook Kesselring.

The mass tank attack of "Goodwood " with three Armoured Divisions waa a classic disaster, whereas the initial unheard of night mass attack at Totalize was a success - dreamed up by the Canadian Symonds - was spoilied by the second wave awaiting the arrival of the US Air Force with it's penchant for "Friendly Fire"

We learned a great deal about the massed 88mm's in those battles.

Thursday, 03 August, 2006  
Blogger Peter G said...

Up to a point, Frank. 'Cromwell' was simply a designation given to the Cruiser Tank Mk VIII (Cruiser Mk I dated back to the 1920s). It was in fact an A27M, the A27L being the Cruiser Mk VII 'Centaur'. Then we have the Centaur Mk VIII A27L, from which derived the Cromwell. It was in fact the Meteor version of the A27L (L: Liberty V12 359Hp), the M stood for Meteor, the Rolls Royce Meteor V12 600 HP.

Rolls Royce converted a batch of Merlins for use in tanks and during 1941 two Crusader tanks had Meteor engines installed in place of Liberty engines for exhaustive testing, while design work proceeded on the A27 upgrade.

The Merlin was a powerful engine and ample power was available for future development. In its final guise, the Cromwell was the main equipment of British armoured divisions from 1944 to 1945.

However, even with the 75mm gun it was still inferior, by 1944 standards, to German tanks like the Panther and the PzKw IVs.

The engine was both fast and powerful, but the hull was narrow and unsuitable for a more powerful gun, the very efficient 17 pdr.

Post war, all Cromwells were modified and given a new gun turret, becoming the Charioteer. You undoubtedly met with these Frank, fitted with a 20pdr gun.

Interestingly the Cromwell III was a Centaur I re-engined with the Meteor, and the Cromwell IV was a Centaur III similarly re-engined.

No Cromwells ever had the Liberty 359 Hp engine, as I said above, that was the power plant of the Centaur.

The Cromwell variants are as follows:

Cromwell Mk I: Original model fitted with 6pdr gun, similar in appearance to Centaur I

Cromwell Mk II: Fitted with wider tracks, 15½ in instead of 14 ins.

Cromwell Mk III: as I said above, a Centaur I with Meteor engine fitted.

Cromwell Mk IV: Centaur III with 75mm gun and Meteor engine

Cromwell Mk IVw: as Mk IV but with an all-welded hull instead of rivets.

Cromwell Mk Vw: as Mk IV but with all-welded hull.

Cromwell Mk VI: as Mk IV but fitted with 95mm howitzer in place of 6pdr for close support role.

Cromwell Mk VII: appliqué armour welding on front. 15½ tracks replacing 14 ins, stronger suspension, and final drive reduced to lower max speed to 32Mph (all previous Mks had max speed of 40 mph).

Cromwell Mk VIIw: Cromwell Mk Vw modified as above.

Cromwell Mk VIII: Cromwell Mk VI modified as above.

Sunday, 06 August, 2006  
Blogger ritsonvaljos said...

I've read a bit about 'Totalize' for my WW2 research, but not with the detailed background knowledge about tanks that some others obviously have! Looking through my various notes, books and maps about 'Totalize' from the Allied viewpoint it seemed that the first phase of 'Totalize', supported by RAF Bomber Command, went more or less as planned (five miles from start line). It was then it started to go wrong, but not purely due to the operational difference of tanks.

As you obviously seem to be aware, the bomber support by the US 8th Air Force failed to recognise the correct targets leasing to several hundred Canadian and Polish casualties, a great tragedy. According to some accounts in the museums in France, some Canadian units opened fire on the Americans. Whether this was true or not I can only go from the statements in the museums. Certainly it cannot have helped the objective firing on your own troops.

The view among the accounts I've read seemed to be that by this time in early August 1944 the German tank commanders were going to fight to the last man in this sector. No ground was going to be given up unlike further west against the Americans. I think you can see why when you see what happened after Operation 'Tractable' that followed 'Totalize': German Army Group B was basically trapped in the Falaise pocket.

According to what I read, Allied WW2 tanks were not generally designed for night fighting. Then when the 28th Canadian Armoured did advance at night, they got lost and they then received little or no support in the subsequent tank battle, losing I believe about 40 tanks and 240 men.

