Tirpitz shelling New York

Historical what if discussions, hypothetical operations, battleship vs. battleship engagements, design your own warship, etc.
yellowtail3
Senior Member
Posts: 408
Joined: Wed Oct 28, 2009 5:50 pm
Location: North Carolina, USA

Re: Tirpitz shelling New York

Post by yellowtail3 » Tue May 22, 2012 2:09 am

alecsandros wrote:for comparison with US 14"/L50 and US 16"/L45 2240lbs:
http://www.navweaps.com/index_nathan/Pe ... States.htm

Look at "US EFF", distance 20000 yards for all guns.
I looked at it, though I'm not sure what to make of it. Is this explaining how the USN's 14"/50 AP shells would behave badly in high obliquity?

I was actually influenced by that same writer - Okun? - on the virtures of the 14"/50, when it comes to penetrating armor:
http://www.combinedfleet.com/okun_biz.htm
The best all-round WWII armor-piercing projectiles were the U.S. designs. They were less able to remain in effective bursting condition after penetration than British projectiles, but they remained rigid under very difficult impact conditions and could penetrate armor of much greater thickness at much higher obliquities than anyone else's. For example, at least one WWII U.S. 14" Mark 16 MOD 8 capped armor piercing projectile (APC in British and U.S. Army nomenclature, but AP in U.S. Navy nomenclature, since the U.S. Navy assumed an AP cap was always used on a "true" AP projectile) penetrated intact through a WWII U.S. 13.5" (343 mm) Class 'A' plate at 49o obliquity at barely above the NL, which far exceeded any foreign design capability that I know of.

German armor-piercing projectiles were good at penetrating armor at low obliquity (under 30o), but their ability to penetrate or remain in effective bursting condition afterwards dropped off quite rapidly as obliquity increased, especially against thick (over projectile diameter in thickness) armor.

British projectiles were very good at low obliquity (under 35o) against plates up to their diameter in thickness. At higher obliquity against such plates, they broke up or glanced off or both. British armor-piercing projectiles were even worse than German projectiles against thicker plates at all but nearly exact right-angles impacts. For example, the 14" size was found in post-WWII U.S. testing to be absolutely incapable of penetrating the thick U.S. Class 'B' turret faces or Class 'A' barbettes (17.3-19.5" (439-495 mm) thick) at even a moderate 30o obliquity, bending into "bananas" and breaking rather than punching through at striking velocities at which the equivalent U.S. 14" Mk 16 MOD 8 armor-piercing projectiles were staying rigid and passing right through, though the U.S. projectiles were usually rendered ineffective unless they penetrated at well above the NL. Neither British or German projectiles were designed for use against such heavy armor and had larger explosive charges for increased damage on penetration than the U.S. projectiles had. This lower capability of British and German projectiles seems to have been a lingering result of the restrictions of the Washington Naval Treaty of 1922, especially for the British
Shift Colors... underway.

alecsandros
Senior Member
Posts: 4349
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Tirpitz shelling New York

Post by alecsandros » Tue May 22, 2012 5:40 am

Hello,
Don't take it to the heart.

Nathan himself made revisions of his own posts (like "decapping" and "decapping revisited" several years later. The paper on Bismarck and other BBs comparison was also put to the wall on several forums, including this one. He admited "things are much more complicated" than he originaly took into consideration.).

If you examine the file with the 14" shells, you'll observe several failures, allthough obliquity did not exceeded 35*.

The shells had relatively pointed tips, and long bodies. Filler cavity was also relatively small. All those elements combined made them not funciton well when striking beyond some reasonable obliquties.

I posted the US EFF limit for comparsisons of armor penetration capabilities. THe British 14"/L45 could perforate 16.8" of armor at 20000 yards, while the US 14"/L50 - 15 inches of armor.

yellowtail3
Senior Member
Posts: 408
Joined: Wed Oct 28, 2009 5:50 pm
Location: North Carolina, USA

Re: Tirpitz shelling New York

Post by yellowtail3 » Tue May 22, 2012 12:41 pm

alecsandros wrote:I posted the US EFF limit for comparsisons of armor penetration capabilities. THe British 14"/L45 could perforate 16.8" of armor at 20000 yards, while the US 14"/L50 - 15 inches of armor.
Well... that oughta to be enough to prevent Tirpitz from shelling Manhatten! You're thinking all those performance figures I quoted from Navweaps are bogus?
Shift Colors... underway.

alecsandros
Senior Member
Posts: 4349
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Tirpitz shelling New York

Post by alecsandros » Tue May 22, 2012 1:02 pm

No, they aren't bogus, just that things are more complicated.

