French tanks to be built in the US

[Richard Anderson]

It probably had to do with what machine tools they had and how many they could modify or buy to do that specific job.

I'll have to look up the particulars, but one of the first machines adapted was one originally designed for milling multiple engine blocks at one time. I think it was used in the Fisher Body Works Grand Blanc Tank Arsenal.

[OpanaPointer]

Interesting, that last. Seems like ship builders could have given them a clue, the turret races for destroyers would seem to have been a greater challenge.

I'm not sure how well adaptable navy shipyards were for building tanks...and they were kinda busy building warships at the time.

Yeah, and technology is not transferable, so that's really a dead end, isn't it?

:roll:

[Richard Anderson]

Yeah, and technology is not transferable, so that's really a dead end, isn't it?

:roll:

Not the technology that is the issue; it's the logistics. Heavy machinery at a naval shipyard for milling really BIG turret races aren't much good when they are needed at Detroit or Schenectady to mill fair-to-middling size turret races. Ever wonder why it was so hard getting tungsten carbide allocated to the production of 3" and 76mm T33E4 HVAP? Because it was considered a critical material for machine tool production.

[OpanaPointer]

I never suggested transferring the equipment.

[Richard Anderson]

I never suggested transferring the equipment.

I understand that, but will repeat, the TECHNOLOGY was transferable as an intangible idea, but it had to be TRANSFERRED into PHYSICAL machinery.

[OpanaPointer]

Okay then.

[Andy H]

Hi

Thank you all very much for your input
Regards

Andy H

[USS ALASKA]

They had the skills, but did they have the production lines for that? (How many locomotive engines were they doing each year?)

The peak of Baldwin production was 3580 in 1918. And that was before their huge new plant was completed at Eddystone. Non-war peak was 2666 in 1906. Right before WW1 in 1913, they kicked out 2061. In 1932, the last year I have numbers for, only 65 rolled off the lines but this was because of greatly reduced demand during the Depression. What can be derived from these raw numbers I'm not sure. Baldwin was building locomotives from 10 to 430 tons on their lines. Their sales catalog from 1915 has 492 varieties to order from. While they were 'production lines', each engine group was different from those before it and those behind it. Hand crafted / each one unique sort of thing depending upon the wants and needs of the buyers. Not a (to badly misuse quotes from the past) "turn these things out like so many hot cakes / you can have any color you want as long as it is black" type of operation. I would hope that standardizing the line to a single flavor of tank would streamline production. Maybe as much as an order of magnitude but I have no facts or figures upon which to base that WAG.

Sources - The Baldwin Locomotive Works 1831 - 1915, by John K. Brown and The Locomotives Baldwin Built, by Fred Westing

Cheers,
USS ALASKA

[OpanaPointer]

Good information, sir. Thank you.

[Carl Schwamberger]

Was looking at specs for a couple French AFV designs in prototype circa 1939 & started wondering what portions of those would have been transferable to US manufactoring methods and doctrine in 1940-41. That is had a French tank corps team brought theirs specs to the US in 1939 what items would it be practical to either manufactor for the French, and adopt into US tank prototypes.

[OpanaPointer]

Were the French designs superior to what we produced? If so would the new tanks have changed our strategy and tactics?

[Carl Schwamberger]

In 1939? Yes. The M2 Medium & M1 or 2 light tank were mechanically equal to the comparable French tanks, but the riveted and welded armor was inferior in construction and design to the welded & cast steel used on contemporary French designs. The French 45mm tank gun in production in 1939 was superior to the US 37mm tank gun. The M3 that was a interm design came into production in 1941 & was inferior to French 1939 prototypes like the G series or G1 that had emerged between 1935 & 1939. The US M4 medium tank that was designed & went into production 1941-42 was roughly comparable to the G series prototype in testing in 1940. the G1 prototype had a better armor & engine/drive train layout, the M4 had a better crew allocation. Both were equipped with a medium velocity 75mm cannon. Since the G1 was not tested to completion its difficult to compare other details. But, in 1939 the best the US could produce was the M2 & what became the M4 was only a collection of 'wish list' specifications, conversely French tanks in production like the S35 or R40 were both far superior to the M2 Medium in armor, & firepower while the G1 prototype was well along.

This site: http://www.chars-francais.net/2015/inde ... 930-a-1940

is a fairly good overview of the French tanks in production & in development in 1939. Again, I'm wondering what of that technology would have been practical to transfer to the US?

[Richard Anderson]

In 1939? Yes. The M2 Medium & M1 or 2 light tank were mechanically equal to the comparable French tanks, but the riveted and welded armor was inferior in construction and design to the welded & cast steel used on contemporary French designs.

