WWII submarines...which was the better one?

[Soren]

Glider,

I'm in a hurry so I'll just address your comments the Type XXI.

The Type XXI featured much better habitability than any US boat. Fitted with an automatic schnorchel several airconditioning systems the boat was continously vented and kept odour free while temperature was kept at a constant comfortable level. Besides this the Type XXI boat featured large crew comfort areas as-well as multiple showers, large storage freezers, kitchens, bathrooms etc etc..

The Type XXI was unequalled in every way..

 

[Glider]

Glider,

I'm in a hurry so I'll just address your comments the Type XXI.

The Type XXI featured much better habitability than any US boat. Fitted with an automatic schnorchel several airconditioning systems the boat was continously vented and kept odour free while temperature was kept at a constant comfortable level. Besides this the Type XXI boat featured large crew comfort areas as-well as multiple showers, large storage freezers, kitchens, bathrooms etc etc..

The Type XXI was unequalled in every way..

The Fleet boats had the air conditioning, messing/recreational areas away from the sleeping areas (don't know how close that is to crew comfort areas), freezers, showers not baths and well equipped kitchens.
I have a description of a British 'S' class captain who was sent to the Pacific to fight the Japanese on his first visit to a Fleet Class Boat. He couldn't believe it, he had never having seen anything like it and said he felt that he something dead and smelly that the cat had brought in.
It might not be quite the same as the Type XXI but it was light years ahead of the Type VII and Type IX.

There is one mistake on my last posting. The depth statement was wrong. The last Fleets had an operating depth of 450ft and a crush depth of 750ft, I noted the wrong figure. Apologies for this.

 

[Soren]

The Type VIIC Type IX boats all featured airconditioning as-well Glider, but neither them nor the US ones were as effective as those placed in the Type XXI subs.

The torpedoes were also automatically loaded by hydraulics, seriously relieving the crew of some very time energy consuming hours in the torpedo compartment.

Besides this the Type XXI also featured the most advanced sonar equipment in the world. The system being used as a blind fire targeting system all the way down to a depth of 160 ft, and with pinpoint accuracy.

A similar system was fitted on some of the later Type IX VIIC boates, and the Allies never had anything to equal this.

 

[Glider]

The Type VIIC Type IX boats all featured airconditioning as-well Glider, but neither them nor the US ones were as effective as those placed in the Type XXI subs.

The torpedoes were also automatically loaded by hydraulics, seriously relieving the crew of some very time energy consuming hours in the torpedo compartment.

Besides this the Type XXI also featured the most advanced sonar equipment in the world. The system being used as a blind fire targeting system all the way down to a depth of 160 ft, and with pinpoint accuracy.

A similar system was fitted on some of the later Type IX VIIC boates, and the Allies never had anything to equal this.

I have never doubted that the Type XXI was the best by some margin and have said so a number of times. No disagreement there. I was comparing the fleet boats to the Types VII and IX.

Certainly the Type VIIc didn't have air conditioning in the way that we know it. It did have what was called 'Air Conditioning' but that was in the emergency ventalation system and consisted of Soda Lime in flat cans to be inserted into the ventalation system to clean the air of Carbon Dioxide.

I am also pretty confident that the Type VII didn't have any deep freeze for the food.

Re the Automatic loading of the torpedo's I don't see it. On the Type XXI which certainly did have this ability, the torpedo's were kept in a container that was lined up with the tube. The Hydraulics were able to 'push' the torpedos into the tube.
Attached is a photo of the forward torpedo area on U570. The spare torpedo's were in two layers on the floor of the compartment four on the bottom and two above them. Above the torpedo's was a false wooden floor on which the crew lived and their bunks can easily be seen. There is no way that the reloading could be done automaticaly, there is no room for the machinery and no way of lifting the torpedo's off the deck and lining them up. It would be far more complex than on the Type XXI.