User avatar
RF
Senior Member
Posts: 7603
Joined: Wed Sep 20, 2006 1:15 pm
Location: Wolverhampton, ENGLAND

Re: Tirpitz shelling New York

Post by RF » Tue May 22, 2012 5:35 pm

alecsandros wrote:
RF wrote:That closing of the range to get those vital big hits quickly also depends on good gunnery from Tirpitz which on the record of that ships actual history could be a problem.
What closing of the range ?
Tirpitz had formidable gunnery precision at 25km against target-ship Hessen. [Why do you think all the Arctic convoys that transited in times in which Tirpitz was operational were covered by 2 BBs, out of which 1 was mandatorily a 16" battleship ?]
Bismarck, with the crew insufficiently trained, straddled and sank Hood (a very fast moving, and manouvreing target) at 16-18 km distance.

NM would have been blown to hell before it could find the range.
Maybe. Maybe not.

If you read Salhearts' post on page 4 you will see the context of my comment as we are not talking of a target ship here.

By what measure were Bismarcks' crew insufficiently trained??
''Give me a Ping and one Ping only'' - Sean Connery.

ede144
Member
Posts: 152
Joined: Mon Oct 10, 2011 5:09 pm

Re: Tirpitz shelling New York

Post by ede144 » Tue May 22, 2012 6:49 pm

RF wrote:
By what measure were Bismarcks' crew insufficiently trained??
The KM considered 2 years necessary to work up a new ship and train it's crew to combat readiness. BS was taken over by the KM at Aug. 24 1940 and the orders for Rheinübung were dated April 22 1941 which is hardly 8 month with some idle time in the winter in the Baltic. The Baron mentions the lack of crew training after the torpedo hit at the rudder and the usability to solve the problems related to it.

Regards
ede

alecsandros
Senior Member
Posts: 4349
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Tirpitz shelling New York

Post by alecsandros » Tue May 22, 2012 7:08 pm

RF wrote:
By what measure were Bismarcks' crew insufficiently trained??
They hadn't completed their main gunnery test firings and AA systems training.
They did some of that in Nov-Dec 1940, but numerous defficiencies were observed and marked for improval.
Only in late March 1941 could the Bismarck return to tests in the Baltic, hastily done (finished on the 2nd of April)

From AVKS-700, we know that the second trial period was planned as 19.03 - 11.04.1941.
However, because of the new orders from OKM (i.e. preparing for Rheinubung), tests had to be cut short on 2nd of April.
Because of this, "a considerable portion of the intended tests had to be abruptly dropped".
"Flak shooting tests were not evaluated with the thoroughness that is mandatory and customary during AVKS firing"
"Shot group firing to determine shot dispersion [...] had to be stricken", etc.

Basicaly, the ship was far from being fully battle-ready in May 1941.

yellowtail3
Senior Member
Posts: 408
Joined: Wed Oct 28, 2009 5:50 pm
Location: North Carolina, USA

Re: Tirpitz shelling New York

Post by yellowtail3 » Wed May 23, 2012 12:55 am

alecsandros wrote:No, they aren't bogus, just that things are more complicated.
I understand, alecsandros, and can appreciate that - but in fact, they're nowhere near as complicated as you're making them out to be.

