Scharnhorst vs Alaska

[Kurfürst]

So you dont think the ability to place a an 1140 lb shell, capable at that range (18000 m) with armour penetration of about 14 inches is going to hurt the German Battlecruiser.

He is right - 14 inches is way insufficient to get some real hurt to the Scharnhorst class - deck arrangements being such as they were, quite similar to the Bismarck - all it can do is to mess up the non-vital areas above the armored deck. Nothing that would compromise the ship's fighting capacity is there, however.

By comparison the the German ship can penetrate about 8.8 inches of plate, which is not quite enough to penetrate the main belt of the Alaska, once the angle of the hit is taken into account, as well as the STS bulkheads on which the Alaskas belt is hung

I think you should check the gunnery tables again.

I did check the gunnery tables, and your comparison of the two guns is questionable... appearantly you took the figures for the US 12" gun calculated using the USN's empirical formula, which generally produces higher penetration figures for all projectiles, and compared that the Krupp live fire test results using a pre-war propellant, fired at a plate with an impact angle of 70 degrees... tsk-tsk-tsk! 8)

In reality, using similiar, comparable figures we get, at 20 000 yards, using in both case the USN Empirical Formula for Armor Penetration.

28 cm/54.5 (11") SK C/34 11.47" (291 mm) 1.87" (48 mm)
12"/50 (30.5 cm) Mark 8 : 12.73" (323 mm) 3.02" (77 mm)

The difference in figures for belt penetration are marginal using the same conditions, and more pronounced in deck penetration.

However, whereas the Alaska's 12" guns must go through a 350 mm belt and thereafter attempt the impossbile, penetrate a high sloped 105 mm deck - even far larger gun calibres didn't have the power for that. OTOH the 28cm guns on the Scharnhorst only have to go through a single 9"/228mm thick belt before the the vitals can be reached.

This is quite easily possible, for as per the USN formula the 28cm gun can still penetrate a 8.08" (205 mm) belt at 30 000 yards (so a 9 incher is probably vulnerable at 27-28k).

At 18000 metres the Alaska could use her 5 inche guns with a firing cysle on average threee time the rate of the 5.9 inch guns on Scharnhorst.

To what purpose..? The 5" guns cannot possibly do but superficial damage to the Scharnhorst superstructure or exposed systems like radar etc. They cannot do any harm at all inside the citadel (70% of the ship hull...) due to the rather thick upper side belt and top armored deck - these are impossible to penetrated by 5" using any type of round at most practical ranges (the upper belt becomes vulnerable at sub-10 000 yard ranges).

Not to mention, comparing the secondaries we speak of 12 x 5" guns on one ship, incapable of giving hurt to the other ship vs. the 12 x 5'9" and 14 x 4.1" guns (the latter which you ignored) on the Scharnhorst. The firepower of the secondaries on the Scharnhorst is quite simply much superior, especially coupled with that Alaska's armor is far less extensive than the Scharnhorst, and most of the upper works is vulnerable for both 4.1" and 5.9" guns.

 

[parsifal]

So what is the belt defences of the Scharnhorst. Conways has it listed as 6.75 inches through to 13.75 inches. There was an armoured deck of 3inches, main deck of 2inches, sloped to 4 inches. I dont follow why it is impossible to penetrate this with a weapon able to penetrate 15.5 inches at 15000 yards

Its intersting that you and DONL both claim that the 12/50 with the new AP-18 1140 lb charge with an MV of 2500fps cannot penetrate the main belt of the Scharnhorst. As I said, at that range, with the new round it can penetrate 15.56 inches of armour plate.

By comparison, the 14/45 fitted to the british Duke of York could penetrate 13.2 inches of stell at that range. And this gun was able to penetrate and severeely damage the Scharnhorst out to 24000 yds....

You also omit that the Alaska has a 0.625 STS belt behind the 9 inch main belt and than a 4 in sloped armoured deck designed to protect its vital areas in a similar armoured box manner as the Scharnhorst, as well as a further 1.4 inch main deck as well.

Alaska is not as well protected as Scharnhorst, particularly in her below the waterline arrangements and in her internal subdivision. However, she possessed an immune zone against the 12 in 1140 lb shell of 18-24000 yards so I am not exaggerating when I say it was also designed to resist the effects of the weaker 28cm weapon at hose ranges as well.

