150/152 mm gun turret locations

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spicmart
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150/152 mm gun turret locations

Post by spicmart »

Reading the comparison between the Bismarck and Richelieu designs the German engineers seemed to be a bit astonished about the configuration and location of the Rich's MA guns, which enabled her to fire a 9 x 152 mm gun broadside with three triple turrets compared to the Bis' 6 x 150 mm with three twins. Thus the French ship saves a lot of weight for a heavier broadside to one side at least.
Was there a specific reason why Germany (and other nations) wouldn't adopt the French solution against the weight gain of their battleships?
The Scharnhorsts would have especially benefitted.
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Re: 150/152 mm gun turret locations

Post by dunmunro »

spicmart wrote: Fri Sep 10, 2021 4:22 pm Reading the comparison between the Bismarck and Richelieu designs the German engineers seemed to be a bit astonished about the configuration and location of the Rich's MA guns, which enabled her to fire a 9 x 152 mm gun broadside with three triple turrets compared to the Bis' 6 x 150 mm with three twins. Thus the French ship saves a lot of weight for a heavier broadside to one side at least.
Was there a specific reason why Germany (and other nations) wouldn't adopt the French solution against the weight gain of their battleships?
The Scharnhorsts would have especially benefitted.
The layout of Richelieu was aided by having all 15in guns forward but as the 152mm turrets were not staggered, they would interfere with each on some broadside bearings, especially when the target was abreast or forward of the beam. The Richelieu was able to bring a greater proportion of her 152mm guns to bear on either beam and in that sense saved weight.
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marcelo_malara
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Re: 150/152 mm gun turret locations

Post by marcelo_malara »

You mean putting one secondary turret in the center line. That is easier to do in Richelieu, it was done in the stern with no primary turrets around. To do this in Bismarck would mean that the 6" turret needs to super fire Bruno or Cesar, and that would put some weight high in the ship. Yes, it was done in Yamato.
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hans zurbriggen
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Re: 150/152 mm gun turret locations

Post by hans zurbriggen »

Hello Mr. spicmart,
Germans possibly referred to the original Richelieu design, given-up in 1939 (or they were simply wrong evaluating her capabilities).

Richelieu could bring to bear 9 guns only exactly astern (side turrets could not be trained inboard, not even by a single degee), 6 from directly astern up to 48° from bow (centre turret could train 132° both sides), only 3 guns if attacked from 48° up to 10°from bow (side turrets could train 170°), from 10° to 0°from bow there was a blind sector of 20°ahead for the 150 mm guns.
Original Richelieu design was for 5 triple 150 mm turrets (turret could elevate up to 90° and it had been designed as a double purpose one). This would have been a very good arrangement (with actually 9 guns capable of firing broadside). Shell loading problems at more than 45° elevation (due to weight) and turret slow training/elevating rate prevented to use them as a.a. guns, therefore pure a.a. guns (6 100 mm twin turrets with bad sectors ahead and astern) were installed at centre ship instead of the 2 150 mm turrets that would have been placed at beam (the only ones capable of firing ahead, with a 180° training arc).
Bismarck could use always at least 4, mostly 6 150 mm guns: a much better arrangement. Of course, double purpose guns would have allowed Bismarck to have a larger number of guns for both usages.

Same applies to Richelieu main armament, with a totally blind sector of 48° astern and another 18° per side where only 4 main guns could bear (TI): French engineers gave up the all-forward design already with the planned 4th ship of the class, Gascogne.

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Re: 150/152 mm gun turret locations

Post by spicmart »

Thanks for the answers.
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hans zurbriggen
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Re: 150/152 mm gun turret locations

Post by hans zurbriggen »

Hello Mr. Spicmart,
as an aside, third and forth ship of Richelieu class would have been finally able to fire 9 150 mm guns broadsides.
Clemenceau would have had 4 150 mm triple turrets (2 centreline aft and 2 at beam sides), while Gascogne would have exploited "all-centerline" approach with only 3 150 mm triple turrets on centerline (2 superfiring each other and 380 mm TI fore, and 1 superfiring TII aft), best arrangement, with some topweight more. However, neither would have used 150 mm as a.a. guns anymore.