Most of us here are interested in this stuff - how hard, how far, how much, which shell is x percent better than the other, which can be pronounced better - it reminds me of guys (like myself) who have similar conversations re: big game rifles. They'll talk themselves blue in the face of relative merits of 8mm Mauser, 30-30, 30-06, .308, 7mm-08, 6.5 Swede, .270, 7.62x54R, etc etc etc... when in fact, at the ranges most guys can hit a heart-sized target, there's not much difference on medium-sized game. I think it's prob about the same with battleship guns; for most applications, there ain't a whole lot of diff. Do you really believe a Yamashiro would have been disabled sooner by like number of 15" French of Germans shells? Or that Bismarck would have lasted longer if she was being shelled by USN 16" and 14" shells, rather than RN ones? I don't. Anyhow... let's pursue this a bit:
alecsandros wrote:I am by no means an "expert", but my opinion is that quality matters more than quantity in this kind of battle. Not just quality of the guns, but more importantly quality of the battery and of the fire control system.

Of course it's good to have 12 shells in the air instead of 8, but what do you do if you can't find the range, while the enemy allready has you "in the sights" ?

New Mexico and her sister-ship Idaho performed shootings in the 30s and 40s, and the results weren't to good. Dispersion was high, rate of fire slow, and misfirings often.
Bismarck and Tirpitz on the other hand fired very accurate salvos, with high rate of fire and with fewer misfirings.
we should compare like events. Assuming you are talking about that test where one of the New Mexicos empited forward magazines (?) .... are there comparable trials on one of the KM ships, where we konw how many shells were fired and how 'misfires' occured, and what the rate of fire was over the whole event? I'm not aware of any, but I'll be glad to learn of them. ALSO - this bit about 'dispersion' - was this not fixed by the modernized guns in the New Mexicos? I'd read that they were - it was a blurb at Navweaps 0- was that not so?
Shift Colors... underway.

Byron Angel
Senior Member
Posts: 1136
Joined: Sun Mar 06, 2011 1:06 am

Re: Tirpitz shelling New York

Post by Byron Angel » Wed May 23, 2012 3:21 am

The fitting of delay coils to the 14/45 and 14/45 armed US battleships in 1935 resulted in an improvement in true mean dispersion to the point that the 14in guns were equivalent to the new 16/45 and 16/50. This was validated by analysis of the battle practice results from 1936 through 1941, whereby the data taken from each exercise exclusively involved firings of multi-turret salvoes with all guns of each participating turret firing, using service AP projectiles and full service charges, i.e. - as close to action conditions as could be achieved in peacetime exercises. The report was prepared by Princeton University on behalf of the Applied Mathematics Panel of the National Defense Research Committee (AMP Report No. 79 2R; SRG-P No 42, July 1944).

B

Saltheart
Member
Posts: 88
Joined: Sat Jun 18, 2011 1:46 am
Location: New Zealand

Re: Tirpitz shelling New York

Post by Saltheart » Wed May 23, 2012 3:52 am

Okay so it looks like New Mexico would be firing competitively tight salvos with 12 powerful high velocity guns in reliable mountings. It would have modern fire control and a very experienced crew. It's also a smaller target and being a standard battleship it's good and manouverable. The shells it fires also hold together exceptionally well while penetrating thick armor.
Apart from all that what has the New Mexico ever done for us? :wink:

Right, but seriously. We know Tirpitz can be silenced by multiple shell hits amongst it's turrets and barbettes because the Bismarck was. We also know from what happened to Bismarck that Tirpitz will be very hard to sink. It will absorb a lot of punishment even if it's turrets are out and it will keep running for open sea.

So if all the above about New Mexico's quality is true and she has arrived and is blocking Tirpitz's route out to sea, how effective is Tirpitz's gunfire going to be against this modernised standard? Let's say they're shelling each other full tilt and Tirpitz has not yet been silenced. At what range will it penetrate the turret faces, the belt and the superstructure on the US ship? Can Tirpitz, if it is getting hits, wreck the New Mexico?

alecsandros
Senior Member
Posts: 4349
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: Tirpitz shelling New York

Post by alecsandros » Wed May 23, 2012 6:22 am

yellowtail3 wrote: Bismarck and Tirpitz on the other hand fired very accurate salvos, with high rate of fire and with fewer misfirings.
we should compare like events. Assuming you are talking about that test where one of the New Mexicos empited forward magazines (?) .... are there comparable trials on one of the KM ships, where we konw how many shells were fired and how 'misfires' occured, and what the rate of fire was over the whole event? I'm not aware of any, but I'll be glad to learn of them. ALSO - this bit about 'dispersion' - was this not fixed by the modernized guns in the New Mexicos? I'd read that they were - it was a blurb at Navweaps 0- was that not so?[/quote]

I don't know of any truly comparalbe test.
What can be compared though is the availability of the guns for correct shootings.

