Best Designed Ship of WWII

[Tiornu]

What? No. We can't even do that today.

Send your correction to the Naval Technical Mission to Europe.

[Big B]

Let's see...which WWII ships are still in use(and every conflict since WWII)?
Easy - the Iowa class battleships (Midway class carriers would have been the next choice, but they found replacements for those...after 50 years).

[JWE]

ORIGINAL: Nikademus
suppose. This is interesting. Here's Blair's exact quote for intellectual digestion (alka seltser on the ready)

"Hurriedly prefabricated in 32 different factories that had little or no experience in submarine building, the 8 major hull sections of the Type XXI were crudely made and did not fit together properly. Therefore the pressure hull was weak and not capable of withstanding sea pressure at great depths or the explosions of close depth charges. The Germans reported that in their structural tests the hull failed at a simulated depth of 900 feet. The British reported failure at 800 feet, less than the failure rate of the conventional U-boats."

*****

maybe the key factor was in the "hurriedly" made part. Rush jobs usually breed QA issues.

Misunderstanding I think. I was commenting on mixing/matching. I’m suggesting that nobody had a pile of components and then looked through them, mixing/matching, to find the ones that fit together best. There was a missing (/quote) in the original post. The wasted resources and space would boggle the mind.

Yeah, I fully agree, a demoralized, inexperienced workforce, rushing through fabrication before the bombers come again. It’s no wonder hulls were weak and sections were misaligned. But mixing/matching wouldn’t be any help at all. How many submarine pieces you gonna store in the back lot till you find two that fit together good enough? And what do ya do with the ones that don’t?

I think they had poorly made components and just used what they got as soon as they got them. Yeah, QA issues. Big QA issues.

Probably lot better boats than the test results show, if they could have got their poopie together and done it right from the beginning.

[borner]

Coral sea class. Designed in WWII, in far longer than any other class of the day.

[Hornblower]

What about the Gearings?  some were around till the late 80's

[treespider]

Not a ship...but here is my vote-

[mikemike]

ORIGINAL: Nikademus


This is interesting and provides an interesting contrast to Clay Blair's analysis of the Type XXI. I got the impression that it was a bit on the harsh side (as are many of his viewpoints in his two book series. Here's what he said about the Type XXI's flaws based on a US analysis of the U-2513. (highlights)

1) Poor Structural Integrity

due to hurriedly prefabrication of hull sections from up to 32 different factories that had little experience in building submarines. He claims each section was crudely made and didn't fit well together therefore led to weak pressure hulls.

he cites a German report that simulated tests failed at 900 feet. A British report - 800 feet. I'm guessing the "poor" rating comes from Blair's concluding statement that the 800 foot rating was less than the failure rate of a conventional uboat.

2) Underpowered diesel engines.

Blair says the superchargers of the new model six cylinder diesels were so poorly designed that they could not be used. The alleged failure reduced HP to 1200 leaving the Type XXI underpowered.

3) Impractical Hydraulic system.

(I'll quote this in full given the detailed info you've provided)

The Main lines, accumulators, cylinders, and pistons of the hydraulic gear for operating the diving planes, rudders, torpedo tube outer doors, and anti-aircraft gun turrets on the bridge were too complex and delicate and located "outside the pressure hull." The gear was therefore subject to saltwater leakage, corrosion, and enemy weaponry. It could not be repaired from inside the pressure hull. (obviously.....[:D])

4) Imperfect and Hazardous Snorkel.

This is a long standing Blair jump up and down point. He thinks the device was overblown in it's potential.

specifically, it dunked often, even in moderate seas which in turn caused auto closure of intake exhaust ports. This caused Carbon Monoxide buildup in the pressure hull which led to sickness and ill health effects. (headaches, eye discomfort etc) While closed the diesels would also suck internal air from the boat. He calls using the snorkel on a type XXI a "nightmarish experience" (or in any other U-boat for that matter)

Ironically, in the next paragraph he does admit that the US Navy "did" in fact incorporate "some" of the features of the Type XXI electro boat for it's new sub designs in the immediate postwar years.

