Sherman with Rover Meteor engine

[Foo Fighter]

Packard begin producing Merlin engines in 1940 as a preparation to supplying european nations. As a paper exercise they decide to fit the engine to an M4 type tank. Lower hull and more power earlier, what would the result be and could it be ready with a better armour and gun for D-Day?

 

[riggerrob]

May I suggest the Allison V-1710 engine instead? Its 12, liquid-cooled cylinders were arranged in two banks spread 60 degrees apart. With 28 liters of displacement producing 800 to 1200 horsepower it competed directly with the 27 liter Rolls-Royce Merlin that birthed the Meteor tank engine.

It was in large-scale production when the USA entered World War 2 and was reliable. V-1710 was widely used in American fighter planes: A-26 Apache dive bomber, P-38 Lightning, P-39 Airacobra, P-40 Warhawk, P-51A Mustang, etc. By mid-war, P-51A was the fastest WALLIED photo-recon airplane at low altitudes. Allison provided plenty of high-altitude performance when mated with exhaust-driven turbo-superchargers in P-38 Lightnings, but turbo-chargers proved too bulky for single-seat fighters ... limiting high-altitude performance.

V-1710 was even trialed in the T-29 Super Heavy Tank. T-29 was too late to serve in WW2, but at 141,000 pounds, it made Tiger II look dainty and delicate and petite. Mind you that weight would have broken most bridges in Europe! Hah! Hah!
In practice, aircraft V-12 engines proved a nightmare for tank crews when they wanted to replace spark plugs, etc.

Both V-12 engines would have provided lower drive shafts - way down on the hull floor - to match the lower silhouette of Hellcat tank destroyer.

 

[Apophenia]

Packard begin producing Merlin engines in 1940 ...

By 1940, the Americans already had a modern V-12 engine with exactly the same displacement as the Meteor but built to US standards - the Ford GAA. Putting more work into adapting that V-1650 engine for tank use would seem like a simpler solution.

The beauty of the Meteor was that is made use of components that failed to make the grade for use in high-performance aircraft engines. As Riggerrob suggested, you could so the same with the Allison V-1710 without changing the timeline.

Unlike combat aircraft, tanks didn't need supercharging or especially high-compression. I suppose, that is why the otherwise-obsolete Liberty V-12 was built by Nuffields for tanks. Prior to choosing the Meteor, a tank engine based on the Kestrel was also considered. So, why not use older engines which already fit the bill?

If your object is a relatively modern US-built V-12 in the Sherman by 1940, what about the Curtiss V-1570 Conqueror? That engine had become an industrial 'orphan' after the Curtiss-Wright merger. For a what-if scenario, have the Conqueror tooling moved to one of the US auto-makers prior to WW2. No need to change the aero-engine timeline.

 

[Foo Fighter]

Thanks folks, lateral and diverse. I must learn to be less limiting in this respect. Sounds very good and I wonder why these paths were those not taken.

 

[Elan Vital]

Producing the Meteor in the US might have been valuable...for the British, since it would increase the supply for Cruiser tanks while remaining compatible with British-produced engines.

One limitation for Sherman is that the transmission is only good for 550hp. Accounting for losses to accessories and cooling, this means that any engine beyond 650-700 hp will not be useable in this tank. Both the GAC and V-1710 could probably be downrated to that setting however. For the M6 Heavy tank and T2X series though, either of these engines would have been fine at a higher power setting.

The Curtiss D-12 was actually used in the T3E2 Christie tank, so the V-1570 might be suitable although it was not used anywhere near as long as the R-975 so didn't have the advantage of still being in service. The 1800 cu successor designed in the 30s could also have worked, and both were very narrow engines which might be interesting if you want to fit accessories or fuel tanks on either side of the engine.

Radials were selected because they were air-cooled and somewhat light for the power they had, but the Army missed their inherent problems with width and height, the driveshaft, the torque and the oil and fuel consumption. V-1570 probably would have been better in the long run.

 

[Elan Vital]

Packard begin producing Merlin engines in 1940 as a preparation to supplying european nations. As a paper exercise they decide to fit the engine to an M4 type tank. Lower hull and more power earlier, what would the result be and could it be ready with a better armour and gun for D-Day?

After a conversation with British historian Ed Francis who just got a lot of archives, it turns out that Packard DID want to produce Meteors.
Ford also deliberately tried to sabotage British Meteor production by asking that machining parts for this engine be made low priority.

 

[riggerrob]

During World War 2, tank designers struggled to solve a variety of technical and tactical problems.
It was only after they solved problems with cross-country performance and reliability that they started to worry about how profile affected survivability. Soviets were early adopters of Christie's sloped armor, but it was 1943 before Germans introduced a sloped glacis plate on their Panzer 5 "Panther". American tank destroyers paid lip service to sloped armor, but since most of their designs were based around the tall Sherman hull, they made little progress until the "clean-sheet" M18 Hellcat tank destroyer with a completely new hull wrapped around a modified (radial-engined) Sherman drive train.
British tank designers only introduced a sloped glacis in the final months of the war: Centurion.

 

[Foo Fighter]

The Meteor in the Cromwell had an output of 550bhp so would be at the upper end of the transmission ability to manage but might have been possible.

 

[jstar]

During World War 2, tank designers struggled to solve a variety of technical and tactical problems.
It was only after they solved problems with cross-country performance and reliability that they started to worry about how profile affected survivability. Soviets were early adopters of Christie's sloped armor, but it was 1943 before Germans introduced a sloped glacis plate on their Panzer 5 "Panther". American tank destroyers paid lip service to sloped armor, but since most of their designs were based around the tall Sherman hull, they made little progress until the "clean-sheet" M10 Hellcat tank destroyer with a completely new hull wrapped around a modified (radial-engined) Sherman drive train.
British tank designers only introduced a sloped glacis in the final months of the war: Centurion.

Hellcat was M18. M10 had GM 6406 twin diesel engine.

 

[Elan Vital]

The Meteor in the Cromwell had an output of 550bhp so would be at the upper end of the transmission ability to manage but might have been possible.

What the transmission cares about is net hp at the transmission inlet. Any engine loses a couple dozen hp to cooling and other accessories, so you could even push to the 620hp of early Centurion with no issues. In practice you'd use the Cromwell version during the war.

 

[Kingsman]

Apologies for reviving this thread after more than 2 years, but I am looking into the "Packard Tank Engine" proposed for the UK in 1941 into 1942. I came across this while rummaging through the Dewar Tank Mission files in the UK National Archive.

