If Doenitz had his 300 U-Booats after the Fall of France?

I don't know exactly but i think that 300 submarines would be equal to 2-3 Panzer Divisions(anyone that knows more can say if that is correct?)
So,if he manages to convince Hitler that they need to win the BoB in the water,what would be the effects of such decision?I think that IF they won in Britain the subs can be melted to tanks in 6 months-1 year
 
I don't know exactly but i think that 300 submarines would be equal to 2-3 Panzer Divisions(anyone that knows more can say if that is correct?)

Assuming an average of about 1,000 tons per U-boat, 300 would require a lot more metal etc than 900 tanks. The latter would require under 40,000 tons of steel. The U-boats would require several times that amount.

So,if he manages to convince Hitler that they need to win the BoB in the water,what would be the effects of such decision?I think that IF they won in Britain the subs can be melted to tanks in 6 months-1 year

It would've been better to invest the metal and labor wasted on Bismarck and Tirpitz on more subs. Had 300 been available by July 1940, without sacrificing army or Luftwaffe strength, they might've forced Britain to give up in 6-12 months.
 
I don't know exactly but i think that 300 submarines would be equal to 2-3 Panzer Divisions(anyone that knows more can say if that is correct?)
So,if he manages to convince Hitler that they need to win the BoB in the water,what would be the effects of such decision?I think that IF they won in Britain the subs can be melted to tanks in 6 months-1 year

And why exactly is Germany planning for a war at sea with the British when their main priorities are beating the French and conquering Russia? Especially as basically up until 1939 Hitler has no reason to expect Britain to fight and even admires the British Empire?

For that matter a massive build up of U-Boats that would have to have started several years before the outbreak of war would have been a huge give away of German intentions and the British might have been a lot less accommodating at Munich if they know delaying means facing a massive U-boat force. Not to mention the RN would invest a lot more heavily in ASW in the prewar period faced with this situation.
 
And even if the steel is available things like copper aren't. Not to mention dockyard space and crews. Or fuel...
 
It would've been better to invest the metal and labor wasted on Bismarck and Tirpitz on more subs. Had 300 been available by July 1940, without sacrificing army or Luftwaffe strength, they might've forced Britain to give up in 6-12 months.

Except this doesnt happen in a vacuum. If the Brits see a lack of capital ship construction and a focus on subs, they can cancel/delay their own BBs and focus on escorts.
 
the KM would not need the extreme of "300 u-boats!!" to have been deadly effective. they could have built a force of 100 - 300 tonne u-boats, transportable by rail, in somewhat greater numbers (say approx. 100 in the various displacements)

probably can be somewhat concealed from Allies, the numbers at any rate would probably not provoke much change in RN construction plans?
 
The French navy had a robust submarine fleet. Churchill made a big show of sinking French battleships, but the French submarines had been obtained by Doenitz it would have been a serious threat.
 
Since the U-boat threat was not the top priority in the early years of the OTL war, the Brits failed to do what they COULD have done. Like: Focus not just on escorts but on the Fleet Air Arm and the development of planes with longer range to cover the entire northern Atlantic. Also get much tougher with Ireland about the needed naval bases than was prudent in OTL. Also put massively greater resources into developing U-boat detection devices. Also cut back on the massive production of bombers that don't hit anything much over Europe (fire Bomber Harris). Continued use of bombers should focus on sowing anti-sub mines (newly developed ones better than those OTL) wherever the sub bases are. Also, possibly, seize one of Portugal's Azores islands as a base for sub-hunting (this may not be necessary if all the above is done). More emphasis on finding new techniques for intensive domestic (and Irish) agricultural production--surely there is more that could be done than was ever done in OTL.

Finally, 300 U-boats on the prowl means more potential for deadly clashes with the U.S., which might bring it into the war earlier.
 

Deleted member 1487

Finally, 300 U-boats on the prowl means more potential for deadly clashes with the U.S., which might bring it into the war earlier.
Not really if they stay outside the US zone. The clashes came when the Uboats and USN strayed into the grey line between the end of the war zone and the US protection zone in 1941 after British convoy defenses had gotten so effective that Uboats had to push out further East toward America to avoid things like land based air power and hunter-killer groups. Things that didn't really exist in strength until the second half of 1941.
 

Rubicon

Banned
300 U-boats in summer of -40? That would close down the Atlantic, hard. There were what 15-20 U-boats at sea at any one time at most? 300 U-boats would at least quintuple that figure (1/3 at sea, 1/3 moving to or from their patrol zone and 1/3 in port). The convoy losses would be massive.

Problem no.1 has already been mentioned, how to phyisically get to that number. Germany would have to very likely not build anything larger then a light cruiser for them to reach that amount.

Problem no.2 politically Germany was limited in the Anglo-German naval treaty to 50% of the British submarine tonnage, which could be expanded to 100% in an emergency. Great Britain had about 100K tonnage of submarines. Going above either of these limits will very warn the British much earlier that Germany doesen't care about any treaties.
 
