Advanced French Fighters vs 1942/1943 contemporaries (1 Viewer)

Elan Vital said:

One of the Morgenthau diaries also mention Anglo-French orders for the P&W R2800 dated May 22nd, 1940, the British ordered 600 of them and the French 230, to be delivered repespectively January-November and January-July 1941.

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This is all well and good to order engines, the problem is actually getting delivery.
So the British and French order 830 R-2800 engines.
P&W and Ford combined only made 1723 R-2800s in all of 1941. And 425 of them were made in Dec 1941, outside of the desired delivery dates.
Ford is delivering engines from a brand new factory (or incomplete) while P&W is building their R-2800s while almost doubling production of R-1830s from 1940 to 1941 and almost tripling their production of their other engines for trainers and low level transports (over 10,000 of these lower level engines built in 1941).
Now in 1942 P&W and Ford built about 11,800 engines and production increased by leaps and bound after that, but actual deliveries to either Britain or France in the summer of 1941?
US puts a hold on B-26 production?

Shortround6 said:

This is all well and good to order engines, the problem is actually getting delivery.
So the British and French order 830 R-2800 engines.
P&W and Ford combined only made 1723 R-2800s in all of 1941. And 425 of them were made in Dec 1941, outside of the desired delivery dates.
Ford is delivering engines from a brand new factory (or incomplete) while P&W is building their R-2800s while almost doubling production of R-1830s from 1940 to 1941 and almost tripling their production of their other engines for trainers and low level transports (over 10,000 of these lower level engines built in 1941).
Now in 1942 P&W and Ford built about 11,800 engines and production increased by leaps and bound after that, but actual deliveries to either Britain or France in the summer of 1941?
US puts a hold on B-26 production?

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Indeed, the order may have been based on production estimates that didn't pan out.

The people who designed the France Fights On timeline argued that the loss of French finances disrupted the US industrial buildup due to concerns about funding, and that the effect of France being in on US production are not insignificant, but unsure if that'd be enough to ramp up R-2800 production specifically to meet Allied and US orders alike.

Elan Vital said:

I have started to delve a little into the gargantuan depths of US digitized files at NARA on potential French docs, not much so far but the diaries of Henry Morgenthau talk about 1939-40 shenanigans, and there is something quite useful worth sharing now (I only studied a couple of the diary books).

Though not directly related to French fighters, I have found very useful reports from a US mission that went to France in June 1940 to visit French aero engine facilities and make some recommendations to the French about what could be improved. Somewhat over 100 pages worth of very useful info about existing and planned facilities, problems encountered by the French or conversely, rather good practices by some of them, recommendations. Of course, it was too late at this stage for France, but it gives a good idea of how what new capacities would have come online over 1940 and 1941 and possible changes that would have been implemented to ramp up production quantity and quality.

I have extracted the specific pages related to this, and gathered the reports here: US mission to the French aero engine industry 1940 – Google Drive

Some notable info from a cursory look:
- targets of 1800-1900 Gnome-Rhone and 1300 Hispano-Suiza aircraft engines per month to be reached at the earliest possible date in 1941
- anticipated production of the first GR-14R in late 1940, and 400 HS-12Z in 1940, so early industrialization efforts anticipated that year
- the new Hispano-Suiza and Fordair factories at Tarbes and Bordeaux respectively were tooled to effectively halve man-hours required for making a HS 12-cyl from the 2400-2700 man-hours at the H-S Bois-Collombes factory to 1400 and 1100-1200 at Tarbes and Bordeaux
- Extensive use of imported US materials, US practices and US tooling at Fordair, and other French factories also prefer US materials which are more uniform in quality than current French products.
- the trend towards shadow and underground factories from September 1939 onwards, esp G-R at Le Mans, Peugeot (G-R) near Bordeaux, Fordair and H-S in Bordeaux (with associated H-S underground assembly line at Jonzac) and Tarbes, H-S in an underground quarry near Paris; to insulate French production from bombing or WW1-style German territorial advance.

