Scharnhorst and Nelson. Same weight, very different power

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alecsandros
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Scharnhorst and Nelson. Same weight, very different power

Post by alecsandros »

Hello all,

I've been reading for several days on your board and it's great! So many nice info and pictures mostly about world war 2 naval battles - one of my oldest hobbies.

I hope I can contribute to this forum's development.
=================

My first post is concerned with the relationship between displacement and overall warship power (armor, guns, machinery hp, etc). More specificaly, I find it very odd that Scharnhorst and Nelson shared almost the same tonnage, whereas Nelson is both much more potently armed and armoured!

So, what do you think? How did Scharnhorst get such a "fat a*s"?
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by lwd »

Scharnhorst is a fair amount faster. Engine power for BBs is not cheap in terms of weight. The Nelson's also used a rather extreme version of the "all or nothing" armor scheme which the German BBs did not.
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marcelo_malara
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by marcelo_malara »

Welcom to the forum. I think that one reason is that you don´t save much weight reducing the caliber of the barrels. The 16" barrel weights 106 t, the 11" 53 t, so in 9 barrels you save around 450 t. Another reason is that the armour of Scharnhorst is longer because of the turret distribution. Finally there are differences in machinery, Schanhorst has a total of 135.000 hp against Nelson´s 45.000.
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Bgile »

marcelo_malara wrote:Welcom to the forum. I think that one reason is that you don´t save much weight reducing the caliber of the barrels. The 16" barrel weights 106 t, the 11" 53 t, so in 9 barrels you save around 450 t. Another reason is that the armour of Scharnhorst is longer because of the turret distribution. Finally there are differences in machinery, Schanhorst has a total of 135.000 hp against Nelson´s 45.000.
There is a lot more to the weight of armament than just the gun tubes. That is why an installation of six 15" guns was significantly heavier than nine 11" guns when they designed the conversion for Gneisenau. Obviously nine 16" would be even worse.
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Kyler »

Scharnhorst had a 31+ knot top speed v Nelson's 23 knot top speed on a good day.

The weight of the additonal engine machinery really adds up.

Scharnhorst had 12 boilers & 3 turbine to Nelson's 8 & 2 turbines

Scharnhorst didn't have to fight, she just to had to flee again better armed vessels, which it did on many occasions during WW2
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Wrong f@%king ship!" Commander Stewart-Moore (HMS Ark Royal)
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Bgile »

Kyler wrote:Scharnhorst had a 31+ knot top speed v Nelson's 23 knot top speed on a good day.

The weight of the additonal engine machinery really adds up.

Scharnhorst had 12 boilers & 3 turbine to Nelson's 8 & 2 turbines

Scharnhorst didn't have to fight, she just to had to flee again better armed vessels, which it did on many occasions during WW2
Yes, and failed to escape once.
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Karl Heidenreich »

There are several assumptions regarding the different designs of both vessels. Nelson and Rodney were born to be 35,000 ton BBs since day 1. Also they were armed with 16" because, when they were planned, the Japanese were already ongoing with Nagato and Mutsu, both 16" and the USN had their own 16" BBs. So, in accordroubled ance to the 1921-1922 Naval Treaty the British were entitled to have their 16" gun BBs.
But in order to do so, mounting the 16", the British sacrificed a both: machinery and armor, which is why they got that strange arragement with three triple turrets on the front of the ship.

On the other hand the Germans were working not in a 30,000 ton + BB with 15", which is a false assumption, but in a 26,000 ton vessels with 11". The idea of mounting the 15" came much, much later and was never carried on. In fact, in order to carry it on the Germans would have to made several modifications like enlarging the ship by 10 meters and working on her stability. They were ships apart my a world. Schanhorst and Gneisenau were pretty much troubled designs.

Best regards,

Karl
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Terje Langoy
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Post by Terje Langoy »

Scharnhorst and Nelson. Same weight, very different ... naval treaties in effect, constructional history, design limitations, political ambitions, etc.

From the outset 1933 - 34 the Scharnhorst (or should I say Panzerschiff D...) was not rated at 26 000 tons but at some 19 000 tons. On paper she resembled an enlarged pocket battleship complying to the German Fleet Plan of November 1932, which had called for the construction of six such vessels in all. A large portion of those 19 000 tons could be found in the speed parameter set (30 knot +) which inevitably set the choice of propulsion plant for the design - the high-pressure steam plant - a plant that consumed quite a few tons more than the previously applied diesel but also was the only one able to produce enough power. It also meant a reconstruction of the compartmentation since available space now became a crucial factor.

During the construction of the pocket battleship primary focus had at all times been saving weight - by applying diesel, welding the hull etc. However, with Scharnhorst this switched towards speed. Why..? Because the French had been building themselves a pocket-buster. And with the Versailles Treaty still hanging over the German engineers like a ghost of the past they now had to figure out how their ´next´ pocket battleship should be able to cope with this new French peril while not provoking international powers. They had to counter it somehow but the diesel was too slow and if speed was to be a top priority then more weight (increased armor) was a no-no. So forth the only options were to either increase gun calibre or utilize speed at the expense of guns and armor. The choice finally fell on increased speed, a solely defensive measure and that was basically the only difference between the first design of the Scharnhorst (1934) and the previous pocket battleship.