Not really. From my Ms. While riveted construction was obsolete, US Army Ordnance moved away from it quickly. Welding was certainly as good in technique as the French, while in terms of casting: "In September, the General Steel Company of Chester, Pennsylvania, completed an experimental casting of the proposed Medium Tank M3 upper hull. It was quickly shipped to Aberdeen Proving Ground for ballistic testing. The results demonstrated the steel industry was capable of producing such large castings – at the time it was believed to be the largest armor casting of its complexity to date – that reduced the amount of assembly time, eliminated riveting, and saved about $3,000 per tank. On 19 June 1941, the Ordnance Committee “authorized the use of cast upper hulls for medium tanks”, which would make the production of large numbers of medium tanks for the American arsenal even easier."

The French 45mm tank gun in production in 1939 was superior to the US 37mm tank gun.

Again not really. You are confusing the excellent SA37 47mm AT Gun, which was just going into production in late 1939 and was scarce in May 1940, with the SA34/35 47mm Tank Gun, which were mounted in the Char B1 and Somua S35. The tank gun had a Mv of 2,165 FPS compared to the 2,900 FPS of the 37mm M3 AT Gun and M5/6 Tank Gun.

The M3 that was a interm design came into production in 1941 & was inferior to French 1939 prototypes like the G series or G1 that had emerged between 1935 & 1939. The US M4 medium tank that was designed & went into production 1941-42 was roughly comparable to the G series prototype in testing in 1940.

Sorry, but that is fiction. None of the G1-series prototypes were ever completed. All that "emerged" of the G1-series from 1935 to 1939 was the utter inability of the French Army Ordnance and French industry to agree to anything regarding the G1 requirements, let alone produce a prototype. The five design proposals, Lorraine's G1L, Renault's G1R, Baudet Donon Rousel's G1B, Fouga's G1F, and SEAM's G1P all went exactly nowhere, while SOMUA's and FCM's proposals were never even considered. Only the G1P came close to being finished...and it didn't have a turret, since none of the three proposed turret designs was ever completed either.

the G1 prototype had a better armor & engine/drive train layout, the M4 had a better crew allocation. Both were equipped with a medium velocity 75mm cannon. Since the G1 was not tested to completion its difficult to compare other details. But, in 1939 the best the US could produce was the M2 & what became the M4 was only a collection of 'wish list' specifications, conversely French tanks in production like the S35 or R40 were both far superior to the M2 Medium in armor, & firepower while the G1 prototype was well along.

So the French effort expended on the G1-series from its first RFP in May 1936 to the cancellation of the program, which hadn't achieved a complete prototype, in February 1940, is somehow "better" than the American effort to produce the Medium Tank M3? The one which was conceived on 5 June 1940, mocked up (and the design finalized) on 26 August, pilot completed on 13 March 1941, and large scale production was in place by the end of September 1941. So the French taking four years to do zilch is something to envy over getting a tank in quantity in 1 year, 3 months, and 25 days?

Seriously?

is a fairly good overview of the French tanks in production & in development in 1939. Again, I'm wondering what of that technology would have been practical to transfer to the US?

Likely none.

[Mil-tech Bard]

Carl,

Regards this --

In 1939? Yes. The M2 Medium & M1 or 2 light tank were mechanically equal to the comparable French tanks, but the riveted and welded armor was inferior in construction and design to the welded & cast steel used on contemporary French designs. The French 45mm tank gun in production in 1939 was superior to the US 37mm tank gun. The M3 that was a interm design came into production in 1941 & was inferior to French 1939 prototypes like the G series or G1 that had emerged between 1935 & 1939. The US M4 medium tank that was designed & went into production 1941-42 was roughly comparable to the G series prototype in testing in 1940. the G1 prototype had a better armor & engine/drive train layout, the M4 had a better crew allocation. Both were equipped with a medium velocity 75mm cannon. Since the G1 was not tested to completion its difficult to compare other details. But, in 1939 the best the US could produce was the M2 & what became the M4 was only a collection of 'wish list' specifications, conversely French tanks in production like the S35 or R40 were both far superior to the M2 Medium in armor, & firepower while the G1 prototype was well along.

This site: http://www.chars-francais.net/2015/inde ... 930-a-1940

is a fairly good overview of the French tanks in production & in development in 1939. Again, I'm wondering what of that technology would have been practical to transfer to the US?

The French adherence top one-man turrets vice the two man Anglo-American and three man German turrets fatally compromised French tanks as fighting vehicles.

French tanks were -- at best -- a form of assault gun due to the fact that French tank commanders were so task over loaded. And the French radios were inferior to Anglo-American tanks, when they had them at all.

The early riveted M3 Stuarts were far better fighting vehicles, with better radios and larger turrets, than any French tank with a cast one-man turret.

[Carl Schwamberger]

I always appreciate Rich, he keeps me honest.

In 1939? Yes. The M2 Medium & M1 or 2 light tank were mechanically equal to the comparable French tanks, but the riveted and welded armor was inferior in construction and design to the welded & cast steel used on contemporary French designs.