One of the Morgenthau diaries also mention Anglo-French orders for the P&W R2800 dated May 22nd, 1940, the British ordered 600 of them and the French 230, to be delivered repespectively January-November and January-July 1941.

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one of the big issues endlessly debated around here is whether GR-14R or HS-12Z were really viable designs that could go into production or were going to be stuck in 'production hell' for years before they could be produced.

The French seemed to believe they would be available, and the idea of getting some tools, parts and metals etc. from the US could help explain that.'

I tend to believe the French assumption that the 12Z etc. were in fact real and about to enter scale production.

And that in turn means that aircraft like the VG 39 and later upgrades of D.520 series and MS series, maybe even the Bloch as well, would have been much more competitive types.

Steamed_Banana said:

one of the big issues endlessly debated around here is whether GR-14R or HS-12Z were really viable designs that could go into production or were going to be stuck in 'production hell' for years before they could be produced.

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It's important to remember that the Gnome-Rhône 14R and the Hispano-Suiza 12Z were evolutions of the previous range, not entirely new models. In the minds of their designers, as well as their customers—I mean, their one and only customer, the French Air Force—they were intended to seamlessly replace the previous generation, which had already reached the entire end of its development (the 14N and 12Y).

The fact that they were evolutions—admittedly major ones, but evolutions nonetheless—of this previous range was reassuring regarding the rapid mass production that would follow the finalization of the designs. Thus, in the invaluable document revealed by Elan Vital (a huge thank !), the American experts state without hesitation that the 14R would begin deliveries at the end of 1940, that is, barely six months later. They add that two engines had already undergone extensive testing. Clearly, they weren't told that the design was already in its third stage (14R 00 - 02 - 04, and their "symmetrical" versions 01 - 03 - 05), the last of which incorporated a very important improvement: an axial-intake superchager. They also seem unaware that by June 1940, the 14R was already flying two prototypes (the Loire-Nieuport LN 10 and the LeO 455), and that a third, the Amiot 355, was just days away from its maiden flight—a flight that would be prevented by the Armistice of June 25, 1940.

The case of the 12Z is more problematic. American experts noted the profound disruption caused to the Parisian factories by the German offensive over the capital. Hispano's withdrawal to Tarbes was far more complex than that of Gnome-Rhône to Arnage (Le Mans). However, Tarbes would remain in the unoccupied zone, unlike Arnage. But it is likely that, "in a different conflict timeline," the 12Z would have entered mass production very quickly.

Therefore, there is no doubt that these two engines would soon have been able to equip French aircraft. The only real question is what their reliability would have been...

About numbers.... American experts seem to have been genuinely surprised by Gnome & Rhône's production rates, particularly for the cylinder heads, which were produced using a highly sophisticated casting process "in metal molds" and were being manufactured at a rate of 500 to 1,000 per day (!!!!). A figure probably unthinkable for American industry in June 1940.

This particular manufacturing process had been designed and patented by the Bruneau Frères foundry, as I explain in my article on "The Last Gnome & Rhône Engines."

Bretoal2 said:

About numbers.... American experts seem to have been genuinely surprised by Gnome & Rhône's production rates, particularly for the cylinder heads, which were produced using a highly sophisticated casting process "in metal molds" and were being manufactured at a rate of 500 to 1,000 per day (!!!!). A figure probably unthinkable for American industry in June 1940.

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While US industry had not reached that level yet saying it was unthinkable is pushing things.
Was G & R pushing out 1600 engines a month in May-June of 1940? 750 heads per day times 30 days divided by 14?
In June of 1940 P&W built 170 R-1830s, down from earlier production but in July they built 304 and in Dec they built 589 R-1830 engines. In June P&W had also delivered 388 other engines of 9 and 14 cylinders each. P&W was certainly thinking about producing engines on such a scale. Ford in Sept 1940 sighed a contract with the government to build a factory that could produce 800 18 cylinder engines per month. Wright was working on the plans for a new factory in Cincinnati to build the R-2600 BA engines. Took about 1 year to build and there were problems.

