WI: Germany abandons plans for large scale U-boat construction in 1939?

The aim of the WW-II commerce war was to cut the life line to America, not starve the Brits. The main aim was military . I gather the allied WW-II ASW effort cost them ten times what the U-Boat war cost the KM.

Further the tonnage of munitions needed to mount the D-Day operation would still have taken until 1943 to transport and accumulate that much across the Atlantic. This presumes the other operations prior to D-Day [ N.AFRICA & ITALY] are still needed. If not it might be 42/43 , but that had nothing to do with KM.

If the KM had invested in Type IX U-Boats at the expense of warship construction during most of the war - they would have accumulated > 1000 boats boat's by VE-Day each allowing ~8 weeks per sortie, compared to 6 weeks for the Type VII U-Boats. Its not a game changer , but all other things being equal it should have delay D-Day - V-E Day , by 6 -12 months .
 
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I gather the allied WW-II ASW effort cost them ten times what the U-Boat war cost the KM.

The Allied economy was much bigger than the German so even if it was a 10 to 1 cost ratio its still comparitively cheap. All those reinforced concrete sub bases cant have come cheap.
 
[QUOTE="J
But the most important thing is, that U-boat construction effort required a massive amount of raw materials, steel, industrial effort and quality manpower. What would Germans be able to do with all the men and material wasted on Type VII's?[/QUOTE]

Just looking at the amount of steel that should be available for other things;
  • A type VII was about 757 long tons displacement, so figuring 70% of that weight is available steel, that figures to be about 600 tons of steel per boat
  • A quick count of VIIb's and c's laid down shows about 600 total (That might be high for this discussion but oh well)
  • The available steel by not producing these boats is about 360,000 tons of steel
  • Using 24 tons per tank says 15,000 more tanks could have been produced
This is not reflective of the factory capacities but I thought it would be interesting to add to the OP's discussion! I think the OP would like to know if the German Army had 15,000 more tanks would that have made a difference more of a difference in the war then the 600 type VII's.
 
The Allied economy was much bigger than the German so even if it was a 10 to 1 cost ratio its still comparitively cheap. All those reinforced concrete sub bases cant have come cheap.

Well RN was effectively 20% of the UK war effort, while KM was more like 10%, so it made a very real difference to the WALLIES. If the WALLIE industry really was 3 times the AXIS industry and the WALLIE navy was [relatively] 1/5 of that industry , while the AXIS navy was 1/10th their industry- then the WALLIES are investing 6 times as much into Naval war.

Concrete is a poor comparison since it was relatively cheap resource and labour.
 
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[QUOTE="Tonrich ]
But the most important thing is, that U-boat construction effort required a massive amount of raw materials, steel, industrial effort and quality manpower. What would Germans be able to do with all the men and material wasted on Type VII's?
Just looking at the amount of steel that should be available for other things;
  • A type VII was about 757 long tons displacement, so figuring 70% of that weight is available steel, that figures to be about 600 tons of steel per boat
  • A quick count of VIIb's and c's laid down shows about 600 total (That might be high for this discussion but oh well)
  • The available steel by not producing these boats is about 360,000 tons of steel
  • Using 24 tons per tank says 15,000 more tanks could have been produced
This is not reflective of the factory capacities but I thought it would be interesting to add to the OP's discussion! I think the OP would like to know if the German Army had 15,000 more tanks would that have made a difference more of a difference in the war then the 600 type VII's.

They had ~ 1000 U-Boats built during the war- so the figure should be well over 3/4 million tons steel. However the raw resources involved must be massive because the monthly allocation of steel to navy in 1944 was 58,000 tons 'warships' and 16,000tons MV. If we assume 'warship' = U-Boat while MV = others [T-BOOT/M-BOOT/S-BOOT/MFP/AFP etc],...then the 1944 U-Boat production required ~ 700,000 tons to build couple hundred U-Boats? That's an average of ~3000tons per U-Boat. Tanks we similar with roughly 1.2 million tons for the 1944 production of roughly 19,600 AFV or 63 tons per tank. In earlier years the figure is 43-41 tons per tank suggesting the figure is double actual tank mass to a first approximation. But that means the figure covers ALL steel requirement's for the ENTIRE tank industry factory quarters bomb damage repairs etc etc.

Maybe the difference between 1944 and earlier years has as much to do with damage repairs?

But AT BEST that is only going to cover part of the mass that went into a tank as a product. Roughly 1/2 the tonnage of tank is armor and the other half is the engine / transmission and suspension ,gun ,ammo etc. That all is labour/tech intensive and therefor can't just be hand waved into existence. To harvest that much is going to have to come from somewhere.

Where else would you 'steal' from?

How would you make that work.
 
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How does the amount of machining for a marine diesel compare to a tank engine? I’m assuming the difference in scale would require different tooling, which is a whole different problem again.
 
How many trucks can be built for say, 10 tanks? Early in the war I think it would be better to use that additional steel to favor trucks and half tracks over tanks.

And thinking of steel savings, how much steel is Britain saving through fewer ships sunk, fewer new construction of merchant men and escorts?
 
I'd be more interested in how much more railway and automotive transport might be had absent these submarines, or surface ships. Does a early decision mean that in 1940 45% of the German artillery is motorized/mechanized, vs 20% of OTL? Does it mean the Soviet railways are restored 300% faster in 1941?
 
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And thinking of steel savings, how much steel is Britain saving through fewer ships sunk, fewer new construction of merchant men and escorts?

Obtain a copy of John Ellis 'Brute Force' There are a number of charts/graphs/tables for the battle of the Atlantic losses that you can extrapolate the answer from.
 
Germany started the war with well over 3 million vehicles [1/2 cars if sales = anything] . By the end of the war that figure was only 160,000 vehicles. Though out the war the civilian economy usage of fuel & vehicles fell to 1/2 prewar levels in 1940/41 and down to 1/3 by 1944. These vehicles were commandeered through out the war to help make up shortfalls, perhaps 3/4 million vehicles, but most were lost though out the second half of the war to lack of spare parts and WALLIE bombing.

Why wait for that? If you want more vehicles-why not plunder over a million vehicles from the country from 1939-1941, That should make nearly 100% motorization through this time period.

285k >522k 1939
310k >610k 1940
430k >950k 1941

The civilian economy can make use of over 1 million horses readily available through these years plus the maybe 1/4 million wagons karts and limbers etc.
 
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