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Re: 150/152 mm gun turret locations

Post by spicmart »

Thank you, Hans. I will take a look asap.
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Re: 150/152 mm gun turret locations

Post by Herr Nilsson »

Although it was just a 6° wide sector (3°- 0°- 357°) technically Bismarck was able to fire 8 guns ahead at the same time.
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Marc

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hans zurbriggen
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Re: 150/152 mm gun turret locations

Post by hans zurbriggen »

Hello Mr.Nilsson,
thanks for this info. Looking at Koop-Schmolke plan (that confirms the slight angle inboard for the fore and center turrets, and also the aft ones) I noticed that I was wrong in my previous post: Bismarck will not be able to always fire 4 guns (mostly 6): apparently, center and fore turrets cannot bear much aft: there are 2 sectors aft that are covered only by one (aft) turret, thus 2 guns only. I estimate 30° per side the sector covered by 2 guns only, do you have the max angle for the center and fore turret when bearing aft (also the aft turret angle bearing fore would be interesting, of course) ?
Therefore, Bismarck was able to fire from 2 to 8 150 mm guns in one direction, Richelieu from 0 to 9. Bismarck has no blind sector anyway.

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Re: 150/152 mm gun turret locations

Post by Herr Nilsson »

hans zurbriggen wrote: Wed Sep 22, 2021 7:10 am ... do you have the max angle for the center and fore turret when bearing aft (also the aft turret angle bearing fore would be interesting, of course) ? ...
Schwenkwinkel.jpg
Schwenkwinkel.jpg (16.03 KiB) Viewed 1885 times
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Marc

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hans zurbriggen
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Re: 150/152 mm gun turret locations

Post by hans zurbriggen »

Hello Mr. Nilsson,
many thanks for this very valuable info. Therefore, if I am not mistaken with angles, Bismarck could fire 4 150 mm guns from 180° (directly astern) to 185°, 2 guns only from 186° to 210°, 6 guns from 210° to 330°, 4 guns from 331° to 356° and 8 guns for the last 3° (from 357° to 0° directly ahead) on Bb side, specular for Stb.

Do you know whether Tirpitz had different arcs for II turrets Bb & Stb, due to modified superstructure (first level) shape at center ship ?

hans
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Re: 150/152 mm gun turret locations

Post by Herr Nilsson »

The arcs for Tirpitz are the same.
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Marc

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hans zurbriggen
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Re: 150/152 mm gun turret locations

Post by hans zurbriggen »

Hello Mr.Nilsson,
thanks again.
hans
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hans zurbriggen
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Re: 150/152 mm gun turret locations

Post by hans zurbriggen »

Hello Mr. Nilsson,
I'm trying to build a graph with the firing arcs for "Bismarck"s.
Firing Arcs.jpg
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May I ask if you have also the exact firing angles for each 105 mm a.a. guns ? I guess here Tirpitz will have a slight advantage over Bismarck (due to her modified II turret position compared to sister), but I am uncertain a.a. arcs are meaningful, as possibly guns will have also bearing limits depending on elevation.
Many thanks in anticipation.

hans
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Herr Nilsson
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Re: 150/152 mm gun turret locations

Post by Herr Nilsson »

Bismarck:
Stb I 165°-357°
Stb II 15° - 170°
Stb III 7° - 170°
Stb IV 20° - 183°

Bb I 195°- 3°
Bb II 190°- 345°
Bb III 190°- 353°
Bb IV 177° - 340°


Tirpitz:
Stb I 165°-357°
Stb II 183° - 357°
Stb III 7° - 170°
Stb IV 20° - 183°

Bb I 195°- 3°
Bb II 177°- 3°
Bb III 190°- 353°
Bb IV 177° - 340°

That are the low angle firing arc figures. I have no information of high angle firing arcs. They could be different.
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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