Bretoal2 said:

The fact that they were evolutions—admittedly major ones, but evolutions nonetheless—of this previous range was reassuring regarding the rapid mass production that would follow the finalization of the designs. Thus, in the invaluable document revealed by Elan Vital (a huge thank !), the American experts state without hesitation that the 14R would begin deliveries at the end of 1940, that is, barely six months later.

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Without knowing what the evolutions consisted of things are hard to judge.
P&W was on the 3rd (?) version of the R-1830 in the summer of 1940.
Wright had very few interchangeable parts between the R-1820 G100 and G200 series engines. (the 1100hp and 1200hp versions)
Wright was also working on the R-2600BA series engines in the summer of 1940 after about 1 year. They had worked on the A series engines since 1936 but aside from the bore and stroke there wasn't a lot interchangeable.

US did near miracles building and equipping factories on bare plots on land in 1940 and 1941. But even the US was not inexhaustible. At one point in 1940 Allison was short almost 800 machine tools despite having an A1A priority rating. Plans met reality. Getting the needed structural steel and cement on time to actually build the factories was not easy. Then you need electrical wiring and lighting all the rest of the stuff just to make the buildings.

Shortround6 said:

While US industry had not reached that level yet saying it was unthinkable is pushing things

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One has to read the whole sentence; I'm saying that this was unthinkable at the time the report was written (June 1940)—which doesn't mean that these figures weren't subsequently reached and exceeded—and later significantly exceeded—by American industry.

The figure put forward by the US Commission of 500 to 1,000 cylinder heads per day does indeed correspond to approximately 1,500 engines per month if we assume that all production was allocated to new engines, which is obviously an exaggeration since some was used for spare parts for maintenance, and very likely another portion was delivered to subcontractors like SNCM (Lorraine). The license for the Bruneau Frères process, described by the Commission as very advanced, had been granted only to Gnome et Rhône and not to French subcontractors (however, it had been sold, at least, to Manfred Weiss and Isotta-Fraschini).

Nevertheless, two things make this figure quite acceptable:

1) G&R manufactured 820 new engines in May 1940.

2) All observers note that production capacity was constantly increasing and would have reached very high levels if the first bombings of the Paris region hadn't disrupted everything in early June.

About evolutions...

I myself describe these developments as "major" because, starting from the original architecture, they modified many things without straying so far from it. So they were not really entirely new mechanical designs.

These changes were, I repeat, the following:

G&R, 14R vs. 14N:

- Significant increase in cooling surface area
- Two-speed supercharger and (14R 04/05) with axial inlet
- Crankshaft with central roller bearing in new crankcases
- Increased cross-sections for gas passages
- New lubrication system
- Various and numerous reinforcements
- Significant increase in inlet pressure

Hispano, 12Z vs. 12Y:
- New 4-valve cylinder heads
- "Differential scavenging" inlet
- Completely redesigned intake system, with the carburetors now positioned in the center of the V
- Direct injection starting with the HS79 Ter model
- Multiple reinforcements, notably on the Sarrazin dynamic-damped crankshaft and conrods
- Planiol-Szydlowki supercharger with increased capacity on certain variants

However, the dimensions remain the same (bore/stroke 146 x 165 mm or 150 x 170 mm) between the "parent" models, and the engines have roughly the same overall size. But the performance is completely different!

It does point to the effect of the Anglo French orders of 1939/40 in establishing a mass arms industry in America driven by Anglo French investments. Or at least their collateral in borrowing money to pay for it.

Without such mass orders it seems quite possible that America would be forced to go to war in 1942 with a 1938 sized arms industry and wait two years before they could roll out mass products. IOTL the expansion of the American arms industry relied upon the foreign market for growth.

Lend Lease was driven as much by American financial clever tricks to build up the American arms industry as it was to support Britain, France and latterly Russia.

