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RE: Ships too Fragile in AE???

Posted: Fri May 15, 2009 3:33 pm
by John Lansford
US destroyers tended to sink after one torpedo hit; look at the battle reports around Guadalcanal.  There are numerous instances of a DD being hit by one torpedo (have no idea how many were 'long lance') and either breaking in half or blowing up.   I'd say more than 80% of the USN destroyers sunk around Guadalcanal sank from one torpedo hit.   While the physical damage radius of a torpedo might be less than half of a ship's length, that doesn't take into account what is being destroyed or flooded by that hit, plus secondary shock damage and loss of watertight integrity in surviving compartments.  A destroyer had little excess flotation or compartmentalization in the first place, so a torpedo strike amidships leaves little left to keep it afloat.

Cruisers, especially treaty cruisers of 10,000 tons or larger, were more resistant to torpedo damage as should be expected, with none sinking from just one hit, although one torpedo hit always did serious damage (bow blown off, significant flooding, etc).  Nearly every USN cruiser sank after two hits, however; while some took more than two before sinking it's likely they would have sunk with just two hits (Helena is the one I'm thinking of, her back was broken after two hits but was hit by a third before sinking).  The Atlanta class was basically a very large destroyer or destroyer leader and was incapable of surviving more than one torpedo hit; Juneau's back was broken by one hit and Atlanta exploded from one or two hits as well.


RE: Ships too Fragile in AE???

Posted: Fri May 15, 2009 10:34 pm
by Charles2222
I agree with you. I don't see how anybody could believe most DD's survive from a torpedo hit, especially from the most destructive of torps.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 6:53 am
by stuman
ORIGINAL: Miller

I'd rather have more fragile ships, as long as the silly WITP uber Betty/Allied 4E bomber hit rates have been drastically reduced!

Actually now that I am learning to play the Japanese, I think the Betty's should be even uberer; the Zero bonus should not end in May '42, maybe more like August '45. The American Carrieres should always be located at Pearl on Dec 7th, without CAP. And I really like the idea of 6 BS being sunk, at a minimum, every time . At least that's a start.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 9:07 am
by spence
Extrapolating anything from one combat report, especially with FOW, is pretty futile. But, I totally understand why everything is scrutinized and why all the questions are asked. You guys only have these results to go on and curiosity and anticipation are very high.

With that said, I always thought that the surprise attacks on December 7th actually were not typical attacks, in that they had several bonuses/penalties applied for the Japanese and Allies that don't apply on other turns (as long as Surprise is on). I don't think that has changed in AE, so I would be particularly cautious about extrapolating from a Dec. 7th surprise attack to make any assumptions about the game.

I can say for sure though that the last replay of the PH attack that I did this morning 2 BBs were lost and more Japanese planes were shot down. My sense is that the median is about 4 BBs lost, but I've seen just about every possible result. I have no idea what the average flak losses at PH are in AE, haven't really tried to keep track of that, though I know others on the team have spent a lot of time over development fine tuning many parts of the design for historical results, including flak losses.

I agree that there should be some results that lie in the tails of the bell of the bell curve. I don't know how port hits, port supply, and airfield hits, and airfield supply hit, and runway hits relate to one another in the code but if they are distinct from one another (one hit can not fall within two categories) then the attack discussed in this thread seems to sit well beyond the edge of any bell: the number of hits exceeds the number of attacking aircraft (including fighters).

Knocking out 5+ airfields completely and sinking or damaging almost 3 times the number of ships that were hit in the original completely successful raid seems a bit too much.

My biggest problem with results such as these is that for the Japanese Player there is no possibility that the biggest gamble the IJN ever took can turn out badly: the only question anybody has is how good it turns out in each instance.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 11:00 am
by herwin
ORIGINAL: Charles_22

I agree with you. I don't see how anybody could believe most DD's survive from a torpedo hit, especially from the most destructive of torps.

It depended on the DD class. Fletcher, Sumner, and Gearing class DDs at 2,000-2.500 tons standard displacement did better when hit by a torpedo than some of the pre-war DDs at 1,400-1,600 tons and a lot better than the 4-stackers at 1,200 tons.