The UK was never interested in re-engining the Sherman, although the US did experiment with various new engines inluding a V12 and a triple Lycoming flat-6. We were, however, looking for alternative engines for some UK tanks, notably the A12 Matilda - for which the White "Pancake 12" flat-12 engine was briefly considered, with White confirming that it could be adapted to fit. This might also have been an alternative for the A22 Churchill, which already used an adapted Bedford flat-12 commercial engine of 350 BHP, but does not seem to have been considered for this.

The only complete tank engine we sought to have made in the USA was the Nuffield tank version of the Liberty. However, US industry and officialdom would only manufacture the original US aero Liberty - which we did not want.

We did however buy a lot of compatible Liberty components from Vimalert, who were at one point breaking down Liberties to extract the usable parts: they had bought a bunch after WW1. Vimalert offered an 800BHP V12, as far as I can tell a marine engine not derived from the Liberty. Vimalert had much success with adapted Liberty engines in racing speedboats. But the UK was not interested. Which is perhaps odd because we were looking to push the Meteor to 900 BHP with supercharging. Which was never done: 820 BHP with fuel injection in the 69 ton Conqueror tank was as good as it got.

The Ford GAA was considered experimental and underpowered by the UK. But elswhere on this forum is a discussion about a Ford V12 tank engine for the UK (GAN or GAY), of which it is said that a dozen were made and shipped over but probably never installed in anything after a V12 Meteor-engined Cromwell outperformed a GAA-engined M4A3 Sherman in tests that were hardly fair. Also, it was not installation-interchangeable with the Meteor - which deems to have been a key requirement.

We did try to get Meteor components made in the USA, especially those like the crankshaft which were Merlin-compatible parts already in production in the USA by or for Packard. But the capacity and priority were not there to do this. Maybe this is the Ford conspiracy theory because we were definitely not interested in complete Meteors from the USA. Notwithstanding the improvements Packard had made to the Merlin in adapting it for assembly line mass production rather than Rolls-Royce hand building.

But then Packard popped-up with a proposal for an all-new V12 tank engine, in which the UK became very interested and at one point was looking for 4,000 of them for the Cruiser Tanks Mks VII and VIII: Cavalier, Centaur and Cromwell. 600-700 BHP was predicted. Supercharging to 900 also seems to have been proposed. It was suggested that it might be made in the UK if it could not be made in the USA. There was much to-ing and fro-ing over specifications, with the UK encouraging Packard to leverage R-R's 9 years of development experience with the Merlin and Meteor, and to consider incorporating as many Meteor-compatible parts as possible. But Packard persevered with the all-new design idea, which worried the UK somewhat.

Even so they sought US support for the War Production Board to approve the manufacture of 4,000 of them. Suggesting that the US might adopt it too. Then it started to go wrong when the UK requested US machine tools for Meteor engine manufacture and the response was that it would be better to supply machine tools for Packard engine manufacture to both countries. And Packard started being less forthcoming with information and engagement. I suspect this was a deliberate ploy to kill off Meteor and replace it with the Packard paper proposal. But 4,000 Packards would have meant the end of Meteor anyway unless it was retained for Centurion. 4,000 was enough for Cavalier, Centaur, Cromwell and Comet. This is where the Dewar files end, in February 1942.

Clearly the Packard V12 tank engine never saw the light of day, AFAIK not even in experimental form like the Ford V12s. But it would be good to know how and why the whole idea came to an end.

 

[Siberia]

Prior to choosing the Meteor, a tank engine based on the Kestrel was also considered.

IIRC they were looked at concurrently with the Kestrel able to generate 475 bhp on lower octane pool petrol, but that was less than the desired bhp/ton figure so they went with the Merlin as the Meteor. It's a shame they never investigated something like this sooner – although I don't know if there was the spare development capacity to do so without affecting work on the Merlin – than sticking with the Liberty or paired diesels.

 

[MrTopaz]

A fair amount of discussion of alternate tank engines is gone over in the Late War M4 Sherman Redesign thread, including this link posted by Pioneer which lists a bunch of upgrades, including a Chrysler built engine that seems to have the same displacement as the Curtiss Conqueror, though I’m guessing that’s just a superficial similarity.

 

[Elan Vital]

Apologies for reviving this thread after more than 2 years, but I am looking into the "Packard Tank Engine" proposed for the UK in 1941 into 1942. I came across this while rummaging through the Dewar Tank Mission files in the UK National Archive.

The UK was never interested in re-engining the Sherman, although the US did experiment with various new engines inluding a V12 and a triple Lycoming flat-6. We were, however, looking for alternative engines for some UK tanks, notably the A12 Matilda - for which the White "Pancake 12" flat-12 engine was briefly considered, with White confirming that it could be adapted to fit. This might also have been an alternative for the A22 Churchill, which already used an adapted Bedford flat-12 commercial engine of 350 BHP, but does not seem to have been considered for this.

The only complete tank engine we sought to have made in the USA was the Nuffield tank version of the Liberty. However, US industry and officialdom would only manufacture the original US aero Liberty - which we did not want.

We did however buy a lot of compatible Liberty components from Vimalert, who were at one point breaking down Liberties to extract the usable parts: they had bought a bunch after WW1. Vimalert offered an 800BHP V12, as far as I can tell a marine engine not derived from the Liberty. Vimalert had much success with adapted Liberty engines in racing speedboats. But the UK was not interested. Which is perhaps odd because we were looking to push the Meteor to 900 BHP with supercharging. Which was never done: 820 BHP with fuel injection in the 69 ton Conqueror tank was as good as it got.

The Ford GAA was considered experimental and underpowered by the UK. But elswhere on this forum is a discussion about a Ford V12 tank engine for the UK (GAN or GAY), of which it is said that a dozen were made and shipped over but probably never installed in anything after a V12 Meteor-engined Cromwell outperformed a GAA-engined M4A3 Sherman in tests that were hardly fair. Also, it was not installation-interchangeable with the Meteor - which deems to have been a key requirement.

We did try to get Meteor components made in the USA, especially those like the crankshaft which were Merlin-compatible parts already in production in the USA by or for Packard. But the capacity and priority were not there to do this. Maybe this is the Ford conspiracy theory because we were definitely not interested in complete Meteors from the USA. Notwithstanding the improvements Packard had made to the Merlin in adapting it for assembly line mass production rather than Rolls-Royce hand building.