Bretoal2 said:

One has to read the whole sentence; I'm saying that this was unthinkable at the time the report was written (June 1940)—which doesn't mean that these figures weren't subsequently reached and exceeded—and later significantly exceeded—by American industry.

The figure put forward by the US Commission of 500 to 1,000 cylinder heads per day does indeed correspond to approximately 1,500 engines per month if we assume that all production was allocated to new engines, which is obviously an exaggeration since some was used for spare parts for maintenance, and very likely another portion was delivered to subcontractors like SNCM (Lorraine). The license for the Bruneau Frères process, described by the Commission as very advanced, had been granted only to Gnome et Rhône and not to French subcontractors (however, it had been sold, at least, to Manfred Weiss and Isotta-Fraschini).

Nevertheless, two things make this figure quite acceptable:

1) G&R manufactured 820 new engines in May 1940.

2) All observers note that production capacity was constantly increasing and would have reached very high levels if the first bombings of the Paris region hadn't disrupted everything in early June.

About evolutions...

I myself describe these developments as "major" because, starting from the original architecture, they modified many things without straying so far from it. So they were not really entirely new mechanical designs.

These changes were, I repeat, the following:

G&R, 14R vs. 14N:

- Significant increase in cooling surface area
- Two-speed supercharger and (14R 04/05) with axial inlet
- Crankshaft with central roller bearing in new crankcases
- Increased cross-sections for gas passages
- New lubrication system
- Various and numerous reinforcements
- Significant increase in inlet pressure

Hispano, 12Z vs. 12Y:
- New 4-valve cylinder heads
- "Differential scavenging" inlet
- Completely redesigned intake system, with the carburetors now positioned in the center of the V
- Direct injection starting with the HS79 Ter model
- Multiple reinforcements, notably on the Sarrazin dynamic-damped crankshaft and conrods
- Planiol-Szydlowki supercharger with increased capacity on certain variants

However, the dimensions remain the same (bore/stroke 146 x 165 mm or 150 x 170 mm) between the "parent" models, and the engines have roughly the same overall size. But the performance is completely different!

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Reinforcement seems to be a big factor considering the Sauer version in Switzerland. Significant weight gain to the engine including some counterweights on the crankshaft right?

I also suspect that for the factories relying much more on US tooling, materials and techniques, the quality/reliability of the engines may increase even without any design changes. Fordair for HS 12Y esp

yulzari said:

Lend Lease was driven as much by American financial clever tricks to build up the American arms industry as it was to support Britain, France and latterly Russia.

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yulzari said:

Without such mass orders it seems quite possible that America would be forced to go to war in 1942 with a 1938 sized arms industry and wait two years before they could roll out mass products. IOTL the expansion of the American arms industry relied upon the foreign market for growth.

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The truth is probably somewhere in between your position and the US traditional narrative. French and British orders did pay for a lot of US aircraft factory expansion, but perhaps not as much as some people think it terms of percent. British and French paid for very little shipyard expansion in 1938-39-40. British and French paid for very little small arms production expansion or artillery expansion or even ammo expansion (not saying there were no ammo orders, just not new factories built to handle such orders). Not sure that France was interested in American tanks, Britain was or at least the idea of America building British designed tanks. This idea was flatly rejected by the Americans after the fiasco of WW I production when the US joined the war with all of it's factories tooled up for British and French (and Russian) weapons and the US had to either adopt foreign weapons or do without for months after declaring war. The US was happy to take British money for US designed tanks (with a bit of input from the British.
The whole "America would be forced to go to war in 1942 with a 1938 sized arms industry" bit rather ignores the US Navy re-armament plans. The USS Iowa and New Jersey were both ordered on July 1st 1939 and the Iowa was laid down on June 27th 1940.
It also ignores President Roosevelt's May 16th 1940 speech calling for the US to develop the capacity to built 50,000 planes a year and asked for $896,000,000 total for both air and other items. Congress voted some (most) of the money in June (?) and it was this that funded the Ford plant and the Packard Merlin production in part and a number of other projects/plants.
BTW this was a around 1 1/2 years after...................Jan. 12, 1939, he delivered a special message to Congress calling for strengthening of the Air Corps. Congress then authorized $300 million for 5,500 new airplanes.
It took a while for even the 1939 appropriation to kick in. That included the order for the 560 (524 actual aircraft and 36 as spare parts) P-40s but even the April 27th 1939 order tool a while as the first production P-40 didn't fly until April 4th 1940. Orders were placed for other fighters, bombers, recon and trainers.