 

[Soren]

Glider,

You seem to have misunderstood what I said:

The Type XXI was the ONLY U-boat of WW2 to feature a automatic reloading system.

I wasn't talking about the Type IX or VIIC's in my previous post, just the Type XXI.

But do note that the Type IX VIIC both recieved the advanced sonar targeting system. This device made the German U-boats the undisputed champs when it came to hunting down and sinking other subs.

 

[renrich]

My source on Type XXI: Poor structural integrity, crudely made, could not reach design depths and not as resistant to depth charges as earlier boats, hull failed at 800 feet, in reality failure depth was much less. Diesel engines underpowered. Design HP was 2000, reality was 1200 HP, max surface speed was 15.6 knots. Reduction in HP meant longer time to carry out full battery charge. Impractical hydraulic system. Most vital lines outside pressure hull, subject to leakage, corrosion and enemy weaponry. Could not be repaired while submerged. Poor habitability. Did not meet minimum standards of USN. "On paper" a good boat, not so in reality. How many kills was the type XXI responsible for?

 

[Soren]

Renrich, who'ever wrote that obviously hasn't got a clue what he's talking about.

The top surface speed of 15.6 knots was due to the smaller diesel engines put into the design, it had absolutely NOTHING to do with the engines not living up to the promised performance specifications. On electric engines the Type XXI reached speeds of 17.2 to 18 knots submerged, which was mindblowingly fast for a U-boat back then.

As to detectability, by virtue of the new hull design creep engines the Type XXI was by far the stealthiest U-boat on earth, being able to run on super silent at 7 knots, the absolute top submerged speed of most U-boats at the time. And on top of this the Type XXI was even more silent at this speed than any other running on creep.

The habitability of the Type XXI was none other than excellent, it was a luxury yacht compared to earlier types, and better than any US boat.

The hydraulic reloading system functioned perfectly and saved the crew a lot of precious time, the boat being able to fire 18 torpedoes in less than 20 minutes!

As to the rigidity of the hull, nothing wrong there either, all the boats which saw service had been tested down to 230m without any signs of problems. The hull could take it down to 280m no doubt, but regardless it would never be necessary or even attempted as nothing was guaranteed at such depths, hence all the deep sea test runs were down to 230m.

Now regarding the "kills" of the Type XXI subs, well Renrich, none ever saw combat, so go figure. Two got real close though (Both utilizing the Type XXI's excellent stealth capabilities):

Then on May 3 1945, the unthinkable, but inevitable happened. A message from BdU: Germany had surrendered. All U-boats were ordered to cease hostilities and were to sail to the nearest allied port under a black flag. Nevertheless, U-2511 had the British cruiser HMS Suffolk in its sights. Schnee carefully evaded the heavy escort screen, closed in to 600 meters of the cruiser, and raised the periscope. The torpedoes were primed, and he ordered the tube doors opened. As the British cruiser crossed the targeting crosshair on his periscope - instead of giving the order to fire, he simply cursed, lowered the scope, dived under the target and made off for Norway, unknown to those sailing above him.

The other Type XXI, Kptlt. Helmut Manseck of U-3008 had just sailed from Wilhelmshaven on May 3, 1945. Shortly after departing, the message of Germany's surrender was received, Manseck spotted a British convoy and carried out a dummy attack. He slipped away undetected and returned to port.

 

[Glider]

Have to agree with Soren on this posting, the habitability of the XXI compared to the US we can put to one side as they were both excellent.
There were some problems in the early days with the building due to distruption caused by bombing and training the crews took longer than the Germans hoped, but it was more a case of Senior Ranks being unrealistic than an inherrant design issue and the problems were overcome.

It should be remembered that the Type XXI was a brand new design, being built in a manner never tried before, stuffed full of technology which had never been installed before, needing tactics that had never been used before and all without a Prototype. It was only to be expected!!

But I emphasise that these were overcome and the performance figures met.