It is easy to be wise after the event, of course. Many of the Germans in this operation were experienced commanders and desperate to fight to the death for the last piece of ground if need be. So it was going to be difficult to deal with this sort of enemy.

During the war, not far from my home at Lowther Estate, Cumbria they tested out night fighting capabilities for tanks. It was all hush hush. A lot of locals living nearby still remember these exercises. I'd have to look it up properly but the main idea seemed to be the use of laser lights to temporarily (perhaps!) blind the enemy in the dark and thus disable any effective defence. Apparently it never came to fruition because by then it was getting towards the end of the war and therefore would not be needed. It was also felt it might not be 'quite the done thing' for the Allies to use tanks in this way. I think they also felt that perhaps this kind of weapon would have worked in the North African desert but not as well in the European arenas, where the fighting was by then taking place.

By coincidence, the then heir to the Lowther Estates, Hon James Lowther, who later became Earl of Lonsdale, served in an Armoured Regiment in WW2 (East Riding Yeomanry) and was in Normandy. He passed away only a few weeks ago.

It was interesting to read all your comments about the different types of tanks.

Sunday, 06 August, 2006  
Blogger Tomcann said...

Joseph -
it was a well worn phrase that when the Luftwaffe came over - the British ducked ....When the RAF went over - the Germans ducked but when the USAAF went over ... everybody ducked.There is no question that the waiting for the USAAF and their bad marksmanship cost the second wave of Totalize the advantage gained by the night march of the first wave and prolonged the closure of the Falaise gap - plus Patton's idiotic phrase that he would drive the British into the sea for another Dunkirk.
The Canadians were not averse to having a go at the Americans at the slightest opportunity this is why they, and as we were in the Canadian Corps - we were also banned from entering Naples after a ding dong... they tried it on also at Rome but Alex put his foot down.It was not unusual to see a notice reading - "This is a Canadian liberted town"- the Americans trod warily around those notices.

Monday, 07 August, 2006  
Blogger Tomcann said...

Peter = am I right in thinking that the Covenanter begat the Crusader which begat the Cromwell which begat the Comet;; and the Churchill begat the Chieftain which begat the Conquerer which begat the Challenger 1 & 2 ???
The poor old Valentine had no begats and it was a good little tank complete with pop gun !

Monday, 07 August, 2006  
Blogger Peter G said...

First can I respectfully correct an anachronistic mistake in case others seek information on our blog.

I refer to this: the main idea seemed to be the use of laser lights to temporarily (perhaps!) blind the enemy in the dark and thus disable any effective defence.

The laser (Light Amplification by Stimulated Emission of Radiation) wasn't invented until well after WW2. It was an offshoot of the maser, which was not discovered until April 1954, with the first public mention being made in June. The first laser was produced at the Hughes Research Laboratories in Malibu, California in 1960.

Yes Tom, you are quite right about the provenance of the Cromwell, it had a long history stemming back to the 1930s (NOT the 1920s as I said in my previous comment). This is the full sequence:

Cruiser Tank Mk I (A9): Production started in 1937. A9s equipped some regiments of armoured divisions in France right up to Dunkirk. The were also used in the Western Desert until 1941. They had both inadequate armour and low speed and were fitted with a 2 pdr gun.

Cruiser Tank Mk II (A10): This was simply an increase in armour achieved by bolting on extra plates to the Mk I. They were regarded as stop-gaps pending the planned introduction of the Christie suspension.

Cruiser Tank Mk III (A13): this variant was the important breakthrough and initiated the long run of cruiser tanks with Christie suspension. This requires a word of explanation. It stemmed from the designs (strangely largely unsuccessful in America) of a brilliant American designer, J. Walter Christie. The man responsible for the introduction of his designs to British tanks was Lt Col G. Le Q. Martel, Assistant Director of mechanisation at the War Office. In September 1936 Martel attended the Soviet Army autumn manoeuvres and was very impressed with the Soviet BT tank (the T-34 prototype), which the Russians had developed after buying some of Christie's prototypes rejected by the Americans. When he returned to London Martel expressed the opinion that a tank vastly superior to the A9 (then under development) could be produced by using Christie type suspension and a lightweight engine like the Liberty used in Christie prototypes, perhaps not realising that the Russians had rejected the Liberty engine in favour of the far more powerful M-17-T, V-12, giving 500bhp at 1,650 rpm. For the Mk III the Liberty V-12 340 hp engine (an old American aero engine of WW1) was adopted as standard, built under licence by Nuffield. These Cruisers Mk III were used by 1st Armoured Division in France in 1940 with a few used by 7th Armoured Division in Lybia in 1940-41.