I'd be interested in your opinions on Blair's analysis. (Tironu feel free to jump in too) I've always wondered if there were more than a little sour grapes in the above. His viewpoint on Germany's uboat force was very different at the time he wrote Silent Victory.

My comments:

1) Poor Structural Integrity

Essentially true. The Type XXI consisted of eight sections plus the conning tower, whose basic structure was manufactured by steelbuilding companies in the interior, none of whom had shipbuilding experience. They were unable to stay within the originally demanded tolerances, so these had to be downgraded to +/- 2,5 mm in diameter or +/- 5 mm in circumference. However, even when nominally staying within tolerance, nobody seems to have compensated for thermal expansion/contraction. These "raw sections" were delivered to eleven shipyards where they were completed and then transported to the three assembly yards. It was there that mismatches in diameter had to be "fixed". It is safe to assume that the quality of the pressure hull varied between boats depending on how well the sections matched. Sections were built for specific boats but I guess could have been selected for compatibility to a degree; they were exchanged anyway when damaged/destroyed by bombs. I don't think the sections as such were crudely made, the essential welds were made by automatic welding machines and checked by x-raying, and all the companies involved were quite capable of quality welding, the trouble came when assembling the sections to a complete boat.

Concerning the strength of the pressure hull, it was apparently impossible to precisely calculate the strength of the double-bubble hull at the time, so the lower lobe of the hull was more or less designed by educated guess. Model tests in a pressure tank could only be performed in January/February, 1945, and showed that the lower lobe started to deform at 30 atmospheres or about 300 metres of water column (about 985 feet) and failed at 31,5 atm (315 metres or 1030 feet), this was 10% below specification but still better than most other subs at the time. Deep-diving trials with actual boats could only be done off Norway and were performed in April 1945 to a maximum depth of 220 metres/720 feet; they were terminated because pressure-tight containers for inflatable boats under the upper deck imploded. Further tests were prevented by the German capitulation.

2) Underpowered diesel engines.

The diesels were turbocharged. They worked fine when running on the surface, developing 2000 hp/1760 shp, but were so choked by insufficient induction/exhaust line cross-sections when snorkeling that the supercharger was practically ineffective, so the supercharger was not fitted to later boats, reducing output to 1400 hp/1230 shp on the surface and 1200 hp/1030shp when snorkeling. This was quite sufficient to fully recharge the batteries when snorkeling in 6.2 hours. As the boats were expected to operate mainly submerged, surface performance was irrelevant.

3) Impractical Hydraulic system.

This was the first type using hydraulics, earlier boats were mainly electric, but the higher rudder forces at higher underwater speeds could better be handled by hydraulic actuators; in addition, this saved copper. The system was overly complex at first, but was considerably simplified following trials and gave no trouble afterwards. The only essential part outside the pressure hull was the actuating system for the forward dive planes; these were, another first for German subs, retractable, and for simplicity the whole mechanism was copied from the Dutch O25 class. Rudder/Stern planes were actuated by hydraulic rams inside the pressure hull via rods. I respectfully suggest that the system may have seemed "too complex and delicate" to US crews of the time where engineering officers didn't always have engineering backgrounds but may not have posed any particular problems to German engineering staff.

4) Imperfect and Hazardous Snorkel.

The snorkel was an afterthought on the Type XXI and the installation was not optimal, maximum snorkeling speed was six knots as the snorkel started to vibrate strongly at higher speeds, not being streamlined. The system was designed to suck air from the interior of the boat when the snorkel was dunked, that was what made it practicable as otherwise the engines would either have aspirated water or come to an immediate stop. Exhaust ports were never closed when snorkeling. Exhaust gas leakage was a problem on older boats retrofitted with snorkels, but the Type XXIs had an exhaust system designed with snorkeling in mind and had air conditioning anyway. Maybe the system was imperfect but it was better than the USN system, which was nonexistent, or anybody else's, for that matter.

There was a marked tendency immediately postwar for US analysts to declare that nothing of value could be learned from German or Japanese equipment which was patently untrue in many aspects. Probably a case of "Not Invented Here".

(This led, amongst other consequences, to a scrapping of most captured enemy equipment. The USA had three or four specimens of every aircraft type that reached combat status in the Axis countries, and a number of prototypes in addition, and there are hardly any original aircraft left today.)

