Best Designed Ship of WWII

[wernerpruckner]

In his ways Dönitz was right - the best ships for commerce raiding - for the German Kriegsmarine - was the u-boat.
 
look at the amount of everything you would have needed for a H class ship ( in RL they even invested lots of money material in them )

[Raverdave]

ORIGINAL: LowCommand



As a note, most historian's and Eisenhower, came up with a list of "The" weapons that won WWII. It usually runs something like:
LST
Liberty
DUWK
Duce and a half
Bulldozer
C47
M1 Rifle

Note that only the M1 is normally considered a weapon.

DUWK and M1 ???????? Ha ! What a load of cobblers !

[herwin]

ORIGINAL: swift

In his ways Dönitz was right - the best ships for commerce raiding - for the German Kriegsmarine - was the u-boat.

look at the amount of everything you would have needed for a H class ship ( in RL they even invested lots of money material in them )

Warships are expensive. What does it take to build an armoured corps?--about 500 tanks at 50 tons each plus 10000 trucks and medium guns at 5 tons each, or 75,000 tons of steel. Use that as your comparison.

Suppose you're building two carriers, two battleships, four heavy cruisers, and eight destroyers a year. That would be about 354,000 tons of steel per year. Add about 32 liberty ships, taking the total to a million tons of steel a year to support them. Finally look at the steel production of your average nation involved in WWII...

See why you might not want to be a naval power?

[rtrapasso]

ORIGINAL: mikemike

ORIGINAL: rtrapasso

In Re: Type XXI - see Clay Blair's book Hitler's U-Boat War - The Hunted 1942-1945 (Blair has been accused of being way over the top in being pro-U-boat, so if anything he is tends to be too forgiving of their faults) - pages 709-710 (paperback edition) - thi s passage from page 710 (discussing the faults of the type XXI): "Impractical Hydraulic System. The main lines, accumulators, cylinders and pistons of the hydraulic gear for operating the diving planes, rudder, torpedo-tube outer doors, and antiaircraft gun turrets on the bridge were too complex and delicate and were located outside (emphasis in the original text, not mine) the pressure hull. This gear was therefore subject to saltwater leakage, corrosion, and enemy weaponry. It could not be repaired from inside the pressure hull."

Blair devotes another section describing the finding of a U.S. assessment team.

Other problems of the Type XXI mentioned:

- Poor Structural Integrity (actual diving depth was less than the later type VII).
- Underpowered Diesel Engines
- Poor Habitability and Sanitation (i.e.: drinking and washing water was interconnected.)

Other authors have mentioned poor surface maneuverability, but this is a problem common to streamlined subs in general.


As for the stern weakness of the Bismarck and other large German ships - several developed rather catastrophic failure (not just the CA mentioned) but it is late and i should have been asleep 1 hour ago, so i won't pursue this at the moment... [>:]

I've never seen that book you refer to, but others have commented on Clay Blair's position. The hydraulics system of the Type 21 was overly complicated, one of the many "clever" design features inherited from the Type 18 which was designed by the Walther team that comprised able engineers, but nobody who had any experience with design or operation of submarines. The hydraulic actuation of the rudders had to be completely redesigned before it worked properly. But I've never heard of the system being substantially outside the pressure hull - you know that one of the boats was used for more than twenty years postwar as a test&development vehicle which tends to suggest that long-term serviceability of those systems can't have been much of a problem. As I said, had vital systems been vulnerable to that extent, the type would never have been accepted for service, not even under the desperate circumstances prevailing.

I read the relevant passages in Eberhard Rössler, "U-Boottyp XXI" (U-Boat Type XXI), a very detailed monograph, where I found this (my translation) " Difficulties were especially caused by the hydraulic equipment to retract and move the forward diving planes which was fitted outside the pressure hull. Great trouble was caused by contamination of the hydraulic fluid by seawater which led to damage to the pumps. This occured especially with the AA turret drives ... which therefore late in 1944 received their own, isolated hydraulic circuit." Meaning, yes, parts of the hydraulic systems were outside the pressure hull, but it was obviously felt that this would not negatively impact the combatworthiness of the type.