Cruiser Tank Mk IV (A13 Mk II): this was essentially an uparmoured Mk III. The extra armoured plating was mainly on the nose and turret front with plating on the sides. They were used in France and North Africa as above, but also for training in Britain.

Cruiser Tank Mk V 'Covenanter' (A13 Mk III): From the Covenanter all British cruiser tanks were named with a name beginning with C (for 'cruiser'). For this the armour was beefed up and the profile lowered by fitting a Meadows Flat-12 engine. It was disastrous due mainly to over-heating breakdowns never solved. 1,771 were made but this variant was never used operationally, though it equipped UK-based armoured divisions for training until 1943 and some were sent to the Middle East for training whilst others were converted to bridgelayers.

Cruiser Tank Mk VI 'Crusader' (A15): Given Britain's perilous position in 1940 this was a rushed job put into production without adequate development trials, particularly for desert operations. Nevertheless, it became the principle British tank from early 1941, first going into action near Capuzzo in June 1941. It was in every major desert battle including Alamein in October 1942, though by then in the process of being replaced by American-built M3s. The Germans respected the Mk VI only for its speed, but it was no match for its principal opponent, the PzKw III with its 50mm gun. The German 55mm, 75mm, and 88mm guns had no trouble picking off Crusaders.

Cruiser Tank Mk VII 'Cavalier' (A24): with this variant things went from bad to worse. The armour was increased but the Liberty engine, although beefed up, couldn't really cope with the increased weight. Breakdowns were even worse. Fortunately the army was spared, no Cavaliers were issued to front line armoured forces. They were used for training as gun tanks, but in 1943 half of them were converted to OP tanks for artillery regiments in armoured divisions in NW Europe in 1944-45.

Cruiser Tank 'Centaur' Mk VIII (A27L): this is an interim variant designed as a stop-gap until the Rolls-Royce Merlin engine was ready. Initially fitted with the 1917 Liberty engine in an engine compartment designed for the Merlin engine and fitted with a Merritt-Brown gearbox to allow re-engining to Merlins at a later date. About 950 were completed with the Liberty engine, 80 of them destined for an heroic role as close support models with a 95mm howitzer in place of the 6pdr gun. These were used in the Normandy D-Day landings by the Royal Marines Armoured Support Group, giving covering fire from the sea from LCTs and then landing with guns blazing over the beaches on 6 June 1944. I recollect a relative of one of these brave men recorded this incident in the BBC Archive; I shall have to locate it. The remaining Centaurs were either converted to Cromwells as the Meteor engines became available in 1943, re-designated Cromwell X, later Cromwell IIIs, or were used for training in their original form. Others were converted for special purposes, including AA tanks, ARVs, OP tanks, and Dozers, all used in NW Europe 1944-45.

Cruiser Tank 'Cromwell' Mk VIII (A27M): no, not a typo, both Centaurs and Cromwells were Mk VIIIs. A27L stood for Liberty engined, and A27M Merlin engined. As Frank says, they were one and the same. For variants of the, finally successful Cromwell see my previous Comment.


British and American Tanks of World War Two by Peter Chamberlain and Chris Ellis (Silverdale

Books, 2004). This is the finest book I know and I have quoted from it liberally above, albeit skimming it

lightly. It is chock full of detail on all variants, some 2,000 with over 500 detailed photos.

World Encyclopedia of the Tank - An international history of the armoured by Christopher Chant

(Sutton Publishing, 1994)

The Illustrated Encyclopedia of Military Vehicles by Ian V. Hogg and John Weeks ( Burlington, 1980)

Monday, 07 August, 2006  
Blogger Tomcann said...

Frank mentions a few engines - some of which made him cry - but he never mentions the Meadows flat 12 cylinder which we had all through our Mark 1V Churchills - never gave us a moments problem - except the day I "helped' our driver to clean all four carburretors.
WE couldn't understand - at the end of the day - when the engine wouldn't start - until I found all four float chambers drying in the sun on top of the turret !
I didn't live that down for quite a while !

Monday, 07 August, 2006  
Blogger Tomcann said...