[Nikademus]

ORIGINAL: Tiornu

Radar bearing data was inferior to optical bearing data.

Concur.

[Nikademus]

Thx MM.

Very interesting!

[mikemike]

ORIGINAL: JWE

Yeah, I fully agree, a demoralized, inexperienced workforce, rushing through fabrication before the bombers come again. It’s no wonder hulls were weak and sections were misaligned. But mixing/matching wouldn’t be any help at all. How many submarine pieces you gonna store in the back lot till you find two that fit together good enough? And what do ya do with the ones that don’t?

I think they had poorly made components and just used what they got as soon as they got them. Yeah, QA issues. Big QA issues.

Probably lot better boats than the test results show, if they could have got their poopie together and done it right from the beginning.

This is a bit overstated. The workforce was experienced enough, but low on body count, which slowed construction. They may have been demoralized, but I imagine the Gestapo may have compensated for that. The air threat was considerable, of course, that is why much of the section work was shifted to bunkers. Most section yards escaped being targeted for bombing, anyway, because they had nothing showing on the slips anymore. An interesting detail in this context is that, when sections were assembled, this was done by four welders simultaneously, evenly distributed around the circumference of the hull, and that the welding process was not to be interrupted for any reason, even under air attack.

Sections were, as I've said, designated for specific boats from the start. There wasn't normally any mixing/matching, except when sections were destroyed by bombing.

I also don't believe in poorly-made components on a large scale. The section yards were responsible for delivering only sections that were up to specifications, meaning they had to do extra remedial work when supplied with substandard components or the section wouldn't have been accepted by the relevant team of the War Production Ministry.

Sections were not misaligned as such on assembly, proper (longitudinal) alignment was very carefully checked by optical measuring methods. However, if the diameters of the sections differed too much, the methods used to adapt the sections to each other might well have weakened the structure.

I agree that the Type XXI program would have progressed smoother and faster if the section yards had built the whole section by themselves, but the planning called for building rates that couldn't have been achieved in that way, so some subassembly was farmed out to subcontractors. This is still a risk even today, witness the Boeing 787 troubles.

[borner]

another for the effectiveness in combat has to the the Gato class fleet boat. for the time, a great SS design

[DuckofTindalos]

ORIGINAL: Nikademus

suppose. This is interesting. Here's Blair's exact quote for intellectual digestion (alka seltser on the ready)

"Hurriedly prefabricated in 32 different factories that had little or no experience in submarine building, the 8 major hull sections of the Type XXI were crudely made and did not fit together properly. Therefore the pressure hull was weak and not capable of withstanding sea pressure at great depths or the explosions of close depth charges. The Germans reported that in their structural tests the hull failed at a simulated depth of 900 feet. The British reported failure at 800 feet, less than the failure rate of the conventional U-boats."

*****

maybe the key factor was in the "hurriedly" made part. Rush jobs usually breed QA issues.

Even more so when it's rush jobs by concentration camp inmates.

[juliet7bravo]

Still a Gato/Balao in active service, Taiwan I think...

[vettim89]

This thread is intrigueing. Amazing how many forum members have such in depth knowledge or naval architecture. I am a history buff and probably know more about a/c design than ship design. Still I would like to make some comments. The name of the thread is "Best Designed Ship of WWII" not "Best Ship of WWII". As such the criteria should, in theory, be a little different. Some things to consider:

1. Did the design meet the need for which it was intended?
2. Was the design able to be brought to the front in time to make a difference for the side involved?
3. Was the design feasible? (Were the resources, slips, manpower, technology, etc there to build the ship)?
4. Did the design bring the concept for that class forward? (i.e., did others look at it and try to emulate it?)
5. Possibly a special mention for designs that converted existing hulls to other purposes and were successful
6. Was the design effective?
7. Was the design still relevant by the time the ships entered service
8. Did the design have any flaws that seriously affected performance?