Steamed_Banana said:

Reinforcement seems to be a big factor considering the Sauer version in Switzerland. Significant weight gain to the engine including some counterweights on the crankshaft right?

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Yes, about 30kg? just for the crank.

Bretoal2 said:

However, the dimensions remain the same (bore/stroke 146 x 165 mm or 150 x 170 mm) between the "parent" models, and the engines have roughly the same overall size. But the performance is completely different!

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Keeping the bore and stroke and overall size was actually rather common among engine builders. It is the little details that throw things into the ditch. Bristol used the same bore and stroke and overall size on the Hercules as the G&R used on the 14K,N and R. They just changed the valve system
Difference between a 1600hp R-2600 and a 1700hp R-2600????
New heads, new cylinders, new crankcase of steel instead on aluminum, new crankshaft, maybe new rods. and more and more. Just because your factory can make the 1600hp version doesn't mean you can switch over to the 1700hp version quickly.
For the 12Z it sounds like they are throwing out everything except the crankcase and cylinder blocks. And the usefulness of the existing crankcase and cylinder blocks on a 1300hp plus engine is somewhat doubtful. Possible, depending on desired engine life but who knows? If these parts are adequate for a 1300hp engine it means that they had been overbuilt for 850-1000hp engines all during the 30s. Perhaps a slightly different alloy can be used in the old molds or different heat treatment or ???.
Allison lucked into a new casting process developed by a pair of sculptors that was both stronger and a bit lighter and more accurate (tighter tolerances that needed less machining) than what ALCOA was providing. Allison and not started making their own large castings.
I have no doubt that Hispano could have made a 1200-1300hp engine in 1940 and 1941. The question is how quickly and what was the next step. The engine you are testing today will not show up in squadron service in numbers for around a year, if you are lucky.

Steamed_Banana said:

Reinforcement seems to be a big factor considering the Sauer version in Switzerland. Significant weight gain to the engine including some counterweights on the crankshaft right?

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Yes, that's the most obvious, but not the only one. "Reinforcement" also means thicker walls for the crankcases (especially the cylinder blocks, which, in the Hispano-Suiza system, withstand the same pressure as the pistons, or the central crankcase, which must resist the torsional forces of the crankshaft), or an increased diameter for some auxiliary shafts, etc.

Thus, dry weights:

GR 14N 48: 615 kg, 14R 04: 819 kg.

HS 12Y 45: 520 kg, 12Z 17: 690 kg. (approximately the same as the Hispano-Saurer YS-2, but the 12Z has no crankshaft counterweight !)

Shortround6 said:

I have no doubt that Hispano could have made a 1200-1300hp engine in 1940 and 1941. The question is how quickly and what was the next step. The engine you are testing today will not show up in squadron service in numbers for around a year, if you are lucky.

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The G&R 14P (this model incorporates all of the 14R improvements, except intermediate finning surface and tangential entry s/c) is introduced in 1937, as the "differential scavenging" patents by Louis Birkigt. The "1200 hp 4 valves" Hispano engines is running at the beginning of 1938.

The reason why almost nothing happened for 18 months afterward isn't a technical or industrial issue; the cause is solely the deplorable policies of the French government!