But then Packard popped-up with a proposal for an all-new V12 tank engine, in which the UK became very interested and at one point was looking for 4,000 of them for the Cruiser Tanks Mks VII and VIII: Cavalier, Centaur and Cromwell. 600-700 BHP was predicted. Supercharging to 900 also seems to have been proposed. It was suggested that it might be made in the UK if it could not be made in the USA. There was much to-ing and fro-ing over specifications, with the UK encouraging Packard to leverage R-R's 9 years of development experience with the Merlin and Meteor, and to consider incorporating as many Meteor-compatible parts as possible. But Packard persevered with the all-new design idea, which worried the UK somewhat.

Even so they sought US support for the War Production Board to approve the manufacture of 4,000 of them. Suggesting that the US might adopt it too. Then it started to go wrong when the UK requested US machine tools for Meteor engine manufacture and the response was that it would be better to supply machine tools for Packard engine manufacture to both countries. And Packard started being less forthcoming with information and engagement. I suspect this was a deliberate ploy to kill off Meteor and replace it with the Packard paper proposal. But 4,000 Packards would have meant the end of Meteor anyway unless it was retained for Centurion. 4,000 was enough for Cavalier, Centaur, Cromwell and Comet. This is where the Dewar files end, in February 1942.

Clearly the Packard V12 tank engine never saw the light of day, AFAIK not even in experimental form like the Ford V12s. But it would be good to know how and why the whole idea came to an end.

Very interesting. Maybe there are files from previous and later tank missions which could provide some more info or context?

Do you have the link to the search results on the national archives for the Dewar mission? I haven't found them myself.

 

[ArtosStark]

Notwithstanding the improvements Packard had made to the Merlin in adapting it for assembly line mass production rather than Rolls-Royce hand building.

The idea that RR Merlin’s were hand fitted and that Packard first adapted the Merlin design to mass production is a myth that refuses to die.

RR tolerance drawings show that their specifications exceed even modern automotive practice and exceeded contemporary practice on German engines (with their reputations for precision). RR managed to build over 100,000 engines in 4 factories, some newly set up before the war, using large amounts of unskilled labour (over 40% were women only taken on after the outbreak of war) and using components that came from multiple subcontractors mixed with the same components built in house. All fully interchangeable at least within their own mark, and for many parts across the whole series.

This was not an exercise is hand craftsmanship.

Packard’s effort is truely impressive. But the reason it’s impressive is often lost in all the “British hand built vs American mass produced” BS. They managed to very accurately reproduce an engine from different drawing types and than they were used to and adapting different processes to the same design, using British standards (including thread types) from an ocean away and make them so closely to spec that they were effectively interchangeable. They then were able to not only produce almost 60,000 of them, but were able to continue to develop the engine in their own way somewhat independently.

That is seriously impressive and speaks to the quality of Packards work. They did have RR help in this. Among other things RR’s chief production engineer led a team that was attached to Packard and the stress of the work is considered a major contributor to his death in the US before the end of the war. But it was nonetheless a massive undertaking by Packard which speaks to their ability.

 

[Apophenia]

Does anyone know the displacement or weight of the Buffalo, NY-made 850 hp Stirling Admiral V12s used in Fairmiles?

If not too heavy, might a land vehicle-modified Admiral have provided an American engine alternative to Nuffield Liberty V12s?

 

[Kingsman]

There are no earlier or later files that I can find. Believe me, I looked. They start after the mission was created and finish before it was wound up. The National Archive search is a bit old and clunky and it is only an index: no digitised content. You have to go there (West London) and eyeball material. The file series is WO 185/40 to 185/61. But all that will tell you is the file titles. They cover the period from July 1940 to January 1942. There is a Ministry of Supply file series but they begin some time later.

The problem here is that archiving and retention was, and still is, down to people at desk level to decide. I worked for UK MOD for 32 years and in some of my jobs I was responsible for signing off files for destruction, short-term and permanent retention. It could be as random as one person thought these were worthy of retention while others thought the preceding and succeeeding files were not. There are other files like the Tank Board Minutes that might have associated material but that will have to wait for another visit. Even from where I am in the UK I can't get there and back in a day by rail and have a full day there. I need to stay over. My first visit a few months back was an 8 hour round trip for 4 hours there....

The R-R vs Packard story continues and I suspect a lot of it has grown with the telling. Merlins may not have been hand-fitted (as in parts adjusted to fit) but factory images suggest they were at least partly hand-assembled. And some of it may be different language interpretations. In the UK we would usually consider "hand-fitted" to mean that parts were individually adjusted to fit if they did not fit on first presentation, whereas we would most usually say "hand assembled" for exactly that: assembly by hand. Ford GB were also building Merlins, although Ford in the USA declined. Meteors after the Mk1 were outsourced to other manufacturers, notably Rover (who acquired the design and converted a factory in Nottingham for it) but including Morris, Meadows and later Jaguar.

Talking of threads, for the Packard engine it was suggested that both US and UK built engines would adopt US threads and that US industry would supply all the studs, nuts, bolts, taps and dies. R-R assistance was proposed for Packard but seemingly declined, which was not understood. Likewise, Packard were reluctant to send an engineer to the UK to explain their workings or be involved in installation design. Also not understood. It is clear that the UK had serious reservations about Packard's ability to produce an all-new engine interchangeable with the Meteor in a few months without help, despite which we were pushing for it to be manufactured. Which makes me wonder if they were actually leveraging their 4M2500 marine engine, of which nearly 13,000 were made during WW2.

The reason no attention was paid to e.g. Kestrel derivatives sooner was that the UK War Office made a conscious decision in the 1930s NOT to develop specific tank engines but instead to rely on commercial engines. Hence why we went to war with the A9, A10, A12 and Valentine powered by feeble AEC or GM 6-cyl truck/bus engines and the A11 powered by a Ford car/truck V8. The A13 was the first tank powered by an engine at least adapted for tank use, the Liberty V12 aero engine as modified by Nuffields for tank use. This later went into the A15 Crusader, A24 Cavalier and A27L Centaur but suffered with reliability issues because of the old underlying design. The Meadows DAV flat-12 was a purpose-designed tank engine used only in the A13 Covenanter - an unsuccessful unreliable design never fielded - but never used again. The A22 Churchill had a flat-12 made from 2 Bedford flat-6 bus engines. We were in an engine mess.