Well Frank - all I can say is that your'e Army service was deprived of the glories of a Churchill with a Meadows flat 12 - even when we forgot about the five cans of M&V heating up - and bursting - that engine never quit and Charlie Bailey - our driver from Keighly - never had a worry about it not performing when he pushed the button - no matter the conditions - and sometimes they were bad - it started first time and kept going.
Bit heavy on petrol though at about four gallons to the mile - but then - it was cheaper than to-day !In fact - I don't remember paying for it !!!! Come to think of it also - we never broke a track !

Monday, 07 August, 2006  
Blogger Peter G said...


So far as I can judge from the data, all Churchills, from Mk I to Mk XI and the 24 specialised variants, were powered by Vauxhall-Bedford twin-six (i.e., V-6, 12 cylinders), over-head valve, water cooled, 350 hp, petrol engines.

Despite being judged by many as a weak point, the engine was never upgraded although from Mk VII onward Churchills had heavier suspension and an improved gearbox.

In total 5,460 Churchills were built by a production group consisting of Broome & Wade, Birmingham Carriage and Wagon, Metropolitan Cammell, Charles Roberts, Newton Chambers, Gloucester Railway Carriage, Leyland, Dennis, and Harland & Wolff. But all were under the 'parentage' of Vauxhall.

There is a good article here, although the full description in Chamberlain & Ellis, the top tank historians, runs to twelve pages of small print.

Would a Meadows flat-12 280 hp drive a heavy Churchill? Even the standard Bedford twin-6 at 350 hp was considered insufficient by many, especially for the later heavier Churchill specialised variants. The Meadows flat-12 was used successfully in the Tetrach light tank, but even an enlarged version (beefed up from 165 hp to 280 hp) fitted to the Cruiser tank Mk V Covenanter was a failure and none saw active service.

Tuesday, 08 August, 2006  
Blogger Tomcann said...

Peter -
as far as I can recall - the Churchill's we had in the 145th RAC in both Africa and Italy were all Mk 1V's fitted with Meadows flat 12's. The other two Battalions i.e 12RTR ans 48TH RTR of the 21st Tank Bde might have had different versions as the 12th did have some Sherman's issued for the Cassino and Liri valley battles - when we were in reserve to 25th TB.
The only change we experienced was in the issue of one 95mm Petard for one tank in each squadron. No major change of engines was ever attempted or models as we had Churchills all the way through - again to my knowledge ! The Sherman's of the 12RTR didn't do very well as we encountered many of them - some still burning, they were well named as Ronson's !

Tuesday, 08 August, 2006  
Blogger Tomcann said...

Peter -
having now read the 12 page blurb on the A22 Churchill Mk1V - what can I say against the accumulatd wisdom of the experts - except to point out that their "mobility" column needs revising - OUR Regiment's Mk 1V always had MEADOWS Flat 12's - Charlie Bailey could make our "Decisive" belt along at 25 MPH on any good surface - for as far as 90 MILES in range on two tanks of petrol. This was proven in the last major scheme - Buster - in Scotland and NE England prior to embarking for Africa. Charlie was told off for speeding !

Tuesday, 08 August, 2006  
Blogger Peter G said...


This is a bit of a conundrum. You have a distinct memory of Churchill's powered by Meadows flat-12s, yet there is absolutely no record of this.

The limitation of the Churchill was indeed the engine. We glibly mention the Vauxhall-Bedford twin-6, the designation sounds impressive just like that, but in fact it was a custom-designed patched job, essentially a pair of six-cylinder Bedford truck engines lying on their sides and married to a common crankcase.

This petrol unit, as I said earlier, developed only 350 hp (261 kW) giving the Churchill a distinctly modest power to weight ratio. In the first year this proved very unreliable made worse by poor engine installation.

The War Office had insisted on a readily accessible engine compartment, but this failed to materialise and the entire engine had to be removed for even minor problems (perhaps Frank could comment on this). Development and service experience gradually eliminated the engine problems and this in turn reduced the adverse effect of the less than satisfactory engine installation. Ultimately, however, the Churchill became a very reliable tank.

I still can't understand why you would fit a Meadows flat-12 280 hp engine to a heavy Churchill when it was specifically designed to take the more powerful and readily available Bedford twin unit.