Shortround6 said:

Keeping the bore and stroke and overall size was actually rather common among engine builders. It is the little details that throw things into the ditch. Bristol used the same bore and stroke and overall size on the Hercules as the G&R used on the 14K,N and R. They just changed the valve system
Difference between a 1600hp R-2600 and a 1700hp R-2600????
New heads, new cylinders, new crankcase of steel instead on aluminum, new crankshaft, maybe new rods. and more and more. Just because your factory can make the 1600hp version doesn't mean you can switch over to the 1700hp version quickly.
For the 12Z it sounds like they are throwing out everything except the crankcase and cylinder blocks. And the usefulness of the existing crankcase and cylinder blocks on a 1300hp plus engine is somewhat doubtful. Possible, depending on desired engine life but who knows? If these parts are adequate for a 1300hp engine it means that they had been overbuilt for 850-1000hp engines all during the 30s. Perhaps a slightly different alloy can be used in the old molds or different heat treatment or ???.
Allison lucked into a new casting process developed by a pair of sculptors that was both stronger and a bit lighter and more accurate (tighter tolerances that needed less machining) than what ALCO was providing. Allison and not started making their own large castings.
I have no doubt that Hispano could have made a 1200-1300hp engine in 1940 and 1941. The question is how quickly and what was the next step. The engine you are testing today will not show up in squadron service in numbers for around a year, if you are lucky.

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I am curious about your reference to Alco. Is this the locomotive company?

Reluctant Poster said:

I am curious about your reference to Alco. Is this the locomotive company?

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Sorry, my mistake
ALCOA.

as can be seen, until very late in the war or after the war, Alcoa had a virtual monopoly on aluminum in the US.
If you were an engine manufacturer you pretty much (but not always) just did what Alcoa told to you to do to manufacture the desired parts out of aluminum.

Bretoal2 said:

The G&R 14P (this model incorporates all of the 14R improvements, except intermediate finning surface and tangential entry s/c) is introduced in 1937, as the "differential scavenging" patents by Louis Birkigt. The "1200 hp 4 valves" Hispano engines is running at the beginning of 1938.

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The trouble with the 14P is that without better finning (cooling) you are limited to the amount of power the engine will tolerate. This is why Wright went through so many versions of the R-1820.

This is just the changes in the cylinder head. There were a number of changes to the cylinder barrel. Being able to machine fins of the needed depth and narrow openings took a bit of doing. Just saying change the fins sounds easy. Now you want to make 750 heads a day?
Hercules engines were constant fight to add fin area to both the barrels and the heads, Hercules went through over 7 different head designs from the mid 30s to post war and all the Hercules head had to do was 4 things. Seal the combustion chamber, stay on the cylinder, hold the sparkplugs and not melt.
the last is a bit of an exaggeration, It has to stay cool enough that it doesn't act like a source of ignition for the fuel (hot spot) before the plugs fire.

Bretoal2 said:

The reason why almost nothing happened for 18 months afterward isn't a technical or industrial issue; the cause is solely the deplorable policies of the French government!

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granted the policies of the French government were deplorable. But there may have been a just a little finger pointing going on here.

It took about 1 1/2 years for Wright to get the 1700hp R-2600 to go from first bench test to 5th production engine out the door. and it took another 5 months to get production up to 45 engines a month, the 6th month saw 135 engines. Wright had some problems with this factory and there was a lot crap going on with faulty inspections and pay offs.
But that slow start up was pretty much standard for most factories. It took just over 1 year for that factory to go from 10 engines a month of 1900hp version to beating the production numbers of the 1700hp versions in the same factory. Blame it on the government or was there blame to go around?
It took about 1 1/2 years for P&W to go from 1st ground test of the 2000hp R-2800 to 5th production engine, and they didn't change anywhere near as much stuff. Production change over was very quick for P&W East Harford, Ford took a few months but then Ford was was only up to around 30% of desired production rate when they started the change over. It took Ford about 1 year to hit the production goal of 800 engines a month (they missed by 2 engines) after they started making the B series engines. That was about 2 1/3 years after starting work on the factory.
A lot of this stuff takes time. What was the actual production capacity of either French engine maker in 1937-38 in engines per month? how fast could they make additional factory space and hire/train workers?