BTW, the mechanism of the forward planes was copied from the Dutch O25 class. The Dutch apparently didn't see any particular problem with this arrangement, either.

U.S. assessment teams are always dismissive of foreign kit, so that evaluation doesn't surprise me. I assume they didn't mention the torpedo reload arrangement that allowed firing the second full salvo just eleven minutes after the first. Does anybody know how long it took the crew of a Gato to reload all six tubes?

That the strength of the pressure hull wasn't what was intended was suspected in 1944 already - curse of the double-bubble hull: at the time no mathematical methods existed that would have allowed precise calculation of such a pressure vessel, and the lower lobe of the pressure hull was designed by estimate. Design diving depth was 133 metres, meaning a combat diving depth of 220 metres and a crush depth of 330 metres, which was comparable to the VIIC boats. Tests in a pressure dock showed that the lower lobe of the hull collapsed at a pressure of 31,5 atmospheres (equivalent to a depth of about 315 metres), but no type 21 went deeper than 220 metres, deep-diving trials in Norway were terminated at that depth because the "pressure-tight" emergency raft containers imploded at that depth.

Underpowered diesels? This were not fleet submarines, designed for maximum surface speed. The diesels just had to be powerful enough to recharge the batteries in an acceptable time. The diesels were turbosupercharged 6-cylinder versions of the MAN M9V 40/46 which powered the Type IX boats, developing 2000 hp each. Unfortunately, the afterthought of a snorkel fitted to the Type 21's had an inadequate cross section that choked the superchargers thus cutting output to 1400 hp, which was still adequate, if not ideal, for the boats. BTW, the first installations of the M9V 40/46 were U.S. Submarines Cachalot and Cuttlefish, whose crews were unable to properly operate and maintain the engines. The crews of more than 170 Type IX boats never had that kind of trouble. Problem of the engines? I don't think so.

As to habitability, the Type 21's probably couldn't compare to the floating ice-cream parlors the USN was operating, but they were worlds better than the Type VII and IX boats; certainly their crews had no complaints. On the other hand, if the US boats had tried to operate in the North Atlantic in the same way as the U-Boats, the ASW forces would have caught them routinely on the surface, because their crash dives could have been timed with a tear-off calendar. US submarines either attacked completely submerged or stayed on the surface and fought it out. In the North Atlantic they wouldn't have been any more successful than the Italian boats.

Maneuvering the XXI's on the surface was even more awkward than caused by the hull shape alone because the propeller shafts were so widely splayed outwards. The turning circle was double that of the Type IX boats; to minimize the turning radius, the inner propeller had to be run faster than the outer propeller, which is the opposite of normal behaviour.

I'll freely concede that the Type 21's were a hastily slapped-together contingency design with many flaws and a frequently sub-optimal quality of construction, but they would have caused a whole new world of hurt for Allied ASW forces if they had gone into combat in significant numbers.

Dismissing someone's first-hand observations, as well as research seems to be ignoring the facts: i have shown references (which included Blair's first hand observations) that the hydraulics were on the outside of the pressure hull - the onus is now on you to show otherwise, not just by gainsaying it by saying "they wouldn't have been so stupid".

As for the diesels: they were underpowered because they could NOT hope to recharge the enlarged batteries the XXI in a decent (i.e. - survivable) amount of time - at least according to what i've read about it. The amount of current needed to recharge the battery would have required a diesel engine proportionally as large as the increase in battery size... the diesel on earlier submarines were pretty much matched to allow this (barely - usually it was a close run thing to get enough power to move the ship on the surface and to allow battery recharge in sufficient time - made worse at high-latitudes during the summer.)

i'll also point out the snorkels, while often perceived as a solution to the recharge problem, left the sub pretty much blind and deaf while running the diesels. Allied radar had improved to where they could detect the snorkel masts - and if detected the U-boat could be attacked and destroyed, sometimes before they even had an inkling that they were in imminent danger.