The other problem is that the engine's power was transmitted to the rear drive sprockets by a flexible transmission system which made it more easier and more precise to drive than other British tanks. But this was designed to link to the Bedford twin-6 unit. It remained in service until 1952, well into Frank's shift.

The major upgrade was, of course, the Churchill Mk VII, but after going into great detail of the upgrade (too lengthy for here). Christopher Chant says "The engine remained unaltered, and the tank's maximum speed was reduced from 16 to 12.75 mph (25.75 to 20.5 km/h); this was a governed speed produced by a gearbox with lower ratios to avoid overtaxing the strengthened suspension".

Tuesday, 08 August, 2006  
Blogger Tomcann said...

Peter -
without recorded facts we shall get nowhere as I am adamant that we had the Meadows flat 12 - readily accessible except for the main electrical junction below the engine - which seldom gave us trouble as we had all the electics in the roundabout on the turret floor - we cleaned it too often of five cans of M& V to be mistaken.

Tuesday, 08 August, 2006  
Anonymous Anonymous said...

Sorry Peter and others, I do beg your pardon for a possible misleading application of the term 'laser' about the secret tank manouvres on the Lowther Estate towards the end of WW2. I did say in the earlier posting I would have to look it up properly! The way I put it is basically how you might hear locals who remember those times describe what went on, no doubt with later terminiology perhaps influencing how it is now described.

I've got a video I bought about wartime Cumbria. There is a section about the tanks testing out these lights, but nothing ever came of the tests.

I might try and look up a little bit more Lowther in wartime in the local library, if there is anything. I had looked up what I posted about 'Totalize'. You are right to make the point about the correct wording. Sorry.

Tuesday, 08 August, 2006  
Blogger Tomcann said...

Dear anonymous -

You will find that the 2nd East Riding Yeomanry were a part of 27th Armoured Brigade in support of an Infantry bde of 3rd Inf Division which landed on Sword Beach on D day taking part in many Battles namely Goodwood.
You will further know that the 3rd (Iron) Division was the Division which Monty was given out of unemployment just after the war started.
It should also have been involved in the Husky landings at Sicily but was replaced by the 1st Canadian Inf Division.

Wednesday, 09 August, 2006  
Blogger Peter G said...

'Anonymous' no need to apologise, especially in this blog. We all make mistakes including, I know you'll find it hard to believe, me. :)

For example, earlier I said

Cruiser Tank 'Centaur' Mk VIII (A27L): this is an interim variant designed as a stop-gap until the Rolls-Royce Merlin engine was ready. Initially fitted with the 1917 Liberty engine in an engine compartment designed for the Merlin engine and fitted with a Merritt-Brown gearbox to allow re-engining to Merlins at a later date.

Merlins? I meant the Meteor. It's the same engine, but the Merlin was the aircraft version and the Meteor was a Merlin with all expensive light alloy components removed and replaced with steel, stronger and cheaper for tanks.

As for the Meadows flat-12 saga I am completely stumped. On the one hand we have Tom's firm recollection of having one in the field fitted to a Churchill, and presumably not an isolated one, and on the other hand a series of technical specifications not listing this.

I had best set out the little I know about the Meadows Flat-12 DAV engine.

It started off as the Meadows 12 cylinder 165hp engine designed specifically for the ultra-light tank, the Tetrach, with a crew of two with an all-up battle weight of 16,800lbs. For this, the Meadows modest power output was ample giving the Tetrach a top speed of 40 mph.

It was next tried on the Cruiser Tank Mk V Covenanter (A!£ MkIII) This came about because it was decided to greatly increase the armour of the Cruiser MkIV. But given the extra weight it was also decided to lower the profile.

However, all previous cruisers (Mk I to Mk IV) were powered by Nuffield Liberty V12 engines. Whilst these engines gave adequate power, 340 hp, their height was too much for the lower profile of the Covenanter. (Their height can be seen in the photo here. For this reason it was decided to re-bore the Tetrach Meadows low profile horizontally opposed V-12 engines and fit them to the Covenanter, becoming the Meadows Flat-12 DAV rated at 280 hp. The driver's position was relocated to the right, but that left no room for radiators in the engine compartment. As a result, the radiators were moved to the front of the vehicle. The unusual arrangement, combined with rushed design process, resulted in serious problems with engine cooling which were never solved. As a result no Covenanters were issued although 1,771 were made.

