How effective were U-boats during WWII?

[Grifter808]

I was browsing through the internet and looking for info on U-boats. What I got from my search was, as much Allied tonnage sunk that were attributed to U-boats, it only represented 1% of Allied shipping where the U-boats operated. Is this true?

I just always thought that the amount of sunk tonnage was more significant than that. Forgive me for not providing a link to the site where I saw this info. from. History buffs, can someone please clarify?

[Tullaian]

Early in the war they were hugely succsessful sinking boats faster than Britain could make them and came close to turning the tide of the war. Churchill rated them the greatest threat to Britain's survival at one point in time. However as the war went on and America joined the war the uboats could no longer keep up with the massive increase in manufacturing availiable to the Allies and the % totals started to fall. By 1943 the ASW technology had the clear upper hand and tonnage totals started to fall dramatically.

In late 1942 the uboats were sinking in the order of 700,000+ tonnes of allied shipping a month , by the end of 1943 that had died to a trickle.

[Duli]

I was browsing through the internet and looking for info on U-boats. What I got from my search was, as much Allied tonnage sunk that were attributed to U-boats, it only represented 1% of Allied shipping where the U-boats operated. Is this true?

I just always thought that the amount of sunk tonnage was more significant than that. Forgive me for not providing a link to the site where I saw this info. from. History buffs, can someone please clarify?

I think that this 1% thing is wrong.

[Grifter808]

I was browsing through the internet and looking for info on U-boats. What I got from my search was, as much Allied tonnage sunk that were attributed to U-boats, it only represented 1% of Allied shipping where the U-boats operated. Is this true?

I just always thought that the amount of sunk tonnage was more significant than that. Forgive me for not providing a link to the site where I saw this info. from. History buffs, can someone please clarify?

I think that this 1% thing is wrong.

I think so too.

[Laffertytig]

1941 was the darkest year for britain. when germany foolishly declared war on USA in dec41 that was the end. germany couldnt hope to compete with the industrial sizes of USA, UK and russia. in uboat terms there were just far to many ships being built and not enough uboats to sink them

[Curval]

Someone posted an article about Prien and it gives a detailed account of the U-Boat history in WW2.

Great article.

Found it:

http://www.u47.org/english/u47_kri.asp

[blueparrott]

In Clay Blair's "Hitler's U-boat war - The hunted 1942-1945" the there is a statistic mentioned. It deals with the period Sept -42 till May -45 and so does not include either of the so called "happy times", but still.

He claims that during this period 953 convoys comprising 43 526 ships sailed on the North and Mid Atlantic runs. 272 of these were sunk!! by u-boats (that is 0.6%)

He further claims that during the entire war there was 2919 ships sunk by u-boats. I havent been able to find any figure of total sailings, single or in convoy but the 1% sunk does not seem that unrealistic.

I know numbers cannot tell the entire story, but I still think the numbers are interesting and thought provoking.

[Nopileo]

Those of you who don't use SH3 Commander should give it a try. The information screen for each month throughout the war gives the stats of how much tonnage sunk versus how many subs lost.

For example, early war gives stats like '300,000 tons of shipping sunk for 2 u-boats lost', while later on it's more like '50,000 tons of shipping sunk for 25 u-boats lost'. It gives you an idea of what you can expect for the coming patrol...

[Shadow9216]

I highly recommend Blair's two-volume work. It's very detailed, and includes references from other, often-cited works, including German records, British and American archives, etc. It shows month by month, convoy by convoy, what the losses were. I'm not going to get into the details, as the book does a much better job of that.

More importantly, he goes into the mentality which prevailed at the time, and offers explanations for why things have been distorted, either minimizing or maximizing the actual impact.

The conclusions are surprising, but the facts are there, along with the original sources should anyone wish to examine the original documents.

The books in no way diminish the cost of the war, nor diminish the efforts on both sides. In some ways, a more objective look puts their efforts into perspective, and reveals a whole new respect for the crews of both sides.