R-R were working on the Meteor as early as 1941 although it doesn't see operational combat use until June 1944 (and survived until 1993 in Centurion AVREs!). Roy Rowbotham at R-R saw the potential for a more modern tank engine derivative of the Merlin in the same manner as the Liberty. Why not the Kestrel? Pressurised cooling for a start, not practical in tanks especially not in desert climates. And not enough power. Kestrel only got to about 700 BHP continuous with supercharging and aviation-grade petrol. And different parts. Many Meteor parts were identical to those for Merlin while Kestrel was AFAIK completely incompatible. And already an old design, dating back to 1927. Although it did at least have one-piece cylinder blocks, R-R's first.

 

[Kingsman]

I believe the Sterling Admiral may be the "800HP gasoline engine" proposed by Vimalert but rejected by the UK for unspecified reasons.

According to The Old Marine Engine Discussion Board, the Sterling Admiral may have begun life as this Vimalert engine with only 400BHP as advertised in 1930. But I'm not convinced. This Vimalert engine is clearly an adapted Liberty, which Vimalert were known for, whereas the sterling - while visually similar - is visibly different and supposedly a Sterling original design.

With the UK talking to Vimalert about Liberty parts perhaps they felt they had a way in with the Sterling engine in a way that Sterling did not. I can't see that they had an 800BHP version of the Liberty: that would have been remarkable.

But it was a hefty lump and it may have been recognised as the Fairmile engine. Marine engines were not being considered for tank use by the UK and I wonder if that perhaps explains why Packard were being coy about the genesis of their proposed engine if indeed it was based on the 4M2500

 

[Apophenia]

...According to The Old Marine Engine Discussion Board, the Sterling Admiral may have begun life as this Vimalert engine with only 400BHP as advertised in 1930. But I'm not convinced. This Vimalert engine is clearly an adapted Liberty, which Vimalert were known for, whereas the sterling - while visually similar - is visibly different and supposedly a Sterling original design...

Agreed. Sterling may have designed their Admiral as a market replacement for the Vimalert Liberty derivatives but the former does seem to have been an original design.

Just to be clear, I was suggesting a potential Sterling Admiral tank engine purely in the spirit of this Alternative History and Future Speculation thread.

 

[Kingsman]

Just to be clear, I was suggesting a potential Sterling Admiral tank engine purely in the spirit of this Alternative History and Future Speculation thread.

And I believe that it may well have actually been the engine proposed by Vimalert. Another 800 BHP normally-aspirated petrol/gasoline V12 would be a very strange coincidence. Vimalert and Sterling would have known each other from the marine engine world and as I said, Vimalert may have felt that they had a better chance of selling to the UK than Sterling did. Having failed to sell the UK their remaining stock of original Liberties, which they ended up breaking for parts. Vimalert certainly did not have an 800 BHP engine of their own and there was no way they were going to squeeze that much BHP from anything based on a Liberty.

Nuffield did manage to take their Liberty version to 420BHP for the A24 Cavalier but with consequent effect on already poor reliability. More twisted crankcases...... Lord Nuffield was determined that R-R were not going to oust him as the UK supplier of Cruiser Tank engines, but his engine simply could not compete with the Meteor in power, torque or reliability. The day of the separate-cylinder engine relying on crankcase rigidity was over. Curtiss had showed the way with the D12. But that pig-headed insistence meant that the 500 Cavaliers - described as entirely useless and purchased only to keep Lord Nuffield quiet - were the last Cruisers Nuffield built: never used. The related successor A27 Centaur/Cromwell was taken away from them and given to Leyland, with R-R working some magic on cooling as well as the Meteor engine. Although about 1,800 Centaurs still used the Liberty engine in its older 375BHP form. But were not considered combat-worthy: training only. Although 80 did see action with the Royal Marine Armoured Support Group for 2 weeks after D Day, the survivors being passed-on to Canadian and Free French units. Liberty-engined Centaurs were later converted to tankdozers or sold to Greece and Portugal.

 

[Apophenia]

... Although 80 did see action with the Royal Marine Armoured Support Group for 2 weeks after D Day, the survivors being passed-on to Canadian and Free French units. Liberty-engined Centaurs were later converted to tankdozers or sold to Greece and Portugal.

On the Canadian side of that story ... the Royal Canadian Artillery would receive twelve 95 mm Centaurs from X Armoured Battery, RA. The 1st Canadian Centaur Battery, RCA was formed in Normandy specifically to operate these SPs with training done while the British battery was still in action. The transfer took place on 17 Aug 1944 (assisted by 15 x Royal Signals members and 1 x REME gun tech on loan for the purpose).

RCA planners intended the existence of 1st Canadian Centaur Battery to last 3-to-4 weeks (or until the operational need ended). The unit went into action on 17 August 1944 near Troarn (about 14 km east of Caen). 1st Canadian Centaur Battery came out of action on 31 Aug and, between then and 02 Sept, the Centaurs went to Ordnance Stores (thence, presumably back to British Army control).

There don't seem to be any RCA complaints about Centaur reliability ... but, then again, the vehicles were only in Canadian Army service for less than 2 weeks.

-- https://milart.blog/2017/05/31/1st-canadian-centaur-battery-rca/

 

[Kingsman]

The Centaur IV CS was essentially used as SP artillery, so lots of time in static locations. They were fitted with indirect fire dial sights. The role of RMASG Batteries after landing was to team up with a designated parent RA Battery and act as artillery. Many did, and ended up not firing a shot. Their ballistics did not match that of the 25pdr gun - much shorter range and no zoned cartridges - so they could not take part in most 25pdr shoots. There were few if any calls for shoots from the LCTs on the run in to the beaches, their original intended role. Some Troops who had lost their Troop OP/command Sherman went off looking for trouble, notably H Troop, and did good work in direct infantry support. The 95mm HE shell was comparable to the 25pdr. There was also a HEAT round which could take out even a Tiger at 2,000m. In addition to the Canadian Battery, the Free French had a Centaur Battery around Calais.

The Centaur was one of more than 6,000 British-built tanks in WW2 that were not considered operationally deployable. Mostly because of 15,000-odd Shermans reaching us - the U boats and Luftwaffe claimed about 2,000 more during shipping. 1,700 Covenanters, 500 Cavaliers, about 1,500 of 1,820 Centaurs, and over 600 of the 2,960 Cromwells. Most of the early Churchill Mk I and IIs that were never upgraded to 6pdr or 75mm guns were never used operationally either, other than a handful with the Canadians again at Dieppe and a few that made it to Italy fitted with dual 3" CS howitzers (turret and hull) to make up for the lack of 95mm CS Churchill Vs.