As I have said many times, the US made it's fair share of mistakes or even more than it's fair share. The US poured millions of dollars into engine projects that went nowhere and should have been seen as being out on the doubtful side of things almost from the start or at least by 1940-41.
US officials/officers can only see so much and have to somewhat trust the figures the French are giving them and perhaps adjust somewhat by observation. The French seem to have rose tinted glasses on in the Spring of 1940 for more than aviation production.

Shortround6 said:

It also ignores President Roosevelt's May 16th 1940 speech calling for the US to develop the capacity to built 50,000 planes a year and asked for $896,000,000 total for both air and other items. Congress voted some (most) of the money in June (?) and it was this that funded the Ford plant and the Packard Merlin production in part and a number of other projects/plants.

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By the way, the Morgenthau diaries I was reading discuss the 50,000-plane program quite a lot.

British and French paid for very little small arms production expansion or artillery expansion or even ammo expansion (not saying there were no ammo orders, just not new factories built to handle such orders). Not sure that France was interested in American tanks, Britain was or at least the idea of America building British designed tanks. This idea was flatly rejected by the Americans after the fiasco of WW I production when the US joined the war with all of it's factories tooled up for British and French (and Russian) weapons and the US had to either adopt foreign weapons or do without for months after declaring war. The US was happy to take British money for US designed tanks (with a bit of input from the British.

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From what I have seen the Anglo-French only discussed planes, engines, maybe ships and materials (including powders) prior to the Battle of France and the Low Countries. The (Anglo-) French then made a huge program involving a major expansion of US capacity to provide ground weapons as well (artillery, small arms and tanks), sometimes involving French or British designs especially when US equivalents didn't exist (French 47mm AT), or designs that were produced in the US in WW1 and that were in use (1897 75mm, 1917 155mm howitzer).

The French had looked for either B1 Bis (preferably) or the SOMUA S40 to be produced in the US with or without US automotives and armament, and some info was shared for this purpose (to the Baldwin Locomotive company). The Americans wanted a B1 Bis to be sent over, but communications were too disrupted by late June. The M2 Light and Medium Tanks were discussed with estimated monthly production figures, but were rejected on the grounds of too little armor and a weak gun relative to the tank's mass (M2 Medium). That M2's automotives could be used to make the much more effective M3 Medium, Ram and M4 Medium wasn't expected.
However, if I go by what was said during a meeting of Henry Morgenthau with the French Arthur Purvis and Bloch-Laine, the Americans argued for basically "we will build a single design for the Americans and Allies alike and will accept advice/lessons from Allied technicians and soldiers, but won't make two distinct designs" which is pretty much what happened OTL.
Examples given were a common tank and supplies including 37mm M3 AT, 37mm AA and 90mm AA guns rather than European analogues. I'm not sure enough about the timeline to know how it lines up with the B1 Bis shenanigans.

If we go by the second paragraph, then the tank question would be close to OTL just with the British being joined by the French technicians to advise on the Ram and Sherman designs. But I don't think the French conclusions would be much different from British ones and even if there were, I'm not sure they can be implemented in either design (which are limited by the use of certain automotive parts and layouts).

What I'm not sure about is how events in Europe affect US involvement:
- are the massive orders for ground equipment only caused by the realisation of just how much gear will be needed now that high intensity operations started, regardless of how far the Germans advance? But if so, are there conditions where it is decided to build European gear in the US rather than US designs?
- are they instead only caused by the loss of the Northern industrial centers in France in May? If so how much capacity must be lost to trigger the huge orders in the US?

I suspect it's impossible to prove and is probably left to the preference of any alt-history writer.

Elan Vital said:

By the way, the Morgenthau diaries I was reading discuss the 50,000-plane program quite a lot.