To support the notion that Alaska was designed to withstand fire from ships like the Scharnhorst, I direct you to an article by Chuck Hawks, who is a prolific and competent historian having written extensively on many aspect of naval warfare

Here is the link if you are interested in learning something

http://www.chuckhawks.com/battlecruisers.htm


Relevantly the article make these comments rehgarding this issue...

"The 12in guns were a new design; they could penetrate 15in of belt armor at 16,000yds, and 5.5in of deck armor at 30,000yds. This made them effective against all battlecruisers and many battleships. They fired a new, super heavy AP shell weighing 1,140 lbs. Note that the French 13in gun fired an AP shell only slightly heavier at 1200 lbs, and the German 11in AP shell weighed just 700 lbs. The previous American 12in shell weighed 870 lbs. Not only did the new American AP shells have great sectional density, which means that they were heavy for their diameter, they were also much more effective and reliable in use than the German or Japanese AP shells. The secondary and AA battery of the Alaskas was superior to their rivals, both in number of guns, and in performance of the individual guns themselves. By the time the Alaskas entered service, American radar fire control was superior to anything the Axis powers had. This advantage would be particularly apparent at night or in inclement weather.

These ships did not carry torpedoes. This is in line with the U.S. Navy policy of not equipping battleships and cruisers with torpedoes. While heavy and light cruisers can and did benefit from carrying torpedoes in WW II, they are a detriment on capital ships. Not equipping the Alaskas with torpedoes was the correct decision. Not having the dangerous things on deck would have been an advantage had the Alaska met either the German P class or the Japanese B 64 class in battle.

The Alaska class was generally well protected compared to the Axis battlecruisers. At it's most favorable point, their armor was adequate to defeat their own 12in AP shells between 18,000 and 24,000yds. Against 8in cruiser fire, their immune zone was 9,500-29,200yds, and against the German 11in AP shell it was approximately 16,600-27,800yds. They would have been quite vulnerable to the 14in AP shells of the Kongo or B 65 type, or the 15in AP shells of the P class, but those ships would also have been quite vulnerable to the Alaska's super heavy 12in AP shells (see below).

It is interesting to play "what if". Comparing the Alaska to the Axis battlecruisers she might have met, I think she would have done well against most of them.

American AP shells work better than German AP shells...And as good as German optical fire control is, American radar control is even better. And Alaska doesn't carry any torpedoes to sink merchant ships, so the nasty things can't explode and tear her stern off, or worse. Again, it would probably come down to who gets the first lucky hits, but I'm betting that might just be Alaska. Its ironic to consider that the ships the U.S. Navy refused to admit were battlecruisers, might well have been the best battlecruisers of their generation!"


Chuck does think that the Scharnhorst may well overpower the Alaska, and I have never said this was not entirely possible, but he does corroborate all that I have been saying...namely that radar assisted fire control was far superior to optical, that the new US 12" gun and its new round were extremely powerful, and that the armouring scheme of the Alaskas was sufficient for her to reduce the range to 18000 yards with a fair degree of safety.....fighting the Scharnhorst would be hard, but I think the odds remain in her favour just the same


Tsk Tsk indeed

 

[Vincenzo]

Parsifal we need noted that the new british 14'' has heaviest projectile and near same MV of new US 12''. and the table on naval weapons page for 14'' it's for average gun (so lowest MV) and for 12" it's for new gun the tables are not build with 100% same method.

p.s. on Hawks article not all it's true

 

[parsifal]

Parsifal we need noted that the new british 14'' has heaviest projectile and near same MV of new US 12''. and the table on naval weapons page for 14'' it's for average gun (so lowest MV) and for 12" it's for new gun the tables are not build with 100% same method.

p.s. on Hawks article not all it's true

Hi Vincenzo

AFAIK the Alaska used the MK 18 shell (ie the 1140 lb version) throughout its operational carreer. In any event the issue being asserted is not what shell is being used or was used by the Alaska, but specifically that the MK-18 "supershell" could not overpower the defensive scheme of the German ship. Clearly avery reputable reference on this round suggests otherwise, but lets not let the truth get in the way of a cherished myth.....

I know that the british shell is the "standard" shell, but nevertheless this standard shell was able to fairly easily overpower the defensive scheme of the Scharnhorst......so why can a gun and a shell with an even higher rating not do that as well?

What bits of the extract I produced do you think are not true......do I just have to accept your say so, or do you have some alternative sources??? What specifically dont you believe, so that we can examine the evidence and achieve a better understanding of the problem...