I bring up these points because, in my mind, some of the ships mentioned as candidates fail in one or more of the categories. Just some examples by item number above:

1. Alaska class BC/CA
2. Midway class CV
3. Can't come up with an example but some of the late war Japanese designs fall here
4. Bismark (not measuring the quality of the ship but she was undergunned compared to her contempories)
5. Opposite here (ships that should be considered): CVL Independence, CVE's
6. Most ships mentioned meet this criteria or they wouldn't be mentioned
7. BB Yamato, BB Iowa, etc. Nice ships but wrong war
8. CV Yorktown class - I have read that these ships had poor engineering space planing and were vulnerable, Also, CL Brooklyn and Cleveland classes both were notoriously bad in heavy seas and had weight issues

A ship that I am surprised more people haven't made a case for is CA Takao class (arguably the best Treaty Cruisers of any combatant). My nominees would be CV Essex, Liberty/Victory ships, DD Gearing, SS Gato, CA Takao, and probably the Type XXI SS. JOMHO

So on these criteria I would

[Tiornu]

I’m suggesting that nobody had a pile of components and then looked through them, mixing/matching, to find the ones that fit together best.

Yes, I think you must be right in that no one was going over rivets with a magnifying glass. However, there were problems matching the hull sections. If this is of sufficient interest, I can try to find a direct quote.

[Dili]

By 1944, splash and splash size (could differentiate between 8" and 16" and 5") were detectable. US fire control also provided perfect range (distance solution), better azimuth than optical control, and better solutions on a target vessel's course and speed than optical control. US optical directors were more or less there to backstop the radar solutions in the event of electronic wierdness or failure.

The difference between radar and optical was light years of quality. As long as the set was working (which in the US was "pretty much always" after 1943), a US ship could maintain a constant range, bearing and speed solution on a target even as the US ship maneuvered radically to avoid incoming rounds. With optical control you could choose between reasonably decent solutions (although not as good as radar) on the target or radical maneuvering to avoid incoming rounds, but you could not have both.

That's why I think Yamato was doomed. I might have said "if the US radar set was working" but after the trouble with SoDak in 1942, the emphasis on keeping your electronics working took on a whole new priority in the USN. To have a prayer, Yamato would have to catch a US BB entirely by surprise and at close range, or else it'd have to steer a very straight, predictable, and cumbersome course and speed just to try to maintain a solution on a US ship. And the Yamato would have been a very easy, relatively soft target for a USN 16" rifle.

Really, all Yamato had going for it was displacement. As did all BBs. Yamato, Bismarck, Musashi, Prince of Wales, all took a substantial pounding primarily because there was alot of space that had to be flooded in order to put the beasties underwater.

Thanks, but your hyperbolic language don't help at all to convince me like the use of "perfect". I just need to look at precision values in a Search Radar of 70's 80's to see the issues at long range. Btw could a 1944 fire control get constant feed of radar data and what was actualization rate?

Also are there any real examples of long range gunnery by US ships against other ships in 43,44,45?

[Dili]

CA Takao class

Why Takao is better than Mogamis? The Japanese would have made the next cruisers as Mogami Plus. I also have some dificulties to rate Japanese Cruisers as Treaty Cruisers when they outrageously violated it even then with 25mm armor in turrets and spent a big amount of rounds to hit a merchant.

[rjopel]

Didn't the USS Boise drive back a German tank assault on the Sicily invasion beaches from a pretty good distance?

[Nikademus]

ORIGINAL: Tiornu

I’m suggesting that nobody had a pile of components and then looked through them, mixing/matching, to find the ones that fit together best.

Yes, I think you must be right in that no one was going over rivets with a magnifying glass. However, there were problems matching the hull sections. If this is of sufficient interest, I can try to find a direct quote.

I'm still curious about the why behind the hydraulics placement. Is there any info regarding this?

[Dili]

Yes Italians first and then Germans and it included DD fire also it is not the same as firng in a moving ship. i have to search Morrison but it think they were only a couple of miles from Coast. Not long range.

Here is a discussion about the not glowing results of BB fire against Coastal Guns which as everybody knows it is a fixed target.

http://www.worldaffairsboard.com/battle ... check.html

In short my conclusion is that at long range, the perennial luck still have a big saying in clear daytime, Radar or no Radar.