[pampanito]

I completely agree. Blair's book is not taking anything for granted from previous secondary sources, and he just digs out the basic facts and figures.
Some of his conclusions had been suggested before by some authors, and dismissed by the 'official' historians. For example, any comment that Doenitz was perhaps not always correct in his decisions and grasp of situations is regarded by many as anathema. But probably Doenitz was tragically wrong when he viewed the submarine war as an attrition campaign, where the only important thing was to sink merchantmen, regardless of cargo, flag or destination. This Tonnage tactic was tantamount to declare war on the entire World merchant fleet and shipbuilding capacity (excluding of course Japan and Italy), a war that could simply not be won with the available U-boat force.
To send big type IXs to the South Atlantic or the Indian Ocean, in patrols taking up to three months, returning with just a couple of ships sunk, can only be viewed as a waste. To risk heavy losses while attacking westward-going convoys with mostly ships in ballast, was still worse. Churchill and other Allied leaders expressed only relief when U-boats were scoring considerable success off Freetown, off the Brazilian coast, on the Mozambique Channel, on the Arctic. To them, the only important theather was the North Atlantic and the life-line coming from America; the only thing that certainly made them shudder was that that lifeline would be cut, even if for a short time. For Germany it was a tragedy that whole U.S. armies and Air divisions were deployed to the UK almost without interference from U-boats in 1942/44. I hate to say this, but in this case Hitler was right in his strategic view of the U-boat war, he many times disagreed with Doenitz on the 'remote theathers' policy and was stubborn that all front-line boats should be deployed in the North Atlantic and only against traffic coming from the US (although he also gave in to the pressures from Italy and Rommel, and allowed many U-boats to be squandered in the Mediterranean).

Please excuse me for this long exposition, when I start I just can't stop! :oops: I'm possibly wrong in such a whole-hearted support of Clay Blair's ideas, but they are coincident with my own. I never understood what influence in the German war effort had the sinking of a ship carrying oranges from Southern Spain to Argentina, as was the real case.

[Gunfighter34]

You might also find the information in this paper interesting:

http://www.chinfo.navy.mil/navpalib/ships/submarines/centennial/wwii-campaigns.html

[Abraham]

I've once found some info, I don't know the source anymore, stating that one third of the U-boats never intercepted a convoy at all!
Since I have to rely on my memorie I'am not 100% sure (about 90%!), but Der Teddy Bär should know...

[Sarge McSarge]

It all depends on how you look at the stats.


In Clay Blair's "Hitler's U-boat war - The hunted 1942-1945" the there is a statistic mentioned. It deals with the period Sept -42 till May -45 and so does not include either of the so called "happy times", but still.

He claims that during this period 953 convoys comprising 43 526 ships sailed on the North and Mid Atlantic runs. 272 of these were sunk!! by u-boats (that is 0.6%)

He further claims that during the entire war there was 2919 ships sunk by u-boats. I havent been able to find any figure of total sailings, single or in convoy but the 1% sunk does not seem that unrealistic.


There was not 43,526 ships but 43,526 individual voyages. Was this 45 ships each doing every one of 953 convoys or 90 ships doing 476 convoys?? 272 does not look so bad when you look at it this way. If the sinking percentage was 1% per voyage then 10 voyages puts your odds up to 10%

A better way of looking at it is to look at the percentage of capacity sunk.
The total allied merchant shipping tonnage available in the Atlantic and Med was about 67 million tons. This includes about 38 million tons constructed during the war as well as what existed at the start. The U boats sunk about 14.5 million tons so it is closer to 25% of total and about half of what was available at the start of the war.

Sarge

[blueparrott]

[/quote]

There was not 43,526 ships but 43,526 individual voyages. Was this 45 ships each doing every one of 953 convoys or 90 ships doing 476 convoys?? 272 does not look so bad when you look at it this way. If the sinking percentage was 1% per voyage then 10 voyages puts your odds up to 10%

A better way of looking at it is to look at the percentage of capacity sunk.
The total allied merchant shipping tonnage available in the Atlantic and Med was about 67 million tons. This includes about 38 million tons constructed during the war as well as what existed at the start. The U boats sunk about 14.5 million tons so it is closer to 25% of total and about half of what was available at the start of the war.

Sarge[/quote]

Very good point (even though I am loath to admit it! :-))
Tonnage is an important aspect, especially if you consider it in a time frame. Tonnage lost in 1939 is unavailable for the entire war whereas tonnage lost in 1945. The figures of new construction also points to tonnage lost early in the war had a greater impact on total available tonnage than in the later years.
...and you can compare that with available u-boats to get a better grasp of effectiveness. All in all a complicated picture but very interesting.