 

[Kurfürst]

Hi Vincenzo

AFAIK the Alaska used the MK 18 shell (ie the 1140 lb version) throughout its operational carreer. In any event the issue being asserted is not what shell is being used or was used by the Alaska, but specifically that the MK-18 "supershell" could not overpower the defensive scheme of the German ship. Clearly avery reputable reference on this round suggests otherwise, but lets not let the truth get in the way of a cherished myth.....

Well the only one creating myths around here is you as well as using strawmen arguements. It was quite clearly stated that the 12" shell, for that matter, far more powerful shells are completely incapable of hurting the combination of 350 mm KC n/A plus a backing slope of 105 mm Wh. Nathan Okun did a lenghty analysis of Bismarck's protection scheme (which was 320 mm Kc n/A with 110 mm slope of Wh), the conclusion which I am fairly certain you are aware of was that even the Yamato's 18,1" guns would be needed to put right next to main belt (range=0 yards) to have even a chance to go through both plates and reach the vitals intact, as stated by Okun.

The Alaska class's armor armor composition was quite different, as usual a single moderately thick - compared to US BBs - armored deck upon the top of the side belt, on the scale of that of Scharnhorst, but had no slope backing up the main belt as on the Scharnhorst.

You changed that to an absolute, that could not overpower the defensive scheme of the German ship - nobody said that. Certainly it was possible to overpower it, especially against the deck, if the range was long enough, ca 23-25 000 yards or greater. The main belt was another matter, as explained above.

 

[Kurfürst]

So what is the belt defences of the Scharnhorst. Conways has it listed as 6.75 inches through to 13.75 inches. There was an armoured deck of 3inches, main deck of 2inches, sloped to 4 inches. I dont follow why it is impossible to penetrate this with a weapon able to penetrate 15.5 inches at 15000 yards

Simply because both the main belt and the slopes on the two sides are at the level at the waterline, ie. every projectile that wants to touch the vitals has to pass through the ca 105mm slope or the 80mm deck amidships, at an extremely unfavourable shallow angle, after penetrating the main belt itself.. it simply ain't gonna happen.

Its intersting that you and DONL both claim that the 12/50 with the new AP-18 1140 lb charge with an MV of 2500fps cannot penetrate the main belt of the Scharnhorst. As I said, at that range, with the new round it can penetrate 15.56 inches of armour plate.

Of course it can penetrate the main belt. Problem is, in order to reach into the vitals, the much slowed down projectile, stripped of its AP cap, would also have penetrate the 80mm deck/105mm slope that is still between it and the machinery or magazines, and that at an extremely unfavorable angle. Ain't gonna happen - not even if you place the guns directly against the belt. Sure they will penetrate the belt itself, and then richochet off upwards from the main deck and the slope, doing only non-critical damage in the process.

The only way is if the projectile goes through the upper side belt, only 50 mm thick, and still have a steep enough fall and enough momentum to still go through the main deck. And that's a pretty narrow window - but possibly enough to make a lucky hit on Scharnhorst by the DoY, and also prompted German designers to beef up this upper belt to 145 mm on the Bismarcks..

You also omit that the Alaska has a 0.625 STS belt behind the 9 inch main belt and than a 4 in sloped armoured deck designed to protect its vital areas in a similar armoured box manner as the Scharnhorst, as well as a further 1.4 inch main deck as well.

There was nothing comparable - Alaska's deck wasn't sloped, nor was it positioned behind the main belt, as was on Scharnhorst and Bismarck.

Alaska is not as well protected as Scharnhorst, particularly in her below the waterline arrangements and in her internal subdivision. However, she possessed an immune zone against the 12 in 1140 lb shell of 18-24000 yards so I am not exaggerating when I say it was also designed to resist the effects of the weaker 28cm weapon at hose ranges as well.

The Alaska's never had such level of protection. See Garzke and Dullin:

To support the notion that Alaska was designed to withstand fire from ships like the Scharnhorst, I direct you to an article by Chuck Hawks, who is a prolific and competent historian having written extensively on many aspect of naval warfare

Err, its an amateur enthusiast's site.. and his opinion agrees with yours? Well, good for you both. 8)

 

[DonL]

Sorry parsifal,

you are talking about myth but you don't read posts from other members exactly.
Your last two posts are wrong, very wrong.

One last description fom me with a lot examples.