From what I have seen the Anglo-French only discussed planes, engines, maybe ships and materials (including powders) prior to the Battle of France and the Low Countries. The (Anglo-) French then made a huge program involving a major expansion of US capacity to provide ground weapons as well (artillery, small arms and tanks), sometimes involving French or British designs especially when US equivalents didn't exist (French 47mm AT), or designs that were produced in the US in WW1 and that were in use (1897 75mm, 1917 155mm howitzer).

The French had looked for either B1 Bis (preferably) or the SOMUA S40 to be produced in the US with or without US automotives and armament, and some info was shared for this purpose (to the Baldwin Locomotive company). The Americans wanted a B1 Bis to be sent over, but communications were too disrupted by late June. The M2 Light and Medium Tanks were discussed with estimated monthly production figures, but were rejected on the grounds of too little armor and a weak gun relative to the tank's mass (M2 Medium). That M2's automotives could be used to make the much more effective M3 Medium, Ram and M4 Medium wasn't expected.
However, if I go by what was said during a meeting of Henry Morgenthau with the French Arthur Purvis and Bloch-Laine, the Americans argued for basically "we will build a single design for the Americans and Allies alike and will accept advice/lessons from Allied technicians and soldiers, but won't make two distinct designs" which is pretty much what happened OTL.
Examples given were a common tank and supplies including 37mm M3 AT, 37mm AA and 90mm AA guns rather than European analogues. I'm not sure enough about the timeline to know how it lines up with the B1 Bis shenanigans.

If we go by the second paragraph, then the tank question would be close to OTL just with the British being joined by the French technicians to advise on the Ram and Sherman designs. But I don't think the French conclusions would be much different from British ones and even if there were, I'm not sure they can be implemented in either design (which are limited by the use of certain automotive parts and layouts).

What I'm not sure about is how events in Europe affect US involvement:
- are the massive orders for ground equipment only caused by the realisation of just how much gear will be needed now that high intensity operations started, regardless of how far the Germans advance? But if so, are there conditions where it is decided to build European gear in the US rather than US designs?
- are they instead only caused by the loss of the Northern industrial centers in France in May? If so how much capacity must be lost to trigger the huge orders in the US?

I suspect it's impossible to prove and is probably left to the preference of any alt-history writer.

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A little-known episode in these attempts at European - and, in this specific case, French - production in the USA is the late 1939 attempt by the Wertheimer brothers, financiers of Coco Chanel but especially of Félix Amiot, to have the Amiot 351 manufactured in America. This attempt failed for various reasons.

This is regrettable because Amiot was probably the French aircraft manufacturer who had most thoroughly considered the industrial aspects of his aircraft production. A good illustration of this fact can be seen in this long sequence filmed primarily at his Cherbourg factory in the spring of 1940:


In 1939-1940, Félix Amiot filed numerous patents, a significant number of which concerned automated tooling (notably riveting and sheet metal bending machines).

Elan Vital said:

By the way, the Morgenthau diaries I was reading discuss the 50,000-plane program quite a lot.

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Thank you. I am not saying that the French and British orders did not help a lot.
What I object to and what you are not claiming, is that the Americans would have been using only the factories of 1938-39 in 1942 without French and British investment.
As noted earlier the US planned on ordering 5500 aircraft in 1939 of all types but most of them would not show up until 1940 or even later.
Yes the US palmed off a few older planes (or more than few) to the French and British but US 'readiness' was also degraded at times. The US allowed Buffaloes to go overseas while US Carriers were still operating biplanes. Curtiss was allowed to send Hawk 75s to France while the US was still waiting for some of it's P-36s. France never got it's Hawk 81s but the British did and the US let the British take them while the US transferred some of their places on the production line to later model Hawk 81s or Hawk 87s.
Might not have made any difference but an extra 50-100 Curtiss fighters in the Philippines on Dec 7th? More Hawk 81s scattered around (Panama canal) which would free up newer aircraft for actually combat.
The US's own investment of the summer of 1940 would not begin to pay off until the summer of 1941 in any real numbers and more likely into 1942 which is pretty much what happened.