That being said, these tanks were not wasted as they all provided valuable training. If you can operate a Covenanter, you can operate a Crusader - apart from different driving and maintenance. Same with the Cavalier and Centaur vs Cromwell. 1,700 Covenanters for training meant 1,700 more Crusaders with operational units. The best tank we had at the time, which is not saying a lot.

 

[Kingsman]

Steering us back to engines, the Vimalert marine engine pictured in the advertisement - used by the US Army as the V-1150-1 - was a normally aspirated 45 degree V12 of 1,145 CID delivering 400BHP. The Sterling engine matches Vimalert's proposed 800BHP exactly.

Reading my photos of the Dewar files in more detail it becomes clear that the proposed Packard engine was a derivative of their 4M2500 marine engine and not a new design. It is decribed as a 60 degree V12 of 1,500 CID with 5 3/8" bore x 5 1/2" stroke developing 425BHP at 1,800rpm and 550-600BHP at 2,500 running 75 or 80 octane fuel through Holley pressure carburettors And "will resemble Packard 25,000 cubic inch (!!) engine in Mosquito Boat but will have cast iron crankcase and valve housing". I presume the reference to 25,000 CID is a typo for the 2500 engine. An overhaul life of 600 hours was anticipated.

 

[Elan Vital]

Steering us back to engines, the Vimalert marine engine pictured in the advertisement - used by the US Army as the V-1150-1 - was a normally aspirated 45 degree V12 of 1,145 CID delivering 400BHP. The Sterling engine matches Vimalert's proposed 800BHP exactly.

Reading my photos of the Dewar files in more detail it becomes clear that the proposed Packard engine was a derivative of their 4M2500 marine engine and not a new design. It is decribed as a 60 degree V12 of 1,500 CID with 5 3/8" bore x 5 1/2" stroke developing 425BHP at 1,800rpm and 550-600BHP at 2,500 running 75 or 80 octane fuel through Holley pressure carburettors And "will resemble Packard 25,000 cubic inch (!!) engine in Mosquito Boat but will have cast iron crankcase and valve housing". I presume the reference to 25,000 CID is a typo for the 2500 engine. An overhaul life of 600 hours was anticipated.

View attachment 754074

It is notable that prior to this proposal, it is the US-built Meteor which didn't pan out. It is interesting to think that if not for personal/organisational reasons, the Ford tank engine may never have happened and that instead either US-Meteor or that Packard engine might have been pursued. In much the same way Packard got to build Merlin in the US because Ford sr. refused production of that engine in his US facilities.

At a glance the Packard proposal is just as powerful as the historical Meteor (if a little more power-dense), though IIRC, if achieved, the 600 hour overhaul life touted here might exceed that of the Meteor. I do wonder if the squarer bore-stroke ratio of the Packard would yield any notable benefits, as if I recall this was deemed more suitable in postwar engines.

 

[Kingsman]

I do wonder if the UK missed a trick by not pursuing US production of the Meteor as the Merlin was already in production there. I found no evidence of any thinking along those lines, although the sourcing of Merlin-Meteor common parts like crankshafts was explored in 1941 and found to be impractical for lack of suitable capacity. Although I have encountered people who believe that Meteors were made in the USA.

I have seen it said that H Ford Sr somehow arranged to have access to the Merlin drawings while they were held by US Customs and had copies made and that the Ford GAx family was derived from that. I have no idea if that is correct. Wiki certainly says it to be so.

The GAA and GAF V8s were perfectly satisfactory engines AFAIK. 500BHP from 1,100 CID was nothing to be ashamed of and about 25,000 were made. The V12s were less successful, but because of lack of application rather than any technical or performance deficiency. Although as I mentioned above there is a thread on this site which proposes that some (12?) V12s were made and shipped to the UK as a potential Meteor/Liberty alternative. The still-born and hopeless Valiant assault tank was proposed to have a Ford V8 engine for production.

The UK clearly saw the Packard engine as a replacement for both Liberty and Meteor and believed it could have US application. A V12 was trialled in a Sherman but seemingly offered no advantage. However, a V12 in the M26 would have been a good idea - i.e. the M46 - and it has always eluded me why the M26 appeared with essentially the same V8 as the Sherman despite being 50% heavier when V12s has been used in the heavier T2x and T3x prototypes and it was clearly known that Germany was using 650-700BHP V12s in tanks of similar weight (Panther).

But if Packard had a line tooled for the 4M2500 perhaps that was the key reason for its apparent preference. That engine was still needed by US Navy and Army for fast boats, but in smaller numbers than the aviation need for Merlins, potentially leaving spare capacity. Setting up a new line or re-tooling the 2500 line would perhaps have been counter-productive. And machine tools were another general supply bottleneck with the UK requesting them under Lend-Lease as well as the burgeoning US need. Using what you had would be an advantage.

 

[Apophenia]

... the proposed Packard engine was a derivative of their 4M2500 marine engine and not a new design. It is decribed as a 60 degree V12 of 1,500 CID with 5 3/8" bore x 5 1/2" stroke developing 425BHP at 1,800rpm and 550-600BHP at 2,500 running 75 or 80 octane fuel through Holley pressure carburettors And "will resemble Packard 25,000 cubic inch (!!) engine in Mosquito Boat but will have cast iron crankcase and valve housing". I presume the reference to 25,000 CID is a typo for the 2500 engine. An overhaul life of 600 hours was anticipated.

That 27 Oct 1941 telegram is describing something more akin to Packard's 3A-1500 rather than the larger 4M-2500. Dating back to 1927-29, the Packard 3A-1500 (1,530.4 cid) matches the quoted specs exactly - 5 3/8" bore x 5 1/2" stroke (with articulated rods); delivering 525 hp @ 2,100 rpm (in Jan 1929 trials). The xA-1500 and xA-2500/xM-2500 were closely related (sharing some parts) which probably explains that "resemble" remark.

So, I don't where that leaves us. I'm not aware of any maritime derivatives of that 3A-1500 aircraft engine. Did Dewar (or Usher) just get the specs muddled? Or was Packard actually proposing a tank powerplant derived from the more compact 3A-1500 engine?

No mysteries as to why Henry Ford Sr. may have had access to Merlin drawings. As early as 1940, Ford factories in France were scheduled to license-build Merlin for the Armée de l'Air. The following year, Ford's previously-idle plant at Trafford Park, Manchester also started cranking out licensed Merlins.