 

[Kurfürst]

Re: Sonar

Glider,

I`d suggest you read up Friedman on post-WW2 US boats. He leaves very little doubt about how even the best USN sonars in 1945 related to the GHG. Basically, the latter was in an entirely different class, and post war US (Soviet, Federal German etc.) sonars were rip-offs and improved models of it.

When I`ll have a bit of time, I will type the text for you guys..

 

[renrich]

Soren, the guy who wrote that is one of the foremost and prolific of all writers in the world on WW2 submarines. I am sorry that you don't agree with him. His book that I quoted him from is voluminous and extremely well researched, referenced and footnoted. Unfortunately this particular part of the book is footnoted back to his first volume which I don't have. However as is most of the information in the book, I am sure it comes from sources well recognised and probably based on research by the Allies after the war. Would you mind telling me why the Germans would build an advanced sub like the XXI that was slower on the surface than their other subs? I do believe that I will stick with his data until a more credible authority come along. By the way this author served in subs during WW2. Also by the way, I went through a fleet boat, Grouper, I believe, at Mobile and I don't see how any WW2 sub could be called habitable. I am, or was, a little over 6 feet tall and I don't believe I could fit in the officer's bunks.

 

[Glider]

Renrich, can I ask the name of the book please. I am not doubting it but it does go against anything that I have read and I wold like to try and get a copy.
I have two books that go into detail about German Submarines and two more that cover the undersea war in general and none of them mention the porblems you mention above.
The question you ask re the surface speed doesn't suprise me as the Type XXI was designed for underwater speed and like any modern submarine, is faster underwater than on the surface.
I haven't been on a US Fleet Boat but I have been on a British A class which is of a similar period. Like you I found it cramped, but there is no doubt from the veterans who I was with, that they found the A class very comfortable.

Re habitability, the attached may be of intrest. You may want to compare it to the photo I posted of the Type VII forward torpedo room where men slept.
U-Boot Type XXI in Detail

 

[renrich]

"Hitler's U-Boat War, The Hunted, 1942-!945", Clay Blair. There is an earlier volume which I don't have. This is a library book and I have checked it out twice for this discussion. Most of the info in the book is from several sources, British, German and American. He has published at least 25 books, 100s of magazine articles. "Silent Victory: The US Submarine War Against Japan" by Blair is a 2 volume work that I own but it is packed. I have 2 other books on the Atlantic sub war checked out from the library now but can already tell they will not be as authoritative as this one.

 

[Soren]

Sorry Renrich but Clay Bair isn't a good source on German subs, plus he's obviously a very biased individual as his descriptions of the Type XXI are complete and utter hogwash. His book is rather old as-well IIRC.

Try the book by Rossler I mentioned earlier, absolutely the most historically technically in depth detailed book on the German subs out there! Awesome read!

 

[renrich]

I suspect that Blair's info about the type XXI is based on reports of tests conducted by the Allies post war on captured boats. I don't believe he would lie about these matters. His reputation would be at stake. For instance the info posted by Glider(most interesting) states that the diesels generated 2000 HP. Blair stated that the diesels were designed to be 2000 HP but because the superchargers did not meet specs the actual HP was 1200. His remarks about construction indicated that the boats were built in pre fab sections and then assembled and that the different sections did not fit well together with sloppy welds. Perhaps the boat examined by the Allies was an early production model(or maybe built during deer season) My suspicion is that the performance of the Type XXI that Soren is quoting is based on the design specifications and don't necessarily represent the real world performance of the boats that first came off the ways. Obviously the engines of the boat in Glider's post have been upgraded to the original design specs. 1200HP to 2000HP. Would it be surprising if the first production boats did not meet the quality and performance standards expected especially under the wartime conditions those boats were built under. I have owned many German autos from 1972 to 2000 and none of their AC systems came up to minimum standards for the US. Hope the AC in the XXIs worked better than them. LOL

 

[Kurfürst]

Basically it would be interesting what Blair`s claims regarding the Type XXI are based on.