I don't agree, though, that sinking westbound ship in ballast was a complete waste. Yes, it is more efficient to sink ship AND gargo, but a ship sunk is one less ship to carry cargo next time.

[Abraham]

But remember that the cargo is often more expensive than the carrier (the ship)!

To complicate things further you have to look at the resources used to maintain the sub campaign from the German side and the resources needed from the Allied side to beat it.

I think the U-boat campaign was from a material (not human!) point of view a cost-effective way of waging war and the only means that could perhaps have brought Britain on its knees, if there had been a concentrated effort from the German side.
But the Germans never had proper support from the Luftwaffe, neither with long range patrols over the Atlantic with Condors nor with air defence above the Bay of Bisqai...

The Battle of the Atlantic was won in the air, by the Allies.

[P_Funk]

Really if you want to learn about the U-Boat war you can't read one book or look at one site. Every book is different and has different information along with a different take on it as well as a particular bias. I've read 3 different book which covers the war in the Atlantic and each was different and each had different informative value. The only way to learn is to read.

As Winston Churchill said: "Read History! Read History!"

I started with Lothar Gunther Buchheim's "U-Boat War" and followedit up with "The Battle of the Atlantic" by Andrew Williams. Both are quite good books which cover the war. Buchheim's covers the personal side of what it's like to live in a sub and the latter is more of an overview which gives insight into the goings on on both sides of the war and all the action in the middle. I recommend both.

[clive bradbury]

Absolutely - read history! Careful how you read it, though, especially with Blair. Good books in parts but he has a strong anti-British agenda throughout - partly due to lack of understanding of the British mindset as he views everything from an American perspective.

[Pablo]

It all depends on how you look at the stats.


In Clay Blair's "Hitler's U-boat war - The hunted 1942-1945" the there is a statistic mentioned. It deals with the period Sept -42 till May -45 and so does not include either of the so called "happy times", but still.

He claims that during this period 953 convoys comprising 43 526 ships sailed on the North and Mid Atlantic runs. 272 of these were sunk!! by u-boats (that is 0.6%)

He further claims that during the entire war there was 2919 ships sunk by u-boats. I havent been able to find any figure of total sailings, single or in convoy but the 1% sunk does not seem that unrealistic.


There was not 43,526 ships but 43,526 individual voyages. Was this 45 ships each doing every one of 953 convoys or 90 ships doing 476 convoys?? 272 does not look so bad when you look at it this way. If the sinking percentage was 1% per voyage then 10 voyages puts your odds up to 10%

A better way of looking at it is to look at the percentage of capacity sunk.
The total allied merchant shipping tonnage available in the Atlantic and Med was about 67 million tons. This includes about 38 million tons constructed during the war as well as what existed at the start. The U boats sunk about 14.5 million tons so it is closer to 25% of total and about half of what was available at the start of the war.




Sarge
The 272 ships lost out of 43,526 tries is pretty good - for the Allies. For example, it means you had a better chance (overall) of crossing the Atlantic in the face of the U-boat peril from Sept. '42 through May '45 than you would have surviving a flight on the Space Shuttle tomorrow.

From a practical standpoint, it meant the Allies had enough transport capacity (however much they lost of their pre-war capacity) to get enough troops and supplies to England to feed, clothe, and house the local population, support an extensive bombing campaign, significant naval operations, and support offensive ground operations in Italy and Western Europe.

I would have to say that the Battle of the North Atlantic was primarily won by the Allies when they won the intelligence war, since it allowed them to figure out where the U-boats were and move convoys around them while moving hunter-killer groups and aircraft to them. They didn't win the war by sinking U-boats (although that helped) - they won by neutralizing them. If the convoy gets through unscathed, the U-boat has been neutralized - whether because the convoy dodged around them, the destroyers or patrol aircraft knew where the u-boat were and so forced them to dive so they couldn't get into firing position. Either way, the Allies win.