The first thing we have talked about a range 18000m or less. Up from 18000m SH ist vulnerable to the guns of Alaska because of her weak upperbelt! Read the post 3 of this thread!

I know that the british shell is the "standard" shell, but nevertheless this standard shell was able to fairly easily overpower the defensive scheme of the Scharnhorst......so why can a gun and a shell with an even higher rating not do that as well?

This is totally wrong! Alaska has no shell thats higher rated than the british shell. The only thing for "super shell" ist the heavy weight of this 12in shell nothing more nothing less.

The british 14"/45 (35.6 cm) Mark VII shoot a 1,590 lbs. (721 kg) shell with 2,483 fps (757 mps), the american 12"/50 (30.5 cm) Mark 8 shoot a 1,140 lbs. (517.093 kg) shell with 2,500 fps (762 mps) and the german 28 cm/54.5 (11") SK C/34 shoot a 727.5 lbs. (330 kg) shell with 2,920 fps (890 mps).

Penetrationpower is not only shell weight but shell weight + Muzzle Velocity
So the Mark 8 is inferior from penetrationpower to the Mark VII. On the other side is the german 11 inch a very good belt penetrator for an 11 in gun because of her very high muzzle velocity but thats also the reason for her poor deck penetration. That are facts parsifal no myths and there is no 12in super shell from the americans only a very heavy shell wth a low muzzle velocity.

Armored Shemes.
SH has the best vertical protection from 18000m less of all Batlleships accept Yamato because of her 170m long and 350mm thick main belt and the 105mm thick low main deck. SH and all other german designs have no amored box like all other designs. This very good vertical protection is only functioning less than 18000m because of the angle of fall from the shells. Up from 18000m the shell can penetrate the upper belt.

Alaska has a high main deck on the main belt of 229mm inclined. So a shell from 18000m or less can penetrate the main belt and goes under the main deck through the ship.
And this is the difference to SH because a shell that penetrates the main belt must also go through the low main deck and the torpedo bulkhead to go through the ship!

In reality, using similiar, comparable figures we get, at 20 000 yards, using in both case the USN Empirical Formula for Armor Penetration.

28 cm/54.5 (11") SK C/34 11.47" (291 mm) 1.87" (48 mm)
12"/50 (30.5 cm) Mark 8 : 12.73" (323 mm) 3.02" (77 mm)

This are the facts from navy weapons parsifal no myths. Or do you think the data of the Mark8 are not true?
This data are with the 1,140 lbs. (517.093 kg) shell with 2,500 fps (762 mps).

I know that the british shell is the "standard" shell, but nevertheless this standard shell was able to fairly easily overpower the defensive scheme of the Scharnhorst

This was up from 18000m or her turrets and there is no secret that the turrets of SH were a weak point.

So this discussion was for the range 18000m or less!

 

[Vincenzo]

Hi Vincenzo

AFAIK the Alaska used the MK 18 shell (ie the 1140 lb version) throughout its operational carreer. In any event the issue being asserted is not what shell is being used or was used by the Alaska, but specifically that the MK-18 "supershell" could not overpower the defensive scheme of the German ship. Clearly avery reputable reference on this round suggests otherwise, but lets not let the truth get in the way of a cherished myth.....

I know that the british shell is the "standard" shell, but nevertheless this standard shell was able to fairly easily overpower the defensive scheme of the Scharnhorst......so why can a gun and a shell with an even higher rating not do that as well?

What bits of the extract I produced do you think are not true......do I just have to accept your say so, or do you have some alternative sources??? What specifically dont you believe, so that we can examine the evidence and achieve a better understanding of the problem...

US new 12" 1140 lbs 2500 fps (new gun)
UK new 14" 1590 lbs 2483 fps (new gun) 2400 mps (average gun)

easy think that a same condition the british it's best.

for true i write in the article but for the extract:
the penetration data for 12" are a bit best of naval weapons table but maybe right.
330 weight it's 1235 (it's right only slightly heavier at 1200 lbs but why not writing only slightly heavier at 1100 for 12"?)
280 weight it's 727
the new 12" it's longest so it's heaviest
why writing axis BC? when for him the only axis true BC are the Kongo (the other are german pocket BB)
i've not armour scheme of Alaska but theyr belt give little protection vs own guns only at so long distance that the distance it's a best protection. the belt has near same trouble vs the german 280.
best battlecruiser of their generation sure there aren't other BC in their generation and they are BC only for some people. (BC need fastest of BB the Alaska aren't fastest of Iowa)