As far as German diesels - the Germans had plenty of problems with them... many of the war reports mention the engines of ships breaking down at sea of the diesels necessitating the ships being towed... if they could be gotten to in time.

As for some of the first US boats having problems with their diesels: almost ANY new installation of any new technology in ANY navy is going to have problems...

Pointing out the flaws in another design (as has been rather prone to happen on this thread) does NOT improve the design you are championing as "the best design" (unless two designs are in direct competition for the "best", which has not been the case here).

However: crash drive times in US subs were poor at the beginning of the war, but from the several (well, numerous, actually) first-hand accounts i've read, they usually got them down to 30 seconds or less with training (and non-standard procedure revision)... and the US subs were generally far larger than the type VII or XXI. Smaller S-boats, although out of date, had very good crash-dive times afaik.

Your last paragraph, though, makes my original point: the type XXI's were NOT the "best designed ships of WWII".

[rtrapasso]

..

[Tiornu]

They might run through the denmark straight down to the Rio de la plata and back with a 20% backup for battle

Which destroyers and cruisers are going to escort them? The Germans were left with these massive investments which could prowl the world's seas only on their own.

To give you an idea of the problem the KM had working out sane missions for its ships, the design mission of the Prinz Eugen and its sisters was to attack French troop convoys in the Mediterranean.

That's interesting. Can you cite a source?

[Historiker]

Which destroyers and cruisers are going to escort them? The Germans were left with these massive investments which could prowl the world's seas only on their own.

What do you need them for?

[Nikademus]

ORIGINAL: Dili

The size of the holes is mostly the same(for similar effective detonations) in all similar ships since the outside hull is always weak, what matters is what is behind it or not and if it can stop the water.

Except in those cases where it isn't. What was behind it in this case proved insufficient to stop massive progressive flooding. Regardless, the main point was that damage has a far greater reach than you are willing to concede.

I dont dismiss the crew, italian High Command did, they were retrained and were reorganized(Source: Orizzonte Mare,Corazatte Vittorio Veneto Vol.2, pag.15), also it is my bias that a ship looses efficiency when in Harbour. For example Vailant and Queen Elizabeth might have not been sunk in Alexandria if the explosion would have occured at sea. Note that in image i have linked(for some reason the forum didnt let me upload yesterday) you can see in all images how the ships went in the water after those hits.

I'm not talking to the Italian High Command, I'm speaking to you, and it was you that claimed it was basically the crew's fault that the ship suffered as much as it did. People usually argue using source but are still expected to make their own conclusions. My conclusion is that blaming the crew is an inadequate and convenient explanation. Valient and QE would almost certainly have sunk had they somehow suffered that damage they did while in the same sea conditions as Bismarck was, more so given the class was weak vs. underwater damage.

In Taranto only one hit was in Pugliese system, the hit below A turret while there the Pugliese system is already in minor size. To make any judgement we would need information we dont have: how much water went there.

Enough water to submerge the forcastle. The TBD system was narrower abreast the turrets vs the machinery spaces due to space limitations which were acute given the bulkiness of the system. This reduced it's efficiency but didn't make it "minor." It still failed which was the point. Designers build in hope and expectation, but reality often is a brutal teacher.

[Second:HMS Nelson is evidence that steering with engines only is no problem (and not even including auxiliary rudders), due to enemy attacks(U-56 one of them a torpedo that didnt detonated but stuck the rudder, or just because the fragile thing broke and had some times to resort to propeller only steering.

The original question was could a damaged warship in the stormy North Atlantic conditions Bismarck was faced in steer adequately on props only to escape fate? If steering on props alone was universally "no problem" then warships wouldn't require rudders to begin with.

Strange reference since Bismarck rudder size was tiny and was only one...(post edit: i was wrong they were two small ones).
Littorios were known as very maneuverable. The auxiliary rudders were almost like another rudder 38m2 Vs 32m2. Also as i have said i dont think a design flaw is something that have clear trade offs and that they seem sensible even if i favour other option.