- Friedman in "US Battleships", mentions that Idaho had available, on average, 4-5 main guns out of every "end" of the ship, in the first 60 minutes or so. 4 guns out of 6 makes 67% shells actualy fired. 5 out of 6 makes 83%.
The best salvos had 5 guns, the worst (late in the test) - only 1 gun...
Average interval between firings of the same gun was 1m 24s.

- Garzke's study of US BB's gunnery systems shows the patterns of 14"/L50 shells fired at 14.5 - 18km range. Spread was 2.5% of range at said ranges for full-battery firings, and 1.5-2% of range for 3-gun and 6-gun salvos.

Accuracy was moderate. The target sled moved at 16-20kts maximum, with few to no manouvreings.

- There were continual improvements in the efficiency of old US BBs throughout the war.
They adressed the problems of blind fuzes, precision-firing at long range, perforative performance of the shells and offered superior crew training.

However, the performances at Surigao Strait showed that there was still much work to be done (initialy 3 of the 6 BBs could not aquire target - Yamashiro - because their fire control systems weren't as advanced as the ones operating on the other 3 BBs; the actual number of shells fired against Yamashiro was ~ 280. The total number of hits is disputed, but the effectiveness of the shooting was less than expected from such a heavy barrage.)
===

Bismarck fired 93 shells at DS, out of a total of 104 possible. That's 89%. That was about the average performance of battleship shooting during WW2.

AVKS test performed on Bismarck in March 1941 on Gotenhagen showed the total rate of transfer of 38cm shells from the main magazines to the turrets was 23-25 shells/minute. That's 2.9 - 3.12 shells/minute/gun.
This can give an idea about the firing interval between shells during this AVKS test firing.

Tirpitz firings showed spreads of 100m or less from 4-gun turrets at 20km range.

Accuracy of the firing of Bismarck was not satisfactory for OKM in Apr 1941. There were problems at the remote control systems for the main guns, which I don't know if were corrected until Rheinubung.

In the actual battle, Bismarck fired 93 shells, at ranges 14-20km, scoring 4 certain hits and 2-3 other possible but unconfirmed. The targets (Hood and PoW) were traveling at 28-29kts, and made 2 alterations in course.

~~~~~

Tirpitz's gunnery also raised problems in April 1941. Only in Sept 1941 were the problems corrected, and OKM satisfied with the overall efficiency of the main guns.

~~~~~

Bismarck and Tirpitz had remote controled main guns, with elevation determined and set automaticaly by the fire-control computers.
Precision of the German range-finders and radars was very good in 1942.

~~~~~

Tirpitz could probably make 30kts+, while New Mexico 21kts.
Range could easily be dicated by the Germans.

~~~~
Armor quantity and quality was markedly superior on the German ship.
Vertical protection covered 70% of waterline. Defense system comprised of 145-320mm main belt KC n/A armor, backed by teak wood, and construction steel.
Behind it were further 30-120mm thick armored bulkheads/scarps.
Horizontal protection featured 50mm Whotan weather deck (with some 80mm portions), 20mm battery deck (only near the centerline), and 80-100mm thick Whotan panzer deck. The distance between decks and the metallurgical properties of the materials employed assured decaping and yaw of any incoming shell, striking at obliquties of 60* or more from the normal.

Turret geometry was very original and offered very few strait surfaces for the shell the burrow itself in. Armor thickness was up to 360mm.
Con tower had 350mm thick walls.
The main communication tube was armored with 220mm thick walls. INternal portion of barbettes was also 220mm thick.