 

[parsifal]

Well the only one creating myths around here is you as well as using strawmen arguements. It was quite clearly stated that the 12" shell, for that matter, far more powerful shells are completely incapable of hurting the combination of 350 mm KC n/A plus a backing slope of 105 mm Wh. Nathan Okun did a lenghty analysis of Bismarck's protection scheme (which was 320 mm Kc n/A with 110 mm slope of Wh), the conclusion which I am fairly certain you are aware of was that even the Yamato's 18,1" guns would be needed to put right next to main belt (range=0 yards) to have even a chance to go through both plates and reach the vitals intact, as stated by Okun.

The Alaska class's armor armor composition was quite different, as usual a single moderately thick - compared to US BBs - armored deck upon the top of the side belt, on the scale of that of Scharnhorst, but had no slope backing up the main belt as on the Scharnhorst.

You changed that to an absolute, that could not overpower the defensive scheme of the German ship - nobody said that. Certainly it was possible to overpower it, especially against the deck, if the range was long enough, ca 23-25 000 yards or greater. The main belt was another matter, as explained above.

These are the facts Kurfurst, which even you cannot deny. The Scharnhorsts defensive scheme was defeated by the 14/45 guns of the DOY, including the turrets of the German ship. I dont really care if the main belt was penetrated or not....I happen to think it was penetrated, you obviously think otherwise....all i know is that a shell of lesser power than the 12/50 was able to defeat the Scharnhorst defences, relatively easily. You and any body else can argue all day about the alleged invincibility of these armouring schemes, but in the cold hard light of day the armouring schemes of these ships were not enough to save them. If the Scharnhorst could not withstand the effects of the 14/45 at those ranges, it would not have been able to withstand the effects of the 12/50, with the heavier shell and superior AP capabilities. This is because the 12/50 with Mark 18 shell was superior in AP qualities to the guns actually used to sink the Scharnhorst

And for the record, Bismarck was silenced very quickly in her last battle, taking less than an hour to be silenced. Though her hull was well protected, her combat capability was knocked out with relative ease in her last fight. So much for the uber defences of the German Battleships.......

These also are the facts...at 18000 yards, the 12/50 with Mk 18 shell can penetrate about 14 inches of armour plate. Thats enough to penetrate your 350 mm main belt. At that same range the 28cm weapon can penetratre about 8.8 inches of plate, which is not quite enough to assure penetration of the main belt. This is exactly the same situation as the Bismarck....the British BBs had enough power to get to the vitals of the ship, though not the citadel. It was enough to knock the ship out easily and quickly. And there is no reason to suggest that the the higher powered 12 inch round would not have the samer effect.

 

[Vincenzo]

Parsifal the british 14" have not lesser poweer of US 12"

p.s.
and after penetred the 350mm deck you need penetred the 80mm deck in lucky hypotesis.
the hit from the deck are the dangeur.

 

[DonL]

These are the facts Kurfurst, which even you cannot deny. The Scharnhorsts defensive scheme was defeated by the 14/45 guns of the DOY, including the turrets of the German ship. I dont really care if the main belt was penetrated or not....I happen to think it was penetrated, you obviously think otherwise....all i know is that a shell of lesser power than the 12/50 was able to defeat the Scharnhorst defences, relatively easily. You and any body else can argue all day about the alleged invincibility of these armouring schemes, but in the cold hard light of day the armouring schemes of these ships were not enough to save them. If the Scharnhorst could not withstand the effects of the 14/45 at those ranges, it would not have been able to withstand the effects of the 12/50, with the heavier shell and superior AP capabilities. This is because the 12/50 with Mark 18 shell was superior in AP qualities to the guns actually used to sink the Scharnhorst

And for the record, Bismarck was silenced very quickly in her last battle, taking less than an hour to be silenced. Though her hull was well protected, her combat capability was knocked out with relative ease in her last fight. So much for the uber defences of the German Battleships.......

These also are the facts...at 18000 yards, the 12/50 with Mk 18 shell can penetrate about 14 inches of armour plate. Thats enough to penetrate your 350 mm main belt. At that same range the 28cm weapon can penetratre about 8.8 inches of plate, which is not quite enough to assure penetration of the main belt. This is exactly the same situation as the Bismarck....the British BBs had enough power to get to the vitals of the ship, though not the citadel. It was enough to knock the ship out easily and quickly. And there is no reason to suggest that the the higher powered 12 inch round would not have the samer effect.