Despite the idea of speed superiority Admiral Raeder continued to be bothered by the fact that he was about to build a ship that, confronted by the enemy, would not be able to do anything than show the enemy its superior ability to flee. So at a conference in July 1934 he seized the opportunity to address Hitler on the matter urging him to permit a larger design, with improved offensive capabilities, to be built despite the treaty limitations. From a naval construction point they were heading down a blind alley. At this meeting Hitler was in fact presented with various design sketches where even 380 mm guns were proposed - which again verify the fact that Admiral Raeder at this point actually wanted to build a battleship. In fact the entire navy wanted to build a battleship - all that kept them back was politics, or more correct diplomatic caution. Any severe violation, such as the building of a battleship, would be a grave insult to the treaty and could reap serious international repercussions so Hitler maintained a tight leash on his Admirals ... for now. He did however recognize the naval paradox they were about to build and thus permitted a third 283 mm turret to be brought aboard the design.

With the third turret permitted the design had to be revised. She received the turret, she received further armoring as the length of the citadel now had been increased and weight steadily climbed up towards 26 000 tons. During the second keel being stretched (1935) Scharnhorst received the designation battleship for the first time - though that may be on account of the sheer size of the vessel and possibly also future plans of an upgrade. What we can state with certainty is that Scharnhorst had good armor and speed but a mediocre punch, so forth representing the direct opposites of H.M.S. Nelson.
Last edited by Terje Langoy on Sat Oct 17, 2009 1:12 pm, edited 1 time in total.
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Karl Heidenreich »

Let´s remember that the Germans built the Schanhorsts in order to deal with the French Dunkerkes. The idea to fight the British never pass through the minds of the Germans when these BB (or BC?) were built.
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by lwd »

Karl Heidenreich wrote:Let´s remember that the Germans built the Schanhorsts in order to deal with the French Dunkerkes. ....
They seem rather poorly suited to that task. Are you sure?
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Karl Heidenreich »

That´s why I haven´t done a complete post on Schanhorst yet. Basically that´s what the Germans intended but it wasn´t really needed at the end.
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Terje Langoy
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Post by Terje Langoy »

lwd wrote:
Karl Heidenreich wrote:Let´s remember that the Germans built the Schanhorsts in order to deal with the French Dunkerkes. ....
They seem rather poorly suited to that task. Are you sure?
What fuels the notion that the Scharnhorst class would be inferior to the Dunkerque class..?
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Re: Scharnhorst and Nelson. Same weight, very different power

Post by Karl Heidenreich »

Terje:
What fuels the notion that the Scharnhorst class would be inferior to the Dunkerque class..?
In the case of lwd the Schanhorst inferiority notion likely came from the lack of a US flag flying high on the mast and that it´s not considered worth a capital ship from Okun or another navweaps common wisdom post.
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Re:

Post by lwd »

Terje Langoy wrote:
lwd wrote:
Karl Heidenreich wrote:Let´s remember that the Germans built the Schanhorsts in order to deal with the French Dunkerkes. ....
They seem rather poorly suited to that task. Are you sure?
What fuels the notion that the Scharnhorst class would be inferior to the Dunkerque class..?
Well that's not what I said. As a general rule however when you build a ship to "deal" with another ship class you try to build one that is distinctly supperior to the one you are trying to deal with. In this case lets look at the two classes. I'll use wike becasuse it's quick and easy if someone can find better stats pls list them.
http://en.wikipedia.org/wiki/French_bat ... _Dunkerque
http://en.wikipedia.org/wiki/German_bat ... charnhorst
Scharnhorst Displacement: 31,552 tonnes Dunkerque Displacement: 36,380 tonnes
Scharnhorst 33 knots Dunkerque Speed: 31 knots
Scharnhorst: 9 × 28 cm/54.5 Dunkerque: 8 330mm
Scharnhorst Main belt: 350 mm Dunkerque: 225 (283 Strasbourg) mm
Scharnhorst deck: 95 mm max Dunkerque deck: 125-115 (137-127 Strasbourg)

Scharnhorst has a slight edge in speed and in thicker belt. The French ships are bigger, have thicker deck armor and bigger guns.

Looking at
http://www.navweaps.com/Weapons/WNGER_11-545_skc34.htm
http://www.navweaps.com/Weapons/WNFR_13-50_m1931.htm

It looks like the Scharnhorst can penetrate Dunkerque's belt out to either 22,000 yards or 29,000 yards and Strasbourg's out to 17,000 yards or 20,000 yards
The French on the other hand can penetrate Scharnhorst out to around 25,000 yards. So Scharnhorst may have a slight edge of Dunkerque but Strasbourg has the edge over the twins.
As far as decks go the French ships cannot be penetrated at any of the ranges give in the links above while the German decks can be penetrated at under 25,000 yards ( to be fair the angle of fall here is likely to prevent an acutal penetration).

The Germans do have 9 guns to 8 but we're also looking at 330kg vs 560 kg and bursters of 16 kg vs 20.3 and muzzle velocities of 890 vs 870 mps but by 10,000m the French round is moving faster.

All of the above make me think the German ships would be hard pressed to "deal with" the French ones.
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Re: Re:

Post by alecsandros »

lwd wrote:

The Germans do have 9 guns to 8 but we're also looking at 330kg vs 560 kg and bursters of 16 kg vs 20.3 and muzzle velocities of 890 vs 870 mps but by 10,000m the French round is moving faster.

All of the above make me think the German ships would be hard pressed to "deal with" the French ones.
Yeap, think so to.
And that puzzles me even more: it seems like the best ships that Scharnhorst was able to destroy with certainty were heavy cruisers :shock: Almost 40.000 tons against 10.000... Those 283mm guns were realy bad in fighting big ships.

Perhaps they weren't designed to fight big ships, but to chase convoys and sink escorts. (just a guess)

Cheers
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