Naval History Forums

I just finished reading Warren Tute's book "Deadly Stroke" about the RN's attack on the French fleet at Mers-el-Kebir (sp?), and was impressed with what I read about the Dunkerque and Strasbourg.

I'd be interested in the group's opinions as to how these two French ships would have fared vs the S & G twins.

Derf

An interesting line up, as the "twins" were built to counter the Duetschland killing Dunkerque's. Bear in mind that Strasbourg was the more formidable of the French pair as she was better protected, and faster as memory serves me.
Gunnery proficiency- I'll go with the Germans in this category. The little that I've been able to find on French gunnery performance states that all the French quadruple turrets had problems with excessive salvo spread. As you know, this was not an issue with the Germans. Neither nation had a gunnery radar that was woth a cup of bilge water, so that shouldn't be a factor.
Ballistic Performance- Better in the French ships of course, but the thicker German armor would compensate for this. The heavier armament in the French ships would be meaningless if their hit ratio was low.
Speed-A slight edge for the Germans over Strasbourg, and perhaps a couple of knots over Dunkerque.
The French had better hope they wouldn't have to make a run for it, since they'd be just targets in a running stern chase. The Germans however could continue the action with their aft turrets. In good steaming conditions Strasbourg could probably catch Gneisenau, but not Scharnhorst.
I'd say the Germans would hammer the French, which the German 283mm was quite capable of doing. Neither side had a main armament range advantage. The trick would be to persuade the French to try to break off the action, then walk salvos up their wakes into the poorly protected sterns...all this while the French were unable to reply with anything larger than the secondary batteries. The after transverse bulkheads in the French ships were weak, and potentially an Achille's Heel. Hammer them aft and they might sink by the stern.

What do you mean with catch Gneisenau but not Scharnhorst? Their topspeed were the same!

Frankly, the real situation would likely be "catch Scharnhorst, but not Gneisenau" ! Scharnhorst's engineering plant was more likely to break down or not be at full availability than Gneisenau's as I understand it.

As far as I know, both the "Twins" should have been able to run away from either Strasbourg or Dunkerque all things being equal.

Derf

"The trick would be to persuade the French to try to break off the action, then walk salvos up their wakes into the poorly protected sterns."
Yes, that would be quite a trick. "Hey, Strasbourg, I think I just heard your mother calling you." "Dunkerque, look back there--it's Jerry Lewis." Then the hard part is convincing them to keep their sterns toward the enemy who's shooting at them. I haven't figured that one yet.

Tiornu, a difficult scenario on the surface, but with Jerry Lewis as an incentive, it might work. I have never understood the French fascination with a performer whose work I cannot watch for 2 minutes.

Gerry

Nellie wrote:What do you mean with catch Gneisenau but not Scharnhorst? Their topspeed were the same!

Ask Tiornu, Scharnhorst was a bit faster. The same power plant, but Scharnhorst had higher SHP.

Hello, the Germans built the Scharnhorst and Gneisenau with the idea to make the Dunkerques obsolete. In normal circunstances the Scharnhorst and Gneisenau win.

It's true that the Germans intended the Scharnhorsts to be superior to the Dunkerques, but that doesn't mean they succeeded.

Hello, the Dunkerques were only superior to the Scharnhorst in the main armament 8 guns of 330 mm versus 9 guns of 280 mm. But German armament is better distributed in 3 triple turrets and has a higher rate of fire and better optics than the French in 2 quadruple turrets. In the field of speed and armor the Germans have the lead over the French in this case.

The Scharnhorsts do have a speed advantage, but that wouldn't help them in a gun battle except in their ability to break off the action. And that assumes Scharnhorst doesn't have a machinery casualty in the middle of a fight, which actually happened to her twice during the war.
I can't agree on the armor advantage. I prefer Dunkerque's system by far, especially as gauged against the shells that would be hitting it.

Dunkerque/Strasbourg

Dunkerque: 225 mm (side belt: 8.9")
Strasbourg: 283 mm (side belt: 11.15")
125-115 mm (decks: 5-4.5")
Dunkerque: 330/310 mm (turrets: 13"/barbettes: 12.2")
Strasbourg: 360/340 (turrets: 14.2"/barbettes: 13.4")
30 mm (anti-torpedo bulkheads: 1.2")
270 mm (10.6" CT)

Scharnhorst:

350 mm side belt
130/160 mm decks
340/350 mm turrets/barbettes
45 mm torpedo bulkheads
350 mm control tower

In assessing armor protection, it's important to go beyond what the statistics tell you. For example, Dunkerque's belt armor was inclined at 11deg for its full length. It covered about 1.5m more height of the ship's side than Scharnhorst's. Scharnhorst's barbette armor is angled inward to give incoming shells an easier angle to penetrate, but even if we forget that for the moment, Dunkerque's guns can effectively penetrate 350mm from distances as far away as 24,000 yards, while Scharnhorst has to be within 17,000 yards to effectively penetrate 310mm. But Scharnhorst's biggest trouble is her terrible deck protection. Her armor deck is as thin as 80mm. The numbers you are quoting appear to be adding all the deck thicknesses together in one figure.

Tiornu wrote:In assessing armor protection, it's important to go beyond what the statistics tell you. For example, Dunkerque's belt armor was inclined at 11deg for its full length. It covered about 1.5m more height of the ship's side than Scharnhorst's. Scharnhorst's barbette armor is angled inward to give incoming shells an easier angle to penetrate, but even if we forget that for the moment, Dunkerque's guns can effectively penetrate 350mm from distances as far away as 24,000 yards, while Scharnhorst has to be within 17,000 yards to effectively penetrate 310mm. But Scharnhorst's biggest trouble is her terrible deck protection. Her armor deck is as thin as 80mm. The numbers you are quoting appear to be adding all the deck thicknesses together in one figure.

Tiornu presents a convincing argument (as always!).

Let me ask - Did the respective navies of WW2 know the details of the enemy ships such as the armor thickness details that Tiornu notes? Did they know enough of the details that, for example, if the S&G twins would have happened upon Dunkerque and Strasbourg, the KM admiral would have known to be careful and use his superior speed to stay at an advantage? He certainly would have known that vs an enemy battleship group, but what about with D & S?

Derf

In some cases, featues were known in great detail. In others, even the basics were a mystery. If you can get a contemporary copy of Jane's, that often gives a good indicator of common knowledge.
The Germans seem to have thought American ships were uber-ships with absurd amounts of armor. The American never did get a feel for exactly how powerful Yamato was.
In the case of the French ships, the Germans certainly would have used their speed to stay at an advantage--which is to say, flee.