Not really. From my Ms. While riveted construction was obsolete, US Army Ordnance moved away from it quickly. Welding was certainly as good in technique as the French, while in terms of casting: "In September, the General Steel Company of Chester, Pennsylvania, completed an experimental casting of the proposed Medium Tank M3 upper hull. It was quickly shipped to Aberdeen Proving Ground for ballistic testing. The results demonstrated the steel industry was capable of producing such large castings – at the time it was believed to be the largest armor casting of its complexity to date – that reduced the amount of assembly time, eliminated riveting, and saved about $3,000 per tank. On 19 June 1941, the Ordnance Committee “authorized the use of cast upper hulls for medium tanks”, which would make the production of large numbers of medium tanks for the American arsenal even easier."

You got me there. I mis remembered the emergence of the M3 by over 18 months. However the September 1939 date for the first M3 casting is after the French had large cast tank components in routine production for several years. Also we need to keep in mind I was refering to 1939, not 1040 or 1941.

The French 45mm tank gun in production in 1939 was superior to the US 37mm tank gun.

Again not really. You are confusing the excellent SA37 47mm AT Gun, which was just going into production in late 1939 and was scarce in May 1940, with the SA34/35 47mm Tank Gun, which were mounted in the Char B1 and Somua S35. The tank gun had a Mv of 2,165 FPS compared to the 2,900 FPS of the 37mm M3 AT Gun and M5/6 Tank Gun.

Mv is only part of the equation, another important part is the mass of the projectile. Of the weightiest US 37mm combat AP projectiles the M74 & M51 mass at .87kg. For the SA34/35 47mm mass of the AP is given as 1.67 kg. I'm sure you know the formula for finding the energy of the projectile as well as I do. I'm coming up with the 37mm projectile having about 76% of the energy of the 47mm projectile at the muzzle. There are a number of other factors that favor the larger diameter & mass projectile over the smaller. There are a number of sources for penetration of the projectiles. At the shorter ranges, under 300 meters the US gun seems to have 70 to 80% of the penetration of the Fr weapon vs face hardened armor.

The M3 that was a interm design came into production in 1941 & was inferior to French 1939 prototypes like the G series or G1 that had emerged between 1935 & 1939. The US M4 medium tank that was designed & went into production 1941-42 was roughly comparable to the G series prototype in testing in 1940.

Sorry, but that is fiction. None of the G1-series prototypes were ever completed. All that "emerged" of the G1-series from 1935 to 1939 was the utter inability of the French Army Ordnance and French industry to agree to anything regarding the G1 requirements, let alone produce a prototype. The five design proposals, Lorraine's G1L, Renault's G1R, Baudet Donon Rousel's G1B, Fouga's G1F, and SEAM's G1P all went exactly nowhere, while SOMUA's and FCM's proposals were never even considered. Only the G1P came close to being finished...and it didn't have a turret, since none of the three proposed turret designs was ever completed either.

Dont be sorry, Which in 1939 is better than anything the US had. No matter how you cut it the M3 was a inferior concept to the G specification at the start and as it evolved.

the G1 prototype had a better armor & engine/drive train layout, the M4 had a better crew allocation. Both were equipped with a medium velocity 75mm cannon. Since the G1 was not tested to completion its difficult to compare other details. But, in 1939 the best the US could produce was the M2 & what became the M4 was only a collection of 'wish list' specifications, conversely French tanks in production like the S35 or R40 were both far superior to the M2 Medium in armor, & firepower while the G1 prototype was well along.

So the French effort expended on the G1-series from its first RFP in May 1936 to the cancellation of the program, which hadn't achieved a complete prototype, in February 1940, is somehow "better" than the American effort to produce the Medium Tank M3? The one which was conceived on 5 June 1940, mocked up (and the design finalized) on 26 August, pilot completed on 13 March 1941, and large scale production was in place by the end of September 1941. So the French taking four years to do zilch is something to envy over getting a tank in quantity in 1 year, 3 months, and 25 days?

Seriously?

Yeah seriously. I was and am not proposing French automotive development administration was superior. Not sure how you saw that in my statements. They still had a better concept than the M3, earlier, and developed further along in 1939. Neither does any of that negate the existing S35 or H40 being better to the M2 in 1939.

is a fairly good overview of the French tanks in production & in development in 1939. Again, I'm wondering what of that technology would have been practical to transfer to the US?

Likely none.

Likely the managers would have overlooked advantages hypothetical or real. Not invented here often stands in the way. I've searched around a bit for any transferes resulting from all the aircraft the French ordered from the US. While they directed a lot of modifications to the M167 & DB7 for French use its not clear what any US design engineers took from that. The US did adopt some British items like the 6lbr AT gun, or modifiy the 4.7" cannon to fire 4.5" Brit made ammunition, and adapt the Merlin engine, and adapt a number of Brit ship and boat designs for production in the US, and the proximity fuze, and the V1 design from Germany... I could go on with a very long list but wi/out knowing the details of French tank engineering vs US I can only ask the question.