Pablo

[XXi]

I remember A book concerning the Battle of Atlantic that mentioned one of the reasons Doenitz simply couldn`t win - in 1942 there were quite many months when U Boats were sinking 700,000 BRT or more. Meanwhile, though, American shipyards were able to lay down up to 1,500,000 BRT monthly. As a result, in late 1943 all merchant loses since the beginning of the war were actually replaced by brand new, large vessels.

Not to forget what all other people here said, of course. The tonnage wasn`t the only factor.

Sometimes I wonder, how Doenitz could think that it is possible to sink the tonnage with the means that were available ? Cutting off the North Atlantic vein could be much more effective.
I presume - but so far it`s just my point of wiev - that perhaps he saw it from WW I perspective, when Germany almoust won the war against Britain due to massive tonnage loses and the American presence in te Atlantic was not that important. So, he though rather about the same way of winning the war, the way that couldn`t work 20 years later.

[Shadow9216]

Funny thing about the great failures of history- the "what if's?" - is that no one ever considers the winning side. What if Britain had adapted its tactics earlier? What if Coastal Command received most of the Liberators rather than Bomber Command? What if The night surface tactics of WWI had been studied more carefully by the Royal Navy- or even Doenitz's book, describing his theories, which was available prewar?

Sure, if Germany had done several things different, they may have reached their goal...but perhaps that would have forced a dramatic rethinking of British strategy. Maybe they would have reacted differently...maybe the US would've intervened, instead of waiting. Who knows?

[Gunfighter34]

I think the German strategy could have worked, but they had a short window of opportunity to get the job done, which lasted maybe through early 1942. They simply didn't have enough boats at the start of the war to make a knockout blow, and it's remarkable that they did as well as they did.

To be fair to the Germans, while everyone knew that America's industrial might was massive, I don't think anyone (including us) foresaw just how incredible a force we would be. One Liberty ship, the Robert E. Peary, was completed in about five days, and we built over 2,500 Liberty-class transports alone! We produced over 80,000 Sherman tank chassis. We turned out staggering numbers of P38s, P40s, P47s, P51s, etc.

So really, the Germans were fighting a losing battle. Had they not invaded Russia in '41 they might have stood a better chance, but they spread themselves too thin and then had to add to their troubles an America whose productivity was increasing on average 40% a year from 1942-45.

[blueparrott]

I think the point of the discussion of alternate tactics is always for the losing side and very seldom for the winning is very true.
I suppose it is natural to think like that since that presents the greatest possibility for a different outcome. It's more intersting to see what Germany would have done differently and won instead of thinking what the allies could have done differently...and won a little bit earlier. I guess it's just the way we are wired. The underdog is always more interesting.

As for industrial caacity I can only say that I think the US capacity is staggering. It was quite an achievement.
Just ponder for a moment Germany in this regard. Over a 1,000 submarines constructed, the bulk of which in the war years.
I a large number of varieties.
Also when it comes to aircraft...33,000 Bf 109s were produced in the space of ten years in, I belive ten different variants. And thay was only one aircraft type of many. Had Germany focused industrial capacity on the good stuff...

Looking at the production figures and comparing them with today is very interesting(even though that comparison isn't very fair.) no matter what country.

[Zie Chuckinator]

I think the German strategy could have worked, but they had a short window of opportunity to get the job done, which lasted maybe through early 1942. They simply didn't have enough boats at the start of the war to make a knockout blow, and it's remarkable that they did as well as they did.

To be fair to the Germans, while everyone knew that America's industrial might was massive, I don't think anyone (including us) foresaw just how incredible a force we would be. One Liberty ship, the Robert E. Peary, was completed in about five days, and we built over 2,500 Liberty-class transports alone! We produced over 80,000 Sherman tank chassis. We turned out staggering numbers of P38s, P40s, P47s, P51s, etc.

So really, the Germans were fighting a losing battle. Had they not invaded Russia in '41 they might have stood a better chance, but they spread themselves too thin and then had to add to their troubles an America whose productivity was increasing on average 40% a year from 1942-45.

God bless america... and no where else! lol jk.