Whats this parsifal? Do you want to provoke?
You are talking nonsens in this post.

 

[parsifal]

you are talking about myth but you don't read posts from other members exactly.
Your last two posts are wrong, very wrong.

One last description fom me with a lot examples.

The first thing we have talked about a range 18000m or less. Up from 18000m SH ist vulnerable to the guns of Alaska because of her weak upperbelt! Read the post 3 of this thread!
Sorry DONL

Your post is somewhat unintelligible to me, but essentially my point is this, the US 12/50 has the ability to disable the Scharnhorst in exactly the same way as the 14/45 did. Dont really care if the belt could be penetrated or not....though I cant see how it is possible to knock the ship out without it....this is because the 12/50 has superior performance to the of the latter gun notwithstanding your rebuttal below

Sorry if I missed post 3, but the the point here is if the Alaska has the power to overpower the Scharnhorst. According to the Nav weapons site her guns do have that capability

This is totally wrong! Alaska has no shell thats higher rated than the british shell. The only thing for "super shell" ist the heavy weight of this 12in shell nothing more nothing less.

The british 14"/45 (35.6 cm) Mark VII shoot a 1,590 lbs. (721 kg) shell with 2,483 fps (757 mps), the american 12"/50 (30.5 cm) Mark 8 shoot a 1,140 lbs. (517.093 kg) shell with 2,500 fps (762 mps) and the german 28 cm/54.5 (11") SK C/34 shoot a 727.5 lbs. (330 kg) shell with 2,920 fps (890 mps).

Penetrationpower is not only shell weight but shell weight + Muzzle Velocity
So the Mark 8 is inferior from penetrationpower to the Mark VII. On the other side is the german 11 inch a very good belt penetrator for an 11 in gun because of her very high muzzle velocity but thats also the reason for her poor deck penetration. That are facts parsifal no myths and there is no 12in super shell from the americans only a very heavy shell wth a low muzzle velocity.

These are the extracts from the Nav weapons site regarding the respective guns

Firstly the skc/34

Armor Penetration with 727.5 lbs. (330 kg) APC L4,4 Shell
.
Range Side Armor Deck Armor
0 yards (0 m) 23.79" (604 mm) ---
8,640 yards (7,900 m) 18.09" (460 mm) 0.76" (19 mm)
16,514 yards (15,100 m) 13.18" (335 mm) 1.63" (41 mm)
20,013 yards (18,288 m) 11.47" (291 mm) 1.87" (48 mm)
30,000 yards (27,432 m) 8.08" (205 mm) 2.99" (76 mm)
Note: The above information is from "Battleships: Axis and Neutral Battleships in World War Two" for a muzzle velocity of 2,920 fps (890 mps) and is based upon the USN Empirical Formula for Armor Penetration.
.
Range Side Armor Deck Armor
10,936 yards (10,000 m) 13.70" (348 mm) ---
16,404 yards (15,000 m) 11.02" (280 mm) ---
21,872 yards (20,000 m) 8.86" (225 mm) ---
27,340 yards (25,000 m) 7.64" (194 mm)

Next the 12/50

Armor Penetration using 1,140 lbs. (517.093 kg) AP Mark 18 Shell
.
Range Side Armor Deck Armor Striking Velocity Angle of Fall
0 yards (0 m) 24.48" (622 mm) --- 2,500 fps (762 mps) 0.0
5,000 yards (4,572 m) 21.34" (542 mm) 0.51" (13 mm) 2,215 fps (675 mps) 2.6
10,000 yards (9,144 m) 18.23" (463 mm) 1.26" (32 mm) 1,948 fps (594 mps) 6.0
15,000 yards (13,716 m) 15.56" (395 mm) 2.14" (54 mm) 1,745 fps (532 mps) 11.0
20,000 yards (18,288 m) 12.73" (323 mm) 3.02" (77 mm) 1,550 fps (472 mps) 17.5
25,000 yards (22,860 m) 10.52" (267 mm) 4.02" (102 mm) 1,435 fps (437 mps) 25.3
30,000 yards (27,432 m) 9.08" (231 mm) 5.11" (130 mm) 1,400 fps (427 mps) 32.8
35,000 yards (32,004 m) 7.35" (187 mm) 7.18" (182 mm) 1,427 fps (437 mps) 44.5
Note: The above information is from "Battleships: United States Battleships 1935-1992" by Garzke and Dulin and is based upon the USN Empirical Formula for Armor Penetration. These values are in substantial agreement with armor penetration curves published in 1942.