 

[Kingsman]

Your knowledge of Packard engines is greater than mine. I guess I assumed the 4M2500 because I knew about it and it seemed to fit. I did not know about the 3A1500. The comment about hundreds of engines having been used reliably before 1930 sounds more like the 1500, as does the proposed power output. But the "mosquito boat" comment and the "25,000 CID" error clearly point to the 2500. As you say, there is no sign of a 3M1500. Yet the bore and stroke in the telex are wrong for the 2500 as you say and the power output of the 2500 was very much higher, even allowing for supercharging and high-octane fuel. Although the Meteor only delivered about 60% of the power of the least powerful Merlin and only about 30% of the most powerful. So by extrapolation a supercharged high-octane 1,200BHP 4M2500 might be expected to drop to the suggested 550-600BHP without supercharging and on lower octane fuel.

Unless I am much mistaken the 3A1500 was still essentially an evolved son of Liberty design whereas the 4M2500 was more of a Liberty cousin. And I've only just noticed that the 4M2500 was also still a separate-cylinder engine. Knowing that to be a Liberty weakness in tanks and that Meteor was a stronger cylinder-block design I am surprised that we saw that layout as being acceptable. Maybe the cast iron crankcase was seen as a remedy. IIRC the Nuffield Liberty still used an aluminium crankcase prone to distortion and never thought to switch materials. Coincidentally the matching gearbox for the Crusader tank was also aluminium-cased and proposed US manufacture led to a request to switch to cast iron. Nuffield were clearly keen on aluminium despite its strategic importance while R-R switched Meteor to cast iron from aluminium.

Other telexes show some confusion about designations and details of equipments, so a mix-up between 1500 and 2500 series engines is certainly not impossible.

 

[Kingsman]

Here is the next telex about the Packard proposal with more detail. But to confuse the issue further it clearly mentions cylinder blocks as adopted for the Merlin and other Merlin-compatible parts. Which does not match either 1500 or 2500 series engines as they were at the time. "Fortunate" similarity between Packard's proposal and "Merlin tank" (i.e Meteor) is noted at the foot of p2. Were they proposing some sort of 1500-Merlin hybrid?

 

[Kingsman]

And then we get to this in November, which muddies the water further. Suggesting that the Packard was only seen up to this point as a Liberty replacement. The proposed bore and stroke change here are the same as the Ford GAx at 5.4" x 6". Neither 1500 nor 2500.

 

[Kingsman]

Then at the end of December 1941 we have these, which seem to put an end to any hopes of Packard-Meteor compatibility. And introduces the idea of going to Ford for what is clearly the GAA, which we clearly do not favour: "too small" and "highly experimental". I wonder if this is the genesis of the UK V12 Fords covered elsewhere on this forum. Interesting that the 27 Dec telex in noted for "Robotham action" - R-R's chief designer and the moving force behind Meteor.

 

[Kingsman]

Then In January 1942 we get to this before the file sequence ends abruptly.

 

[Scott Kenny]

I do wonder if the UK missed a trick by not pursuing US production of the Meteor as the Merlin was already in production there. I found no evidence of any thinking along those lines, although the sourcing of Merlin-Meteor common parts like crankshafts was explored in 1941 and found to be impractical for lack of suitable capacity. Although I have encountered people who believe that Meteors were made in the USA.

I could see them being made from US-made Merlins that were crash recoveries.

 

[Kingsman]

I don't know that any Meteors were made from crash recoveries. Only the Mk I Meteors were Merlin conversions, still with the alloy block etc. Largely because R-R did not have the capacity to produce something much different, which is why they were looking initially for sub-contractors and then to offload the design when they got a sniff of Rover's work on gas turbines for Power Jets. Transition to the cast iron block and the "real" Meteor only happened once production had been transferred to others, notably Rover's new facility in Nottingham. Those converted engines were non-airworthy ones, but it isn't really clear why they were not airworthy.

It is not impossible that they could have been returned damaged engines. It seems likely as I would like to think that any factory QA failures would be re-worked. Returned engines could have been scavenged for conversion parts, but I believe that was already happening at Station or Maintenance Unit level. MUs could certainly rebuild engines on new blocks etc. Assuming they could get the parts. Stations theoretically had spare engines. Crashed aircraft parts were usually returned to MUs for repair or scavenging unless it was clear that there was nothing worth scavenging. And if there were enough USAAC aircraft crashing to feed a tank engine conversion line then there was a more fundamental problem to address.........

 

[Elan Vital]

The GAA and GAF V8s were perfectly satisfactory engines AFAIK. 500BHP from 1,100 CID was nothing to be ashamed of and about 25,000 were made. The V12s were less successful, but because of lack of application rather than any technical or performance deficiency. Although as I mentioned above there is a thread on this site which proposes that some (12?) V12s were made and shipped to the UK as a potential Meteor/Liberty alternative. The still-born and hopeless Valiant assault tank was proposed to have a Ford V8 engine for production.

The UK clearly saw the Packard engine as a replacement for both Liberty and Meteor and believed it could have US application. A V12 was trialled in a Sherman but seemingly offered no advantage. However, a V12 in the M26 would have been a good idea - i.e. the M46 - and it has always eluded me why the M26 appeared with essentially the same V8 as the Sherman despite being 50% heavier when V12s has been used in the heavier T2x and T3x prototypes and it was clearly known that Germany was using 650-700BHP V12s in tanks of similar weight (Panther).

Sherman didn't benefit as much from the V12 as the M26 did because its suspension wouldn't be able to use the extra power to weight-ratio quite as well. At the same time, the VVSS Sherman wasn't deemed capable to take much extra weight (before M4A3E2) so the extra power couldn't really be used to maintain mobility at higher weights either. That said, a M4A4 was tested with the 650 Chrysler A65 which was very useful, so a better Packard V12 or Ford V12 may still have been a practical option. The Ford V8 also had a 60° bank angle which is not great for balance with that cylinder layout, the V12 didn't have that issue. With the M4A3E2 and the HVSS suspension Shermans which were substantially heavier, such an engine might have been useful as well. The V12s did require the extended hull of the M4A4 however.
In fact, the M4A4 itself could have certainly benefitted from one of the V12s if sufficient excess production could be obtained. You save an enormous amount of weight and space while increasing power, maintenance becomes easier and you can in turn use that freed space for fuel, easier access or accessories.

Packard V12 is overall worse than the Ford (heavier and less powerful), but thanks to the use of iron instead of aluminium parts, it is much cheaper and easier to manufacture with that automobile equipment. Expanding production of the Ford (V8) proved extremely difficult so it didn't manage to become the standard engine as desired. Had the US-UK gone through with the Packard as the eventually standard tank engine in 1942, it may have been a more practical proposition in spite of its more limited power potential.

