Bismarck's protected depth

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George Gerolimatos
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Bismarck's protected depth

Post by George Gerolimatos »

Hello all,
I am trying to figure out Bismarck's vertical protection for a wargame. What I am interested in is the height of the ship's side above the water, her freeboard (amidships) I believe. I have found a figure of 5.7 m. Is this correct? I also have gotten conflicting measurements for her main (320 mm) and citadel (145 mm) belts. I have read on this site that the main belt was 5.2 m in height, but elsewhere I have read it to be 4.8 m. Finally, on this site it is stated that the amount of 320 mm armor above the water line was 2.8 m. If this is true, and the freeboard cited earlier (5.7 m) is accurate, then 2.9 m of Bismarck is protected by 145 mm armor, and below that, 320 mm for 2.8 m. Does this make sense? If my figures are accurate, then the much-vaunted statistic of Bismarck being protected by 320 mm for 70% of her length, though impressive, disguises the fact that shells that strike her side above the water line have a greater than 50% chance of hitting her rather weak 145 mm citadel belt! Uh oh...
George G.
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José M. Rico
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Post by José M. Rico »

Hello George,

The depth of the hull sides amidships from the upper deck to keel was 15 m.
The freeboard amidships varied from 4.8 to 5.67 m depending of the ship's draft.
The designed draught was 9.33 m; maximum 10.2 m.

9.33 + 5.67 = 15 m.
10.2 + 4.8 = 15 m.

The main 320 mm belt was about 4.8 m high (Breyer puts this figure at 5 m).
The height of the upper 145mm belt was 2.2 m.

Therefore the amount of 320 mm armour above the waterline varied from 3.5 to 2.6 m at maximum draught.

9.3 + 3.5 + 2.2 = 15 m.
10.2 + 2.6 + 2.2 = 15 m.

I will check the figures on the website again. I could have easily made a mistake.

I hope it helps,

José
George Gerolimatos
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thanks!

Post by George Gerolimatos »

Hello Mr. Rico,
Thank you for your help- I should have been more specific and stated that I am interested in the freeboard of the ship and the heights of the 320 mm and 145 mm belts at standard displacement-41,700 mt. I agree with the total height of the ship from keel to deck as 15 m, and that the max. draft is 10.2 m. Is the "designed draft" (9.33 m) the standard draft?
Thanks again.
regards,
George
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José M. Rico
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Post by José M. Rico »

Hello again,

9.33 m. is the construction draught (Tiefgang bei Konstruktionsverdrängung).

Breyer gives the figure of 8.7 m as the standard draught (Tiefgang bei Standardverdrängung) for a standard displacement of 42,958 tons.
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