Some of these were converted to bridgelayers. That, so far as I am aware, was the end of the Meadows in tanks. From then on engines of greater power were used, either by reverting back to the Nuffield Liberty V12 340 hp in the Crusader, Cavalier, and Centaur or, from the Cromwell onward (Challenger, Avenger, Comet, Centurion, etc), the 600 hp Rolls-Royce Meteor V-12. The power of the Meteor was sufficient for these tanks, ranging from the 61,600lbs battle-weight of the Cromwell to the hefty 107,520lbs of the Centurion, although the latter had a supplementary 8hp Morris engine to charge the dynamo and work the cooling fans.

The Churchill (from Mk VII) had a battle-weight of 87,360lbs. Incidentally, an interesting fact is that the Churchill, along with contemporary British tanks, was built to meet British railroad loading gauge restrictions and was thus too narrow to take the larger turret required for the 17 pdr gun! I wonder how many lives that cost?

Wednesday, 09 August, 2006  
Blogger Tomcann said...

Interesting comment regarding the Churchill being too narrow owing to the Railroad gauge being as it is at 4'8*....this goes away back in history when the Romans were building their roads based on their chariots wheels which were approx 4'8'wide - this caused ruts and so in order to keep the rest from breaking - the standard was set at 4'8" ... this prevailed when the British came up with the Trains etc.
The same British engineers were called upon by the Americans to lay out their railroads... again at 4'8' - and this is why the boosters of the various space rockets are so small when the Americans would like them to be even bigger ...

The problem ... these boosters are made in Utah.. which means they have to come through the Rocky Mountains and the rail gauge is ... again 4'8".. or the original width of the Roman Chariots of two horses asses !

Wednesday, 09 August, 2006  
Blogger Peter G said...

This is an interesting story, I did a Google search for "railway gauge roman chariots" and got over 41,000 hits! I read a few, all without exception talk of "the Roman military chariot".

The trouble is that there was no such thing as a Roman military chariot. In Roman times, say from about 100 BC, it was already a curious item of antiquity (spanning from 1,800 to circa 650 BC) and much as European aristocrats ostentatiously had themselves depicted in full armour or jousted in armour in the age of gunpowder, so the Roman aristocracy regarded the chariot. For them the chariot was purely a ceremonial vehicle used in triumphs for a victorious general (imperator) and in arena races.

Ruts were caused by heavier regular traffic. The state post (cursus publicus) was conveyed all the way by a single messenger who travelled in a carriage with horses changed at post-stations (not by relays of mounted messengers as is commonly thought, the amount of post was far too heavy for that). But this wasn't by chariot, there is no such vehicle as a Roman military chariot. There was an express post (cursus velox) and a slow post (cursus clabularis) consisting of waggons (clabulae angariae) drawn by oxen for transporting bullion, the families and baggage of officials and soldiers, and sometimes the soldiers themselves.

The vehicles used in the express post were a heavy coach (reda), a post-chaise (currus), and a gig (cisium or birota), the reda could carry seven or eight, the birota two passengers. It was the heavy vehicles which over time caused the ruts and it made sense to restrict the axles to the width of the ruts so that the wheels could run in them and thus avoid breakages. But the ruts were quite wide as I have seen and examined for myself in Pompeii.

As for Robert Stephenson, I do think the story is true. I first heard it in 1949 in Newcastle and I was shown the ruts Stephenson had used to decide the gauge, but I now cannot recall where that was. I think it was at a point along Hadrian's Wall. Be that as it may, long after the Romans had been forgotten it still made sense for medieval carters to travel in the ruts rather than having one wheel in and one wheel out leading to broken axles.

The mine tramways were also probably set by this standard so we are now stuck with 4'8½". This is a pity, because had Brunel's gauge of 5 ft been adopted we would travel at higher speeds and much more comfort, the characteristic swaying on a train journey is caused by the carriages overlapping the standard 4'8½" track on either side. So by a twist of fate the Churchill didn't get its 17pdr gun. How strange the world is!

Wednesday, 09 August, 2006  
Blogger Peter G said...

No need to regularly decoke oxen, Frank. An ox is a decoked young bull, and it stays that way for life. :)

Wednesday, 09 August, 2006  
Blogger Tomcann said...

Frank - decoking horses etc - take a pail of gin and harpic - sends 'em clean round the bend and produces fantastic roses as you say

Thursday, 10 August, 2006  

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