I don't know exactly but i think that 300 submarines would be equal to 2-3 Panzer Divisions(anyone that knows more can say if that is correct?)
So,if he manages to convince Hitler that they need to win the BoB in the water,what would be the effects of such decision?I think that IF they won in Britain the subs can be melted to tanks in 6 months-1 year

Given the devastation caused by a relative handful of U Boats had 300 been available which triples or Quadruples the number of boats at sea at any given time over OTL - and this will suddenly massively up the number of ships being sunk beyond a sustainable number month on month which means that the British have to react and react fast.

The quickest thing the Brits can do is retask Bomber command to coastal command (which is what they should have done OTL) given the impact a relative handful of aircraft had on the BOA suddenly having scores if not hundreds operating across the western approaches and as far as possible covering convoys is goign to cause the Uboat fleet many problems.

While it would not be the Sailing to their deaths of May 43+ as many of the technologies necessary for that victory still had to align for the Allies - it would still result in many U-boat losses and

Historically the losses in 1940-43 while heavy proved too be low enough for the combined voices of bomber commands Linderman, Harris and Portal to drown out any attempt to wrest suitable aircraft away from the Strategic bombing of Germany.

For example between 1941 and early 1943 the RAF only had one Squadron of VLR Liberators tasked to Coastal command - a squadron that had to scrounge for spares from BC and many of the 'few' bombers assigned earlier in the war were 2nd class bombers.

If the Germans can keep 4x as many Uboats at sea over OTL those voices will no longer be loud enough and the resources of BC will be transferred to Coastal Command

Then of course curtail any large warship construction and concentrate on building as many escorts as possible and training crews accordingly.

Also I do not believe that the Germans building 300 U Boats by 1940 is achievable - recall that they had only started making them again in 1936

Secondly if Germany is not making Panzer divisions then it might not beat France in 1940 making the whole BOA Academic anyway.

Germany had IIRC 9 Pz Divisions involved in the Battle of France - and they were a critical component in the success of that battle - start removing several of these Pz Divisions and well - maybe France can hold on?

Also the majority of Steel used by Germany in WW2 was overwhelmingly in the construction of buildings and fortifications - not in the building of tanks and warships etc.

What prevented Germany from having built several times more tanks, Aircraft and U-boats etc was the same restriction as everyone else - the lack of factories / trained workers.

Building armament industries takes years of planning and investment - German tank production for example reached its highest output in 1944 despite the attentions of Bomber command and the USAAF - this is because many sites of the German war industry vital for the construction of tank components etc were still expanding between 1939 and 1943

So it is impossible for a large part of the Armaments industry to switch from Tank production to U-boat construction and then back to Tank production in the space of a few years.

Germany cannot win on land without a massive investment in Tank/AFV production and cannot possibly 'Win' the war without a large number of U-boats.
 
Those 300 U-boats need 300 skippers and 300 executive officers and 300 engineering officers, all of whom need to have a reasonable level of experience. They also need a compliment of senior chief petty officers/petty officers with experience and technical expertise. A reasonable proportion of these crews need to have some experience they can't all be pollywogs. Germany had no submarines until 1935 and the Anglo-German agreement with the exception if a few small training submarines built outside Germany 1933-35. Obviously there were former U-boat officers and crewmen from WWI still living in Germany and in physical condition to serve at least as training cadres - how many would step up to do this is debatable. To have the 300 (ocean going) U-boat force, even if you overcome the reality that Germany could not build that many on top of a certain number of coastal and training submarines needed. The crew of an ocean going U-boat was 45-50 officers and men, subtracting the 3 very experienced officers and the experienced senior petty officers this means 12,000 men to staff these boats from junior officers with some experience to seamen trained but on their first cruise. Add in those on training duty and other non-seagoing duties but who are submarine trained qualified this means perhaps 20,000 U-boat qualified officers and men in the force by 1940.

Starting from essentially zero in 1933 - no submarines, no shore establishment, and a minimal base of trained/qualified personnel getting the personnel to man and sustain a force of 300 ocean going submarines plus the training and shore establishment is simply not doable. Plan Z planned for 279 submarines, and that was by 1946.
 
The French navy had a robust submarine fleet. Churchill made a big show of sinking French battleships, but the French submarines had been obtained by Doenitz it would have been a serious threat.

Training crews and restarting support functions for those subs would take time. Theres been some threads on this specific question. Judging from the time it took the Germans to generate qualified crews for their submarines, and adding in time for additional preparation on new mechanical systems, it would take about a year to get anything effective out of the French sub fleet. Toss out obsolete & unsuitable models and you can have maybe half or less of the French sub fleet operational after July 1941.
 
Germany cannot win on land without a massive investment in Tank/AFV production and cannot possibly 'Win' the war without a large number of U-boats.