What were the dimensions of the rudders of the Bismarck, KGV and North Carolina?

I don't recall saying that Littorio was unmaneuverable, the commentary on her design as per Garzke offered a good answer to your earlier question on why would the Germans (not to metion other nations) not build a slew of aux rudders vs a more traditional 2-rudder arragement....that being that the two rudder arrangement allows greater maneuverability vs the arrangement chosen for Littorio. Littorio as mentioned might have avoided more hits had she such an arrangement. Instead redundancy was preferred. Either way, no design FLAW in either ship class, design choice.

There is remarkable similarity between the Bismarck damage and a similar torpedo hit on the stern of Prinz Eugen on 23 February 1942. Dr. Erwin Strohbusch, who directed the repairs of this heavy cruiser in Norway, wrote to us that this incident, and an earlier one on the armored cruiser Lützow, whose stern also collapsed from a torpedo hit, indicated a structural flaw in the stern design of German armored ships, heavy cruisers, battleships, and battlecruisers. Improvements were made to the stern structures of Admiral Hipper, Lützow, Tirpitz, Admiral Scheer and Scharnhorst during 1942-1943.

This is a seperate issue.

[herwin]

ORIGINAL: Tiornu

They might run through the denmark straight down to the Rio de la plata and back with a 20% backup for battle

Which destroyers and cruisers are going to escort them? The Germans were left with these massive investments which could prowl the world's seas only on their own.

To give you an idea of the problem the KM had working out sane missions for its ships, the design mission of the Prinz Eugen and its sisters was to attack French troop convoys in the Mediterranean.

That's interesting. Can you cite a source?

The design folder for that class. Nathan Okun had me translating declassified Kriegsmarine documentation about thirty years ago, and he noticed it.

[Dili]

Except in those cases where it isn't. What was behind it in this case proved insufficient to stop massive progressive flooding. Regardless, the main point was that damage has a far greater reach than you are willing to concede.

What those case where it isnt? a year later the same ship? did you saw the same ship atitude after the second time torpedo. Well it was much better than for example HMS Nelson with also one torpedo in same area.

I'm not talking to the Italian High Command, I'm speaking to you, and it was you that claimed it was basically the crew's fault that the ship suffered as much as it did. People usually argue using source but are still expected to make their own conclusions. My conclusion is that blaming the crew is an inadequate and convenient explanation. Valient and QE would almost certainly have sunk had they somehow suffered that damage they did while in the same sea conditions as Bismarck was, more so given the class was weak vs. underwater damage.

Are you out of your mind? I "clained" that because i have source that said it(do you want a scan?) and makes sense since subsequent torpedo hits the ship class performed well.

Enough water to submerge the forcastle. The TBD system was narrower abreast the turrets vs the machinery spaces due to space limitations which were acute given the bulkiness of the system. This reduced it's efficiency but didn't make it "minor." It still failed which was the point. Designers build in hope and expectation, but reality often is a brutal teacher.

Did you saw what i wrote? seems not. Why it didnt happened later?

The original question was could a damaged warship in the stormy North Atlantic conditions Bismarck was faced in steer adequately on props only to escape fate? If steering on props alone was universally "no problem" then warships wouldn't require rudders to begin with.

So you don't know that requirement to maneuver for safety is not the same than full performance.

I don't recall saying that Littorio was unmaneuverable, the commentary on her design as per Garzke offered a good answer to your earlier question on why would the Germans (not to metion other nations) not build a slew of aux rudders vs a more traditional 2-rudder arragement....that being that the two rudder arrangement allows greater maneuverability vs the arrangement chosen for Littorio. Littorio as mentioned might have avoided more hits had she such an arrangement. Instead redundancy was preferred. Either way, no design FLAW in either ship class, design choice.

Your evidence for your conclusion is nil, since you didnt even came up with rudder size comparison or any other source. Also seems that you don't even know the reputation of Bismarck, that had a substandart maneuverality and was incapable of maneuvering with minimal safety even with rudder at 0 degrees with engines only. Another evidence of badly tough steering,propeller arrangement and the more i read why not to say the whole back end of the ship. Design Flaw.