Finally the 14/45

Armor Penetration with 1,590 lbs. (721 kg) AP Shell
.
Range Side Armor Deck Armor
0 yards (0 m) 26.9" (668 mm) ---
10,000 yards (9,144 m) 15.6" (396 mm) 1.15" (29 mm)
15,000 yards (13,716 m) 13.2" (335 mm) 1.95" (50 mm)
20,000 yards (18,288 m) 11.2" (285 mm) 2.85" (73 mm)
25,000 yards (22,860 m) 9.5" (241 mm) 4.00" (102 mm)
28,000 yards (25,603 m) --- 4.75" (121 mm)
Note: This data is from "Battleships: Allied Battleships in World War II" for a muzzle velocity of 2,400 fps (732 mps) and is partly based upon the USN Empirical Formula for Armor Penetration and partly based upon official data.

Armor Penetration with 1,590 lbs. (721 kg) AP Shell
.
Range Side Armor Deck Armor
13,700 yards (12,530 m) 14.0" (356 mm) ---
15,800 yards (14,450 m) 13.0" (330 mm) ---
18,000 yards (16,460 m) 12.0" (305 mm) ---
20,000 yards (18,290 m) --- 2.0" (52 mm)
20,500 yards (18,750 m) 11.0" (279 mm) ---
23,700 yards (21,670 m) 10.0" (254 mm) ---
24,000 yards (21,950 m) --- 3.0" (76 mm)
28,000 yards (25,600 m) --- 4.0" (102 mm)
32,000 yards (29,260 m) --- 5.0" (127 mm)
Note: This data is from "British Battleships of World War Two." This table assumes 90 degree inclination and is based upon theoretical calculations performed in 1935, not actual firing trials.

As can be seen, according to this site, the 12/50 has superior AP capability over the 14/45. Nothing I can do to contradict that from the US point of view it has superior performance to the standard 870 lb shell originally designed for the gun. Never said they were super shells, just superior

Armored Shemes.
SH has the best vertical protection from 18000m less of all Batlleships accept Yamato because of her 170m long and 350mm thick main belt and the 105mm thick low main deck. SH and all other german designs have no amored box like all other designs. This very good vertical protection is only functioning less than 18000m because of the angle of fall from the shells. Up from 18000m the shell can penetrate the upper belt.

Nevertheless, both the Bismarck and the Scharnhorst were delivered fatal blows at ranges of less than 18000 metres, which sort of contradicts your foot stamping dont you think???? Why would the Alaska be any different, given her guns were superior to the 14/50 in this regard.


Alaska has a high main deck on the main belt of 229mm inclined. So a shell from 18000m or less can penetrate the main belt and goes under the main deck through the ship.
And this is the difference to SH because a shell that penetrates the main belt must also go through the low main deck and the torpedo bulkhead to go through the ship!

No argument that the Alaskas defensive arrangements are inadequate, but as the table extracts above show, the 28cm AP characteristics at range are going to have difficulty with the Alaskas schemeSo I ask you again....how can the DoY with a gun of lesser capability do telling damage on the Scharnhorst except if the armouring scheme was vulnerable....


This are the facts from navy weapons parsifal no myths. Or do you think the data of the Mark8 are not true?
This data are with the 1,140 lbs. (517.093 kg) shell with 2,500 fps (762 mps).


The myths that come up again and again, just barely below the surface, is that the german ships were impreganable. that this is an obvious myth is clear for all to see, yet it never ceases to amaze me the denial that goes with al things German. German ships in service proved to be not as well protected as this discussion would suggest.

Therein lies your myth


This was up from 18000m or her turrets and there is no secret that the turrets of SH were a weak point.

As were a lot of other aspects in her design

So this discussion was for the range 18000m or less!

For me the discussion was whether the Alaskas 12/50s have the power to overcome the Scharnhorst. I could not see any great advantage at any particular range, but suggested that if the US ship wanted to bring its 5/38s into play it should aim for a range of about 18000 yards....but was not certain that was such a good idea or not. Seems not after all this discussion and information. Does not alter me from the same basic supposition...that the 12/50 had more than enough power to deal with the Scharnhorst.