The V8 certainly was a very strange choice for the T2X family of medium tanks, especially as they became heavier with T25/M26. The whole point was to move away from Sherman's ideas, yet the opportunity wasn't taken to have a genuine quantum upgrade in power from the start. Either the 600-650 hp Packard or the 750 hp Ford V12 would have been much more suitable and may even have avoided some breakdowns caused by insufficent power, on top of making the M26 a true late war medium/battle tank like the Panther and Centurion.

Let alone the T28/95 superheavy tank which kept the V8 with a way greater weight!

 

[Kingsman]

900BHP was still an aspiration and supercharging was being considered. It is mentioned. But it is unclear if this is in the context of Packard or Meteor, or both. Although the need for 900BHP is questioned.

The T95/28 with the V8 GAF at 95 US tons (86 tonnes) was just barking. The poor thing could barely move! The T29 at least got the V12 GAC with 750BHP for its 70 US tons (64 tonnes). And trialled the Allison V-1710, rated at 1,000 BHP in aircraft form. The T30 went for another brand with the Continental AV-1790 with 810BHP to move its hefty 82 US tons (74 tonnes). T32 went back to the GAC for its 60 US tons (54 tonnes). T34 went with the Continental again for its 79 US tons (72 tonnes). So the US was certainly looking to expand its tank engine horizons.

Then there was the experimental Chrylser A65 V12 with 575BHP trialled in M4E3. And the GM V8-184 diesel in the M4A2E1. Its parent 16-184 X16-cyl marine engine with 1,200 supercharged BHP was recommended for consideration for AFVs over 60 US tons but was never thus used. I'm sure there was a triple Lycoming flat-6 trial setup too. But the apparently-promising Packard didn't get a look-in. And the less said about the radial diesels the better........

 

[Apophenia]

I could see them being made from US-made Merlins that were crash recoveries.

Well, that would be somewhat akin to making use of substandard Merlin parts put into a new block for Meteor production.

But, as the correspondence shows, 'recycling' was not the goal of the British procurement team. Rather, they were reminding their US-based counterparts that the real objective was to make full(er) use of Detroit's automotive capabilities to provide superior tank engines for the British war effort.

 

[Scott Kenny]

Well, that would be somewhat akin to making use of substandard Merlin parts put into a new block for Meteor production.

But, as the correspondence shows, 'recycling' was not the goal of the British procurement team. Rather, they were reminding their US-based counterparts that the real objective was to make full(er) use of Detroit's automotive capabilities to provide superior tank engines for the British war effort.

Right. recycling wasn't the goal.

But it would give the "Meteor parts were made in the USA" some technical accuracy.

 

[Kingsman]

But it would give the "Meteor parts were made in the USA" some technical accuracy.

Officially, none were. At least not up to the end of January 1942. By this time the US War Production Board was in charge of allocating industrial capacity to production needs according to their view of priority. Production of new components for UK-manufactured equipment was generally not given a high priority unless it was something already in production and expansion was feasible without affecting anything else. So the simple-looking idea to have more Merlin crankshafts made in the US, even just the un-machined castings, when these were already being made in quantity was refused. That part was apparently compatible between Packard and R-R Merlins and Meteors.

I suspect that any damaged engines in the USA would be repaired or scavenged in the USAAC system, as in the RAF. And in the UK the USAAC and RAF operated separately and so were operating their own individual repair lines. I can't see that Packard Merlins would have been shipped back to the USA or to R-R. So I cannot conceive that any US-produced Merlin parts found their way into any Meteor Mk I engines. Digging further, it seems these early Meteors used some non-airworthy production parts rather than being completely non-airworthy engines. A subtle but important difference. Again, I don't know what would make a part non-airworthy but still usable. Meteors were less stressed in some respects as they did not run constantly at or near max power and were not blown. But were more stressed in other respects as they spent a lot of time accelerating and decelerating, although with stronger crankcases and blocks.

 

[CaptianNemo2001]

May I suggest the Allison V-1710 engine instead? Its 12, liquid-cooled cylinders were arranged in two banks spread 60 degrees apart. With 28 liters of displacement producing 800 to 1200 horsepower it competed directly with the 27 liter Rolls-Royce Merlin that birthed the Meteor tank engine.

It was in large-scale production when the USA entered World War 2 and was reliable. V-1710 was widely used in American fighter planes: A-26 Apache dive bomber, P-38 Lightning, P-39 Airacobra, P-40 Warhawk, P-51A Mustang, etc. By mid-war, P-51A was the fastest WALLIED photo-recon airplane at low altitudes. Allison provided plenty of high-altitude performance when mated with exhaust-driven turbo-superchargers in P-38 Lightnings, but turbo-chargers proved too bulky for single-seat fighters ... limiting high-altitude performance.

V-1710 was even trialed in the T-29 Super Heavy Tank. T-29 was too late to serve in WW2, but at 141,000 pounds, it made Tiger II look dainty and delicate and petite. Mind you that weight would have broken most bridges in Europe! Hah! Hah!
In practice, aircraft V-12 engines proved a nightmare for tank crews when they wanted to replace spark plugs, etc.

Both V-12 engines would have provided lower drive shafts - way down on the hull floor - to match the lower silhouette of Hellcat tank destroyer.

The V-1710 was plausible in the M4A4.

When the V-1710 was considered for Tank use (T29) in July 1945 it was expected to produced 830 bhp. The study was undertaken by GM. However, by September 1945 the Ford V12 is also considered with power of up to 1100 hp on 80 octane fuel. This is then scrubbed a bit by January 1946 with the Ford V12 on the outs.

The Ford GAC V12 and Chrysler A65 V12s were intended for the M4A4s. Thus if you can fit the Ford in you should be able to stuff the 1710 in. Although personally its kinda silly with the stock transmission limited to about 550 hp from testing done during the war. You would have to install one of the automatic transmissions onto the M4, which was tested, to really get use out of the bigger engine.