Given the author`s controversial reputation, and the fact he is generally prone to a revisionist attitude on all subjects he wrote on, ie. while being so fond of myth-busting he goes over to the other extrme and creates his own myths, I would say it`s not unreasonable to believe Blair`s comments on the Type XXI are more based on his personal inclination to 'bust' the 'myth of the super-XXI' (which may have been overhyped, and started an unhealthy towards it in Blair), and fall over to the other extreme descibing it as a complete piece of crap. It`s not about the XXI, from what I`ve read Blair does that to many subjects in his books, kicking things/people aggressively he doesn`t like.

As for submarine design - the Germans had obviously far more experience on this field than everybody else combined. I would be awfully surprised if they would have made such fatal errors as Blair suggest.

As far as Blair record of greasing torpedoes during WW2 on a Fleet boat - well that kinda fells far from being an engineer and designing operational submarines isn`t it..

 

[renrich]

You make good points Kurfurst. If I can get ahold of his first volume perhaps I can find out where his info on the snort and the XXI came from. However his notes on the snort are backed up by other authors and there are numerous mentions in the German patrol reports of aborts by boats having diesel engine problems and we know that the diesel engines in the Scheer class gave a lot of problems and for that matter there are many mentions of diesel engine defects in American patrol reports. I personally have no doubt that an advanced design such as the XXI would not immediately meet all design specifications and there was not time to do sea trials and get all the bugs out. For that matter, I just read a report on testing a production line F6F5 that stated there were a number of problems with the power plant which kept it from reaching full combat power. That AC had a uprated version of the same engine that was in the F6F3. I don't think it is realistic to think that a brand new design of almost any machine is going to hit the pavement with everything working as planned. By the way, the first operational submarines were built in the US so they had a bit of experience with subs also just like ironclads and powered flight.

 

[Glider]

I suspect that Blair's info about the type XXI is based on reports of tests conducted by the Allies post war on captured boats. I don't believe he would lie about these matters. His reputation would be at stake. For instance the info posted by Glider(most interesting) states that the diesels generated 2000 HP. Blair stated that the diesels were designed to be 2000 HP but because the superchargers did not meet specs the actual HP was 1200. His remarks about construction indicated that the boats were built in pre fab sections and then assembled and that the different sections did not fit well together with sloppy welds. Perhaps the boat examined by the Allies was an early production model(or maybe built during deer season) My suspicion is that the performance of the Type XXI that Soren is quoting is based on the design specifications and don't necessarily represent the real world performance of the boats that first came off the ways. Obviously the engines of the boat in Glider's post have been upgraded to the original design specs. 1200HP to 2000HP. Would it be surprising if the first production boats did not meet the quality and performance standards expected especially under the wartime conditions those boats were built under. I have owned many German autos from 1972 to 2000 and none of their AC systems came up to minimum standards for the US. Hope the AC in the XXIs worked better than them. LOL

There is no doubt that some of the early boats did suffer from a lack of quality contol. The boats were built in prefabricated sections and most of these were inland. As they were inland they wouldn't have been built by people experienced in this field. The inevitable result being that they didn't fit as well as they should amongst other reasons and any weakness is a submarine, for obvious reasons is a danger. However this was addressed and quality improved considerably but at the cost of time, the one thing Germany didn't have.
This was one reason why the first Type XXI commissioned in mid 1944 but only a couple of war patrols were started by the wars end. The other main reason was the level of training required by the crews.
I cannot comment on the engines but I admit, I would be suprised if they were as poor as Blair reports, Germany were recognised experts in this field.

The following posting is one that I belive to have the ring of truth. It recognises the problems that would be found in a rushed production of such a complex item, as well as the success of the overall design.