[Ula Jolly]

Reckon I heard somewhere that in 1942 or so, the American navy's expense budget for production of escort vessels, namely destroyers, was the size of an entire peace-time naval budget. Can't confirm it, but I don't think it's very untrue. America came late, but boy did she come. (punpunpun)

[Sarge McSarge]

I remember a quote from someone in the Germay military early in the war and it went something like this
"We (Germay armed forces) can beat any country in the world but we can't beat every country" and in the end that was what it came down too. British stubborness, US manufacturing, Russian attrition. If Germany had put all its resources into a one front war the result would have been a lot different. Hitlers main target was Russia but without taking Poland attacking Russia would have been too hard. An attack through the Czechoslovakia , Hugary, Romania route would have been a logistical nightmare and impossible to conceal so Poland was necessary but of course that brought in France, Britian and the British Commonwealth countries. They should have just stayed at home and built the country up into an enconomic giant and then they could have bought any thing they wanted. Of course that line if thought does not appeal to megalomaniacs.

Sarge

[pampanito]

Just ponder for a moment Germany in this regard...33,000 Bf 109s were produced in the space of ten years in, I belive ten different variants. And thay was only one aircraft type of many. Had Germany focused industrial capacity on the good stuff...


Yet numbers alone are not a proof of success. This huge output of Bf109s is a good example. By the end of 1942 the Bf109 was no longer a match for some Allied fighters, but the daily replacement needs of the front-line squadrons were so enormous, that Germany could simply not afford to stop or drastically reduce its Bf109 production, in favour of more advanced models. The same was true for tanks, it would have been wonderful for the Germans to equip all their armoured divisions just with Tiger and Panther, but this would imply a drastic descent of overall tank production until the factory lines were changed, so a lot of Mark IVs were still being produced in the last year of the war.
Japan faced exactly the same problem, they already had fighter planes much better than the Zero in 1944, but production could not be massively re-directed because the huge front losses had to be satisfied.

USA and the USSR had not this problem, they had enough production capacity to keep producing the needed replacements, and also for putting the more advanced weapons into line.
Some people still believe that plane for plane or tank for tank, Germany always had the upper hand, and that she was just defeated by superior numbers. That's simply not the case; in 1945 the USSR had in service tanks like the JS-1 better that anything the Panzer divisions could field, and the American P-51s were able to shot-down any plane the Luftwaffe could put in the air. And don't believe the Me-262 could have won the war by itself... ;)

[P_Funk]

I think that the biggest "what ifs?" are:

1. What if Hitler had waited until 1945 to start his conquest when the German Navy alleged that it would have been ready?

2. What if Doenitz had been given the resources he had required at the very beginning of the war?

3. What if Goering hadn't been such a prat and had shared his air power with the U-boats (this would be hand in hand with #2)?

4. (here's a really fun one) What if Churchill had not returned to take command?

Realistically the war, as far as the U-Boats were concerned, needed to be won in the first 2 years or never at all. Their only hope after their early failures was the types XXI and XXIII boats and they came too late.

[pampanito]

I think that the biggest "what ifs?" are:

1. What if Hitler had waited until 1945 to start his conquest when the German Navy alleged that it would have been ready?

2. What if Doenitz had been given the resources he had required at the very beginning of the war?

3. What if Goering hadn't been such a prat and had shared his air power with the U-boats (this would be hand in hand with #2)?

4. (here's a really fun one) What if Churchill had not returned to take command?

Realistically the war, as far as the U-Boats were concerned, needed to be won in the first 2 years or never at all. Their only hope after their early failures was the types XXI and XXIII boats and they came too late.

But...
1. What if by 1945 the ugly truth of what was happening inside Germany had leaked to the outside world, and everyone knew what to expect from Germany and started rearming too?

2. What if the Royal Navy was given the needed resources and was not short of frigates and escort destroyers? Or if only USA had listened to British experience and had started a through convoy system along its Eastern coast and in the Caribbean as soon as war was declared?

3. What if Goering's Luftwaffe fared no better over the Atlantic that it did over Britain against the RAF? What if Allied long-range fighters had been deployed to Iceland, Ireland, Gibraltar, Madeira etc to shoot-down any recce plane Goering could send over the Atlantic?