Precisely the dichotomy that these sorts of threads usually try to dance around. What Nazi Germany wanted and needed were quick victories, they made no plans for anything else.
 

thorr97

Banned
Garrison,

What Nazi Germany wanted and needed were quick victories, they made no plans for anything else.

It's not that "they made no plans for anything else" so much as they could not afford to do anything else. The Germany economy was too small, its resource access was too limited, and it could not afford to wait and remedy that while its opponents - all with much larger economies, better resource access, and much greater population numbers - were rearming at a furious pace.

It was a question of striking sooner and getting lucky or waiting until they were truly ready and definitely losing.
 

Redbeard

Banned
Building that many U boats will require huge resources and lengthy preparation. The Anglo-German naval agreement will not be old before the British realise Germany is going to be a serious threat to British interests (not just continental). No Anschluss and no Munich but France will be supported in having a go at Germany at first opportunity.

BTW from a quick search a Type VII U.Boat would cost as much as 50 tanks, so 300 U boats will make the Wehrmacht short of 15.000 tanks. They had 3000 in 1940...
 
Training crews and restarting support functions for those subs would take time...

And not everyone is fit for sub duty. I served on a surface ship and was constantly seasick. Just visiting the sub in Philadelphia moored next to OLYMPIA I got a bit claustrophobic despite the fact the sub was practically empty and there were only four people on board (I was one). So getting crews is NOT going to be easy...
 
Those 300 U-boats need 300 skippers and 300 executive officers and 300 engineering officers, all of whom need to have a reasonable level of experience. They also need a compliment of senior chief petty officers/petty officers with experience and technical expertise. A reasonable proportion of these crews need to have some experience they can't all be pollywogs. Germany had no submarines until 1935 and the Anglo-German agreement with the exception if a few small training submarines built outside Germany 1933-35. Obviously there were former U-boat officers and crewmen from WWI still living in Germany and in physical condition to serve at least as training cadres - how many would step up to do this is debatable. To have the 300 (ocean going) U-boat force, even if you overcome the reality that Germany could not build that many on top of a certain number of coastal and training submarines needed. The crew of an ocean going U-boat was 45-50 officers and men, subtracting the 3 very experienced officers and the experienced senior petty officers this means 12,000 men to staff these boats from junior officers with some experience to seamen trained but on their first cruise. Add in those on training duty and other non-seagoing duties but who are submarine trained qualified this means perhaps 20,000 U-boat qualified officers and men in the force by 1940.

Starting from essentially zero in 1933 - no submarines, no shore establishment, and a minimal base of trained/qualified personnel getting the personnel to man and sustain a force of 300 ocean going submarines plus the training and shore establishment is simply not doable. Plan Z planned for 279 submarines, and that was by 1946.

This is the other good point - while Germany did have very few subs operational at the Start of the war - the quality and dare I say courage of the Crews of these relatively handful of boats was very high and they willing to perform very dangerous attacks (indeed this was to cost many their lives as the Allies ASW skills and technologies improved) - this was diluted as experienced crews were killed off / spread across the fleet - the skills of the U-boat captains and crews of later boats was not as high - particularly in the face of mounting casualties.
 
And why exactly is Germany planning for a war at sea with the British when their main priorities are beating the French and conquering Russia? Especially as basically up until 1939 Hitler has no reason to expect Britain to fight and even admires the British Empire?

But Germany was building large warships like Bismarck, presumably to help counter the RN.

For that matter a massive build up of U-Boats that would have to have started several years before the outbreak of war would have been a huge give away of German intentions and the British might have been a lot less accommodating at Munich if they know delaying means facing a massive U-boat force.

But they already faced the prospect of the Luftwaffe etc and down to early '39 the policy was to avoid through appeasement.

Not to mention the RN would invest a lot more heavily in ASW in the prewar period faced with this situation.

Sure but look at actual history. Tonnage sunk by U-boats peaked in late 1942, when Britain, after the wake up call at Scapa Flow etc, had had three years to increase ASW forces. Most of the sinkings were in peripheral areas but the hypothetical 300 can include plenty of type IXs as well as VIIs and down to 3/'43 the latter, or convoy attacks, were still effective.
 
Building that many U boats will require huge resources and lengthy preparation. The Anglo-German naval agreement will not be old before the British realise Germany is going to be a serious threat to British interests (not just continental). No Anschluss and no Munich but France will be supported in having a go at Germany at first opportunity.

Actual history suggests Chamberlain would've been slow to implement a get tough policy.

BTW from a quick search a Type VII U.Boat would cost as much as 50 tanks, so 300 U boats will make the Wehrmacht short of 15.000 tanks. They had 3000 in 1940...

As I wrote before they could've built many more U-boats had they not built Bismarck, Tirpitz, Scharnhorst, Gneisanau etc. By 1943 they were producing U-boats at a faster rate than before yet this hardly stopped tank production--plenty of Panthers and Tigers were being built.
 
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