[Tiornu]

The design folder for that class.

Do you still have the translation?

What do you need them for?

Good one!

[Nikademus]

ORIGINAL: Dili


What those case where it isnt?

You said torpedo hits produce the same hole in the same location every time. Except that it doesn't.

Are you out of your mind? I "clained" that because i have source that said it(do you want a scan?) and makes sense since subsequent torpedo hits the ship class performed well.

So in other words your saying parrot whatever you read online and don't think for yourself? Subsequent torpedo hits did not all come out rosy for this class either.

Did you saw what i wrote? seems not. Why it didnt happened later?

Because no Littorio class vessel absorbed 3 torpedo hits at one time after Taranto.

So you don't know that requirement to maneuver for safety is not the same than full performance.

So your not going to answer the question?

Your evidence for your conclusion is nil, since you didnt even came up with rudder size comparison or any other source.

Your the first person i've read say that Bismarck's rudder, then rudder(S) were "Tiny" which implies they were inadequate even when functioning. I was curious as to the source of such a claim, thus I asked simply, how do her rudders compare in size to her contemporaries? Your reply is that my "evidence is nil" yet your the one who made the implication.

Also seems that you don't even know the reputation of Bismarck, that had a substandart maneuverality and was incapable of maneuvering with minimal safety even with rudder at 0 degrees with engines only. Another evidence of badly tough steering,propeller arrangement and the more i read why not to say the whole back end of the ship. Design Flaw.

I know that Bismarck was an excellent seaboat with excellent stability that made her a very good gun platform even in the heavy swells of the Atlantic. This was more than a minor factor in her victory over HMS Hood and in striking PoW several times. You can call her difficulties via properllors alone a flaw though i don't consider it a major one anymore than with her steering arrangements.

any more comments you'd like to make about me?

[herwin]

ORIGINAL: Tiornu

The design folder for that class.

Do you still have the translation?

What do you need them for?

Good one!

Ask Nathan.

[goodboyladdie]

ORIGINAL: Nikademus

ORIGINAL: Dili


What those case where it isnt?

You said torpedo hits produce the same hole in the same location every time. Except that it doesn't.

Are you out of your mind? I "clained" that because i have source that said it(do you want a scan?) and makes sense since subsequent torpedo hits the ship class performed well.

So in other words your saying parrot whatever you read online and don't think for yourself? Subsequent torpedo hits did not all come out rosy for this class either.

Did you saw what i wrote? seems not. Why it didnt happened later?

Because no Littorio class vessel absorbed 3 torpedo hits at one time after Taranto.

So you don't know that requirement to maneuver for safety is not the same than full performance.

So your not going to answer the question?

Your evidence for your conclusion is nil, since you didnt even came up with rudder size comparison or any other source.

Your the first person i've read say that Bismarck's rudder, then rudder(S) were "Tiny" which implies they were inadequate even when functioning. I was curious as to the source of such a claim, thus I asked simply, how do her rudders compare in size to her contemporaries? Your reply is that my "evidence is nil" yet your the one who made the implication.

Also seems that you don't even know the reputation of Bismarck, that had a substandart maneuverality and was incapable of maneuvering with minimal safety even with rudder at 0 degrees with engines only. Another evidence of badly tough steering,propeller arrangement and the more i read why not to say the whole back end of the ship. Design Flaw.

I know that Bismarck was an excellent seaboat with excellent stability that made her a very good gun platform even in the heavy swells of the Atlantic. This was more than a minor factor in her victory over HMS Hood and in striking PoW several times. You can call her difficulties via properllors alone a flaw though i don't consider it a major one anymore than with her steering arrangements.

any more comments you'd like to make about me?

Is it just Dili you are inviting to make comments about you Nik, or can we all join in? [:)]

PS your Brothers could do with your help with a little rebuilding work that Matrix dropped in our lap...