Let me make something very clear....i am not saying the fight would be a foregone conclusion, merely that the advantage in my opinion lays with the Alaska, primarily because of the power and accuracy of her gunnery systems.

 

[parsifal]

Whats this parsifal? Do you want to provoke?
You are talking nonsens in this post.

Not wishing to provoke anybody, but neither am I going to accept what is essentially propaganda. Dont react well to people using derogatory terms like "talking nonsense" either, when the sources are there to refute neasrly everything that you uber germans say

Are you saying that the Bismarck in her last fight was not silenced easily....its a fact. battle commenced 0854, last salvo from the Bismarck was 0931....knocked out as a battleworthy unit in 37 minutes.....the fact that her hull could then absorb tremendous punushment is academic in my book .

Same basic principals apply to the Scharnhorst

 

[Njaco]

Whats this parsifal? Do you want to provoke?
You are talking nonsens in this post.

Lets keep this civil or yet another thread will be closed. Deal with facts and not personal attacks. This is a good thread that is generating a lot of thought provoking info and it would be a shame to close because name-calling became a routine.

 

[Glider]

A couple of observations on the penetration debate that is going on.

It certainly seems that the 12in on the Alaska had a remarkable penetration performance for a gun of its size. However having penetrated the armour you need to do the damage. The 12 AP shell weighs a lot less than the 14in shell about 75% the weight. There has to be a payback for this AP preformance and that is the amount of explosive in the shell. The 12in AP only had about 40% of the explosive of the 14in so the damage each hit will inflict is considerably less. It would be wrong to consider the 12in to have a superior performance than the 14in. Indeed the explosive content of the 11in AP shell was very similar being approx 80% of that in the 12in.

Then you have to consider the basic design of the armour. The USN designed their ships on the all or nothing principle so the vitals were protected leaving the other parts of the ship vulnerable with little or no armour. The Scharnhorst had a more traditional layout and its probable that she could withstand a 12in shell better than the Alaska could take an 11in hit.

To sum up it would be a major assumption to say that because the DOY was able to knock out a part of the Scharnhorst the Alaska would. The damage each shell would inflict would be much less.

 

[Juha]

Hello Glider
I agree with most what you wrote but one idea behind all or nothing armour was that weak armour was sometimes detrimental because not only it doesn't prevent penetration but it also activate fuzes, so it guarantee detonation of the shell inside a ship. An AP hit on the unarmoured part of a ship might well went through the ship without detonation if it doesn't hit something fairly substantial. Of course the shell and secondary splinters will do some damage but that is normally less than that produced by detonating shell.

Juha

 

[Glider]

A good point but I believe that they normally went off, there are plenty of things inside a ship that would be sufficient to detonate the shell. It would almost imply that the French unarmoured cruisers were a good idea.

 

[DerAdlerIstGelandet]

you uber germans say

Now I am drawing the line. DonL is getting out of hand. Njaco already confronted him. Now I will confront you. You are making it personal now, I will not tollerate that! I will ban both of you! I will not tolerate such talk about anyones nationality. If you don't like Germans, Americans, or anyone else, keep it to your self!

Do you understand?

 

[Vincenzo]

I already write this Parsifal, reading accurate naval weapons the tabel of US 12" and british 14" aren't in same conditions and methods so it's not true that US 12" it's best of british 14"

 

[parsifal]

agree that the 12in AP would probably have less blast effect than an SAP round, or an AP round with more explosive. I dont know what damage a penetrating shell would have, but your right, I think Scharnhorst would stand up to damage better than Alaska.

Having said that, the Scharnhorst is giving up a lot in firepower, and accuracy. Her shells are 727 lbs each to the Alaskas 1140, so if both were using AP rounds because they needed to penetrate to the vitals, both ships would inflict proportionally les damage per hit. If the Scharnhorst hits the main belt at its thickest, it probably wont penetrate (depending on the range, as the above discussion has shown). If it does penetrate, the lack of secondary protection in the US ship will see a lot of damage internally per hit.

Conversely, the Alaska can expect to to hit around four times for every hit achieved by the Scharnhorst (at least thats what it looks like), and each hit is likley to at least penetrate the belt, though as our german friends point out the sloped deck also provides good secondary protection.

So I am not sure who will win a fight of this nature....a lot seems to depend on the luck really and the conditions on the day. Poor weather helps the Alaska, good weather evens things up. The range at which the fight occurs might also affect the outcome, though I havent completely figured out the optimum range for either ship....