Properties of Whotan and KC n/A, according to British tests post-war showed them to be at least equal to British contemporary (post 1930) plates.

~~~~

Armor scheme on New Mexico followed the WW1 design ideas.

Upper decks were completely unarmored.
Deck thickness 90mm.
Armor belt 340mm, equivalent to 290mm US class A (at best).
Con tower 400mm, equivalent to 340mm
Turret face 450mm, equivalent to 360mm

Lower hull completely unarmored.

Byron Angel
Senior Member
Posts: 1136
Joined: Sun Mar 06, 2011 1:06 am

Re: Tirpitz shelling New York

Post by Byron Angel » Wed May 23, 2012 11:39 am

It seems to me that all this debate about TIRPITZ versus NEW MEXICO begs the real issue. The greatest danger to TIRPITZ would be the several 16in coastal batteries covering the sea approaches to NY. They were very accurate, largely impervious to any TIRPITZ return fire, and represented a real threat to any ship operating 3,000+ miles from its nearest safe port.

BTW - along the lines of comparing WW1 era BBs to WW2 era BBs, when shall we schedule the comparison of, say, SMS BADEN versus USS WASHINGTON? I'd personally be fascinated.

B

Thorsten Wahl
Senior Member
Posts: 762
Joined: Mon Apr 27, 2009 4:17 pm

Re: Tirpitz shelling New York

Post by Thorsten Wahl » Wed May 23, 2012 1:35 pm

Bismarck ROF
in general according Unterlagen zur Bestimmung der Hauptkampfentfernung...
ROF: ~ 2 Schuss/Minute

achieved
Vermerk für OB. d.M. Überschwere Kaliber für Kriegsschiffneubauten 06.11.1942 B.Nr. 7763-42 gKdos
(Note to OB. d.M. over-heavy caliber guns for new ships (45cm and 50 cm)

turret 38 cm SK C/34 in Drh. L. C/34f (Tirpitz)
shot sequence in loading arrangement 2,5°: 24 s
shot sequence at 15° barrelelevation: 30 s
shot sequence at 30° barrelelevation: 35 s

permanent delivery speed of ammunition hoists
planned according Bauvorschrift Schiffskörper one projectile per 26 sec
achieved according AVKS 23-25 shells per minute all guns; 19 - 21 sec
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

User avatar
Dave Saxton
Supporter
Posts: 3093
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: Tirpitz shelling New York

Post by Dave Saxton » Wed May 23, 2012 2:15 pm

Saltheart wrote:A weakness in Bismarck was that the stern was structurally weak. It eventually collapsed after the fatal torpedo hit. I think Prinz Eugen's stern also collapsed after a submarine torpedo hit off Norway.
Maybe if New Mexico (firing from the Pacific) hit the stern it could mean Bismarck heads home basically dragging a bag of wreckage behind it.
There is no evidence of Bismarck's extreme stern detaching before it sank. The sterns of German warships that collapsed such as on cruisers Prinz Eugen or Luetzow did so as a result from torpedo hits. There's nothing unusual about that. American cruisers lost entire bows back as far as the number 2 turret as a result of toredo hits. Portland had its stern bent into an L shape. Torpedo hits do such things.
Last edited by Dave Saxton on Wed May 23, 2012 2:30 pm, edited 1 time in total.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

Thorsten Wahl
Senior Member
Posts: 762
Joined: Mon Apr 27, 2009 4:17 pm

Re: Tirpitz shelling New York

Post by Thorsten Wahl » Wed May 23, 2012 2:19 pm

[quote="Saltheart] A weakness in Bismarck was that the stern was structurally weak. It eventually collapsed after the fatal torpedo hit. I think Prinz Eugen's stern also collapsed after a submarine torpedo hit off Norway.
Maybe if New Mexico (firing from the Pacific) hit the stern it could mean Bismarck heads home basically dragging a bag of wreckage behind it.[/quote]

As far as I know no unarmored shipstructure of about 10 m width and 7 m heigth is able to widthstand the detonation of a torpedo.
if you compare to the effect of the torpedoimpact making a hole in the bow of Gneisenau during Operation Juno
http://www.scharnhorst-class.dk/gneisen ... ejuno.html

The detaching of the stern section apparently didnt affect the watertight integrity of the nearby bulkhead on Bismarck and also buoyancy
of the Prinz was not critically affected.

It appears to me as being not critical if I compare this damage with the "normal" effects of even a single torpedoexplosion. The loading was exceptional high.

Which does not mean that no improvements could be made to improve robustness.
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

Post Reply