British Army Staff (AFV) Situation Report Number 36 July 18th 1945 Para 204 page 97 _ 178
British Army Staff (AFV) Situation Report Number 37 August 18th 1945 para 210 page 96 _ 152
British Army Staff (AFV) Situation Report Number 38 September 18th 1945 para 112 page 45 _ 102
British Army Staff (AFV) Situation Report Number 41 January 18th 1946 para 7 page 5 _ 016 017

 

[CaptianNemo2001]

Sherman didn't benefit as much from the V12 as the M26 did because its suspension wouldn't be able to use the extra power to weight-ratio quite as well. At the same time, the VVSS Sherman wasn't deemed capable to take much extra weight (before M4A3E2) so the extra power couldn't really be used to maintain mobility at higher weights either. That said, a M4A4 was tested with the 650 Chrysler A65 which was very useful, so a better Packard V12 or Ford V12 may still have been a practical option. The Ford V8 also had a 60° bank angle which is not great for balance with that cylinder layout, the V12 didn't have that issue. With the M4A3E2 and the HVSS suspension Shermans which were substantially heavier, such an engine might have been useful as well. The V12s did require the extended hull of the M4A4 however.
In fact, the M4A4 itself could have certainly benefitted from one of the V12s if sufficient excess production could be obtained. You save an enormous amount of weight and space while increasing power, maintenance becomes easier and you can in turn use that freed space for fuel, easier access or accessories.

Packard V12 is overall worse than the Ford (heavier and less powerful), but thanks to the use of iron instead of aluminium parts, it is much cheaper and easier to manufacture with that automobile equipment. Expanding production of the Ford (V8) proved extremely difficult so it didn't manage to become the standard engine as desired. Had the US-UK gone through with the Packard as the eventually standard tank engine in 1942, it may have been a more practical proposition in spite of its more limited power potential.

The V8 certainly was a very strange choice for the T2X family of medium tanks, especially as they became heavier with T25/M26. The whole point was to move away from Sherman's ideas, yet the opportunity wasn't taken to have a genuine quantum upgrade in power from the start. Either the 600-650 hp Packard or the 750 hp Ford V12 would have been much more suitable and may even have avoided some breakdowns caused by insufficent power, on top of making the M26 a true late war medium/battle tank like the Panther and Centurion.

Let alone the T28/95 superheavy tank which kept the V8 with a way greater weight!

the VVSS COULD take the extra weight... the US Army TOLD the UK that it could. But, a big but, that the UK could have extra side armor (1.5 inches to make it 3 inches) or additional armor on the front. But that they could not have both. I'll find the note its from 1942.

It can go up to around 92,000 lbs as there was a proposed M4A3E2 with additional armor at that weight using VVSS. That said, it is severe abuse. HVSS didn't hold up well at 102,000 lbs with a T26 turret over 1000 miles. They lost a few springs and road wheels.

The BAS Reports are not user friendly and I have been poking away at them for several years.
===============================================
>>"The V8 certainly was a very strange choice for the T2X family of medium tanks"<<

Devers wanted it in everything. Its why you see it being shoved in T14, the T20, and even the M18(specs drawn up) as well as in UK designs. There was a bit of a snag. It wouldnt be refined and decently reliable until mid 43 and production capacity was not great.
=
=
In March of 1943 Ford was told to increase production of the Ford GAA Engine to 600 engines per month. The increase in production was approved by the Ordnance Branch while development of the engine continued to be ongoing. However the British noticed that critical materials such as aluminum was going to affect the program and as such commented that the substitution for aluminum with cast iron was far more likely now (March 1943) than ever before. The British then hoped that with the order to increase production it would provide for a stable outlook in production for the next six months. As a result they hoped that they would be able to negotiate with Armored Force and Ordnance for a percentage of the monthly production run and get assistance with starting an Ford GAA line in the United Kingdom. General Devers agreed, as representing the Armored Force, that month to lower his demands for universal application of the Ford engine to all types of Armored Vehicles[1].

---

[1] BAS 9 Page 011 Paragraphs 25 Ford V8 GAA March 1943.
=============================================


========================
======================== Timeline ==============
January 1943 360 per month engines or 11.6129 per day[1].
---U.S. Armed Forces were insistent in receiving Ford engines in M4A3 tanks and that, with production being low at 360 engines per month, the British and Russian requirements for the engine cannot be met until production reaches 2,000 engines per month. It was estimated that to bring production up to 2,000 per month would require, outside of Aluminum requirements, no less than 475 Machine Tools and 11,000,000 US Dollars for their purchase. A decision to make an Cast Iron model of the GAA was noted to ease Aluminum requirements for the engine but outside of the proposal nothing more was mentioned. This is all on top of the problem that Tanks and Tank Components have a lower priority compared to Aircraft. In view of all of the factors involved it was not expected that production would hit 2,000 engines a month before the end of the year .

February 1943 450 per month engines or 16.0714 per day. (Estimated in February 1943)[2]

---From February 1943 onwards 600 per month is wanted. The 600 in June represented the total output which Ford can manage with the machine tools they have bought to date (Feb 1943), but which have not yet been received in their entirety[3].

March 1943 300 per month engines or 9.6774 per day. (Estimated in February 1943)[4]

---March 1943 Ford told to increase production to 600 per month[5].
---From May 1943 onwards 600 per month is planned[6].

May 1943 Tank Automotive Center (TAC) estimates Ford could produce 750 engines per month.

---May 1943 Markland estimates Ford could produce 900 engines per month.

June 1943 600 per month engines or 20 per day. (Estimated in February 1943)[7]

---June 1943 Ford engine production cannot be stepped up quickly enough over the previously mentioned limit of 900 engines per month of which the Ford plant is capable[8].

October 1943 Production is 600 and it is planned that Continental may make some 200 engines per month[9].

January 1944 775 per month or 25 per day (31 day month). Planned to increase to 32 and then 40 per day. Lincoln factory[10]. 992 and 1,240 per month respectfully(Author).

February 1944 812 engines per month or 28 engines per day[11].
April 1944 1,040 engines per month[12].

---

[1] BAS 7 Page 014 Paragraphs 17 and 18 January 1943
[2] BAS 8 Page 020 Paragraphs 18 Ford V8 GAA Feb 1943.
[3] BAS 8 Page 020 Paragraphs 18 Ford V8 GAA Feb 1943.
[4] BAS 8 Page 020 Paragraphs 18 Ford V8 GAA Feb 1943.
[5] BAS 9 Page 011 Paragraphs 25 Ford V8 GAA March 1943.
[6] BAS 8 Page 020 Paragraphs 18 Ford V8 GAA Feb 1943.
[7] BAS 8 Page 020 Paragraphs 18 Ford V8 GAA Feb 1943.
[8] BAS 12 Page 035 Para 066 June 1943 (Production Figures)
[9] BAS 16 Page 042 Para APP A October 1943.
[10] BAS 18 Page 037 Para 052 Ford GAA January 1944.
[11] BAS 19 Page 035 Para 44 February 1944.
[12] BAS 21 Page 025 Para 29. April 1944