German Type XXI U-Boat Elektroboat UBoat - history, specification and photos

 

[renrich]

Blairs words: "Hurriedly prefabricated in 32 different factories that had little or no experience in submarine building, the eight major hull sections of the type XXI were crudely made and did not fit together properly." Sounds like what you said Glider. On the engines: " The new model 6 cylinder diesels fitted to the type XXI were equipped with superchargers to generate the required horsepower. The system was so poorly designed and manufactured that the superchargers could not be used." This loss of horse power resulted in a substantial decrease in surface speed as well as speed submerged while using the snort as well as taking longer to charge the batteries. I am paraphasing him here. Sounds credible to me. On the snort:" A snorting u-boat was usually rendered "deaf" and "blind" because the diesels made a terrific racket and the periscopes could not be raised because of vibration and other problems." This referred to all snorkel equipped boats. " By sonar and eyesight, Allied anti sub forces detected u boats by the noise and leaking exhaust smoke of the snorkel." Again sounds credible to me.

 

[Soren]

Blair is biased Renrich, thats quite clear from his comments as he often twists the actual facts, and he never once says what his source is.

And no Renrich I'm not listing promised spec's, I'm listing listing the mean results achieved in several trials conducted with different boats.´

Surface speed was established as 15.6 to 15.7 knots, while submerged speed was established as 17.2 to 18 knots. Crush depth was calculated to be over 280m, diving trials were conducted successfully down to 230m without any problems.

I have owned many German autos from 1972 to 2000 and none of their AC systems came up to minimum standards for the US.

What a lousy set of examples you have owned then Renrich, cause I can tell you that over here in Europe American cars are and have always been regarded as very lowstandard in quality compared to German cars. I have friends who own several American cars, and all they are about is power sound, both of which they have plenty off, but the excitement disappears quickly as soon as you try to take a curve with one or have to play its mechanic. The AC systems in German cars work perfectly well, but dependng on the features you want you also have to pay accordingly, most German cars from 2000 and up also feature much more advanced climatic control systems with features like different air temperature sections inside the car etc etc...

The best quality cars you can buy have always been German Japanese.

 

[Glider]

Blairs words: "Hurriedly prefabricated in 32 different factories that had little or no experience in submarine building, the eight major hull sections of the type XXI were crudely made and did not fit together properly." Sounds like what you said Glider. On the engines: " The new model 6 cylinder diesels fitted to the type XXI were equipped with superchargers to generate the required horsepower. The system was so poorly designed and manufactured that the superchargers could not be used." This loss of horse power resulted in a substantial decrease in surface speed as well as speed submerged while using the snort as well as taking longer to charge the batteries. I am paraphasing him here. Sounds credible to me. On the snort:" A snorting u-boat was usually rendered "deaf" and "blind" because the diesels made a terrific racket and the periscopes could not be raised because of vibration and other problems." This referred to all snorkel equipped boats. " By sonar and eyesight, Allied anti sub forces detected u boats by the noise and leaking exhaust smoke of the snorkel." Again sounds credible to me.

Re the quality of the build I understand that this was fixed by the second half of 1944 but as I said this was time the Germans didn't have and with training taking nearly 6 months, means that the end of the war is on hand, which of course, it was.
As I said I cannot comment on the engines, it could well have been the inevitable teething troubles of introducing a new design to quickly without sufficient testing. I don't know

On the snort I do have some observations and believe the problem, shall we say, to be overstated.
Diesel engines produce smoke, its a fact and this will in theory be visible and act as a marker. They are also noisy, also a fact.
First the smoke - In reality two things would almost completely mitigate this.
a) how many times have you been at sea and there has been no wind - almost never I suspect, in the oceans of the world there is nearly always a wind. Any wind would disperse the smoke so it would be almost invisible.
b) type XXI subs could raise their sensors and radars whilst submerged to check that nothing is around

Then the sound - Type XXI submarines had superb passive sonar well in advance of anything else in the world. They would be able to ensure that there are no naval vessels around.

I am not saying they were imune, certainly not, but they stand an excellent chance of using the snort and not being attacked. Its a whole lot safer than surfacing, thats for sure.