Six RN CLs sank after one underwater hit, as did the Ark Royal. Ten IJN cruisers sank after an engine-room hit.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 11:07 am
by Iridium
ORIGINAL: herwin
Six RN CLs sank after one underwater hit, as did the Ark Royal. Ten IJN cruisers sank after an engine-room hit.

I want to say that most IJN cruisers were getting hit by a lot more than just engine room hits when they did finally get their come-uppins. British ships as a whole were oddly lacking in damage control coordination and backup power. Though one needs power in order to coordinate damage control so if it's lost...

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 11:18 am
by herwin
ORIGINAL: Iridium

ORIGINAL: herwin
Six RN CLs sank after one underwater hit, as did the Ark Royal. Ten IJN cruisers sank after an engine-room hit.

I want to say that most IJN cruisers were getting hit by a lot more than just engine room hits when they did finally get their come-uppins. British ships as a whole were oddly lacking in damage control coordination and backup power. Though one needs power in order to coordinate damage control so if it's lost...

The problems with the RN and IJN ships were design errors, not damage control problems. The Clevelands came close, but the USN was very careful about controlling their topweight.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 11:25 am
by Iridium
ORIGINAL: herwin

The problems with the RN and IJN ships were design errors, not damage control problems. The Clevelands came close, but the USN was very careful about controlling their topweight.

I dunno, when a 40,000 ton ship sinks from one torpedo, no matter how badly designed (unless built with no WTCs), I consider that a damage control issue.


EDIT:

Granted, large fleet vessels should have aux. power (poor design) but one would hope that since this was the fleet you have to work with, you would train your crews to deal with the unique oddities that might come up on these ships.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 11:51 am
by herwin
ORIGINAL: Iridium

ORIGINAL: herwin

The problems with the RN and IJN ships were design errors, not damage control problems. The Clevelands came close, but the USN was very careful about controlling their topweight.

I dunno, when a 40,000 ton ship sinks from one torpedo, no matter how badly designed (unless built with no WTCs), I consider that a damage control issue.

Which 40,000 ton ship? The Ark Royal sunk by one torpedo was a 22,000 ton pre-war CV. The uninterrupted boiler room flat turned out to be more of a design error than was understood at the time by the Board of Inquiry. The Illustrious nearly sank in the same way.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 2:46 pm
by jrcar
Somehow posted to the wrong thread, sorry!

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 3:39 pm
by Puhis
ORIGINAL: herwin

ORIGINAL: Iridium


I dunno, when a 40,000 ton ship sinks from one torpedo, no matter how badly designed (unless built with no WTCs), I consider that a damage control issue.

Which 40,000 ton ship? The Ark Royal sunk by one torpedo was a 22,000 ton pre-war CV. The uninterrupted boiler room flat turned out to be more of a design error than was understood at the time by the Board of Inquiry. The Illustrious nearly sank in the same way.

Maybe Taiho? Fully loaded Taiho was 37,270 tons ship. Only one torpedo and very badly damage control was needed to destroy her.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 5:56 pm
by Charles2222
ORIGINAL: herwin

ORIGINAL: Charles_22

I agree with you. I don't see how anybody could believe most DD's survive from a torpedo hit, especially from the most destructive of torps.

It depended on the DD class. Fletcher, Sumner, and Gearing class DDs at 2,000-2.500 tons standard displacement did better when hit by a torpedo than some of the pre-war DDs at 1,400-1,600 tons and a lot better than the 4-stackers at 1,200 tons.

Six RN CLs sank after one underwater hit, as did the Ark Royal. Ten IJN cruisers sank after an engine-room hit.
Oh yeah, there were some that would come away better off, but then it depends a lot on how clean a shot they got too.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 9:32 pm
by Iridium
ORIGINAL: herwin

Which 40,000 ton ship? The Ark Royal sunk by one torpedo was a 22,000 ton pre-war CV. The uninterrupted boiler room flat turned out to be more of a design error than was understood at the time by the Board of Inquiry. The Illustrious nearly sank in the same way.