4. What if Eisenhower had been designated CinC, Atlantic Air and Sea Forces?

As you see, 'what if...' are truly endless, and every one of them can trigger a lot more... :hmm:

[Nopileo]

Well according to a large number of scientists, there are infinite numbers of paralell universes, where the results of every possible decision/event exists. Makes your head spin, eh? :doh:

But seriously, what if the leaders of the world discovered that most conflicts could be solved diplomatically, much like the trend is these days? No SH3 would exist then! :damn: ;) :hmm:

[Gorduz]

My biggest what if is:
What if Hitler had gone straight for USSR instead of helping the italians with Jugoslavia? This prosponed Opration Barbarossa several month's. Without that detour, the wehrmacht would have reached moscov in 1941. I wonder how that wound have worked out...

[pampanito]

My biggest what if is:
What if Hitler had gone straight for USSR instead of helping the italians with Jugoslavia? This prosponed Opration Barbarossa several month's. Without that detour, the wehrmacht would have reached moscov in 1941. I wonder how that wound have worked out...

Remember that Napoleon reached Moscow in 1812, someone burned it (the French or the Russians, or possibly both)... and nothing happened. No Russian surrender came, and Napoleon had to retreat from a ruined capital when his lines of communication were cut by General Winter and the Cossacks. The same could have happened in 1941, I doubt Stalin would have remained in Moscow.
Also, failing to come to Mussolini's aid in his disastrous Balkanic campaign could have brought an irated reaction by the Italian dictator, and perhaps even marked the end of the Axis Rome/Berlin.
More 'what if'...

[Mike 'Red Ocktober' Hense]

i think that Hitler's biggest mistake was the Russian campaign... this was surely the beginning of the end...

and, as far as the Battle For The Atlantic goes... the Uboat campaign in the Atlantic was not so much effective strategically as it was as a propaganda success...

i think that Churchill was a pragmatist... and it was he who said something about the only thing he really ever feared was the uboat menace... or something along those lines...

but, surely there were other naval and non naval threats to the convoys that also had to be countered in order for the US to supply the European allies... i don't think that any one factor was a decisive one...

but, i do believe that if the Kriegsmarine had subs on the level of the XXI a few years earlier... and that Hitler hadn't open up a second front... supplying the British isles by sea would've been a far more perilous undertaking...

some people think that super weapons don't win wars... i tend to disagree... to a point that is... England couldn't have withstood a continuos onslaught of V1,V2s and a naval submarine blockade for any sustained period...

the way these weapons were employed was strategically faulted in a lot of cases... but the subs were used to a high level of effectiveness... if they only accepted the facts that the codes were broken, and that allied radar worked... things could've been different for the Reich...

i do seem to contradict myself here a bit though... the breaking of the codes and radar... not super weapons by any means... but effective developments which had a significant impact on the war in Europe...

hhhmmmm....


--Mike

[joea]

My biggest what if is:
What if Hitler had gone straight for USSR instead of helping the italians with Jugoslavia? This prosponed Opration Barbarossa several month's. Without that detour, the wehrmacht would have reached moscov in 1941. I wonder how that wound have worked out...

Remember that Napoleon reached Moscow in 1812, someone burned it (the French or the Russians, or possibly both)... and nothing happened. No Russian surrender came, and Napoleon had to retreat from a ruined capital when his lines of communication were cut by General Winter and the Cossacks. The same could have happened in 1941, I doubt Stalin would have remained in Moscow.
Also, failing to come to Mussolini's aid in his disastrous Balkanic campaign could have brought an irated reaction by the Italian dictator, and perhaps even marked the end of the Axis Rome/Berlin.
More 'what if'...

Hmmm yet the Soviet Union of 1941 was a different thing than Tsarist Russia of 1812. A much more centralized state, I believe all the traffic/rail hubs passed through for one thing. Would have been far more serious at any rate than Napoleon taking Moscow (don't forget St. Petersburg was the capital in 1812).

[gdogghenrikson]

"what if" I made a time machine and I shot hitler in 1938!! :rotfl:

[Mike 'Red Ocktober' Hense]

you did...

but that was in an alternate continuum... and we are stuck in this one for the time being...

:-j :-j :-j :-j

--Mike

[August]

The book i'm reading "Escort Commander" by Terrance Robertson quotes 21 million tons of shipping, or 4500 ships, lost during the war with 15 million tons, or 2775 ships, sunk by U-Boats.