[Gem35]

All of you are wrong!
I saw Sink the Bismark and it clearly shows the ship's crew thought of her as indestructable.[:'(]

[Nikademus]

Is it just Dili you are inviting to make comments about you Nik, or can we all join in? [:)]

PS your Brothers could do with your help with a little rebuilding work that Matrix dropped in our lap...

oh sure, i'm sure all the commentary will be ROSY and POSITIVE with tributes the same as when Bill Gates announced his retirement from the makers of the famous BLUE SCREEN OF DEATH. [:'(]

uhm.....what rebuilding work to you refer too?

[DuckofTindalos]

The Thread.

[Gem35]

T wants his 9k posts back so he will feel better.[;)]

[mikemike]

ORIGINAL: rtrapasso

Your last paragraph, though, makes my original point: the type XXI's were NOT the "best designed ships of WWII".

We're in agreement there: I would never claim that the Type XXI's were the best-designed ships of WWII - that was done by somebody else. The XXI's were an emergency stopgap design, in peacetime they wouldn't have gone past prototype without a major redesign, especially the pressure hull configuration would never have been approved; it resulted from the need to squeeze the giant battery into a given hull shape. But they weren't quite as bad as you seem to think, either.

No, I can't quote somebody saying "All was well with the hydraulic system". But I own a book by an (admittedly German) U-Boat specialist which describes the type XXI, its gestation, production, trials, and service history in detail, and while numerous flaws and bugs of the design are being mentioned (and the hydraulics were responsible for their share of problems), with the exception of the passage I quoted there is no mention of problems caused by the hydraulics being outside the pressure hull. This was the only U-Boat type to use hydraulics to any extent, systems in all other types were powered electrically, pneumatically (as was the snorkel in the XXI's, a system not part of the original design), or by muscle power. The German Navy was technically rather conservative, and such a digression from the norm would have been regarded with suspicion. I take the non-mention of the kind of problems you refer to as an indication that nobody saw noteworthy problems of that kind. However, I concede that possible long-term problems might have been rated less important at a time when U-Boats survived maybe 1.5 missions.

Running under snorkel, with a power output of 2x1050 HP from the diesels, it took 6 hours 12 minutes to completely recharge batteries discharged to 10% of the capacity. Tested by U2505 in December, 1944. Normally, the battery wouldn't have been run down that far, so recharge times would have been rather shorter, and even 10% of the charge would have let the boat run for almost seven hours at three knots. The final trials report remarks that "recharge times, both running on the surface and under snorkel, have been significantly shortened compared to conventional types, despite the very much greater battery capacity."

Your opinion that the snorkel had virtually no positive effect on the survivability and the operational opportunities of the U-Boats does surprise me a bit. If snorkels are so useless, why is everybody using them even today, when RADAR performance is several orders of magnitude better than in 1944? But there are people in this forum, ASW practitioners, who can tell you better than I could what the introduction of the snorkel meant for the U-Boats.

[rtrapasso]

Your opinion that the snorkel had virtually no positive effect on the survivability and the operational opportunities of the U-Boats does surprise me a bit. If snorkels are so useless, why is everybody using them even today, when RADAR performance is several orders of magnitude better than in 1944? But there are people in this forum, ASW practitioners, who can tell you better than I could what the introduction of the snorkel meant for the U-Boats.

Didn't say they had NO positive effect - just that it was not as wonderful a solution as some authors seem to have implied.

Running the diesels emitted a rather loud sound signature which attracted attention, and usually there was smoke that could be seen on the surface... from what i've read about semi-current (well, up to the 80s)ASW - a snorkeling diesel is extremely vulnerable, but someone with more ASW experience than just reading might want to comment.

i AM curious how the same engine that was (according to the above) put on the Type IX could recharge a bigger battery in shorter time than the more conventional sub... this actually contradicts what i've read about the XXI...

Were the 6 hours 12 minutes made without moving? (which would seem to be a detriment to survival and would imply around a 12 hour 24 minute if they usual practice of 1/2 output to recharge and 1/2 to propulsion)... or did they have some other trick?