Huh, guess my memory is a tad foggy on the tonnage, for some reason I thought Ark Royal was near 40k tons. Upon looking you'd be hard pressed to even suggest it to be 30,000 tons (at full load). Still, DDs I can accept sinking via a single torpedo hit. A vessel 22x (or only 11x if a late war DD) heavier than said DD sinking by the same weapon seems rather odd even with poor design choices.

RE: Ships too Fragile in AE???

Posted: Sat May 16, 2009 10:42 pm
by John Lansford
Kongo sank from one torpedo hit, according to the sub commander that got the hit on her.

Many of the RN CL's were small ships, with less than 10,000 tons displacement.  A ship that small compromises on many design features to squeeze certain demands into the hull, and one of them is watertight compartmentalization.  Areas like magazines and engine rooms must be of a certain size and a hit in these areas seriously threatens flotation as well as mobility or firepower.

RE: Ships too Fragile in AE???

Posted: Sun May 17, 2009 12:06 pm
by tondern

[font="Times New Roman"][/font][font="Times New Roman"]Interesting discussion.

From hazy memory I believe that in D.K. Brown's (most excellent) analysis something like 17 British Destroyers survived single torpedo hits. He concluded that as long as the torpedo didn't break the ship's back, survival was likely. Breaking the back has to do with violent acceleration amidships caused by the explosion - horizontally but especially vertically. The farther the hit was below the waterline, the greater the transmission of explosive force into acceleration.

That means a destroyer taking a deep hit by a big torp anywhere plus or minus a hundred feet of amidships (say 60% of the hull) was likely a goner. With a little dinky 18" air dropped torp (Nells, Bettys, Kates, Jills, etc.) even a hit amidships was probably not always fatal. Hits in the bow or stern are likely non-fatal even with a big torp, and certainly with little (air-dropped) torps. The destroyer losses in the Solomons were the result of very big torpedoes (24"), the existence of which was unknown to Allied intelligence.

So - could a DD sink from a single torp? Yes, easily. Could it survive? Yes. Especially from a single 18" air-dropped torp.

Humbly Yours, Johnny


[/font]

RE: Ships too Fragile in AE???

Posted: Sun May 17, 2009 1:40 pm
by SamRo115
Gentalmen might I prescribe a trip to your local Public house...

RE: Ships too Fragile in AE???

Posted: Sun May 17, 2009 8:18 pm
by Iridium
ORIGINAL: John Lansford

Kongo sank from one torpedo hit, according to the sub commander that got the hit on her.

I meant losing a capital ship to one torpedo is only understandable when it's more than just design flaws, ie. crew inabilities or plain quirky hits/damage inflicted.

RE: Ships too Fragile in AE???

Posted: Mon May 18, 2009 8:02 am
by Dili
I think PoW could have sink just from that torpedo hit in the stern.

RE: Ships too Fragile in AE???

Posted: Mon May 18, 2009 8:39 am
by herwin
ORIGINAL: Iridium
ORIGINAL: John Lansford

Kongo sank from one torpedo hit, according to the sub commander that got the hit on her.

I meant losing a capital ship to one torpedo is only understandable when it's more than just design flaws, ie. crew inabilities or plain quirky hits/damage inflicted.

Tully indicates there were three hits, which is the expected number of hits to sink her given the age of her design.

RE: Ships too Fragile in AE???

Posted: Mon May 18, 2009 9:00 am
by herwin
ORIGINAL: Dili

I think PoW could have sink just from that torpedo hit in the stern.

PoW sank from four or five hits, which is less than the seven expected based on her waterline area and date of design. There's a discussion in Brown. My take is that the design was deficient in similar ways to those of British cruisers and carriers, although not quit as spectacularly bad. Brown admits there were problems of competence in the design office.

By the way, I mentioned that the Illustrious nearly followed the Ark Royal in succumbing to a bad engineering layout. It turns out that the Indomitable had a similar near-miss during the Husky operation. Once is accident; twice is coincidence; and three times is enemy action.