Bismarck 'Gürtel' Construction

Discussions about the history of the ship, technical details, etc.

Moderator: Bill Jurens

hans zurbriggen
Senior Member
Posts: 279
Joined: Sat Dec 21, 2019 8:15 am

Bismarck 'Gürtel' Construction

Post by hans zurbriggen »

Hello,
does anybody know how many 320 mm KC n/A plates per side were present in Bismarck main belt? Were they all the same length or different?
I have found drawings of armored deck/slope, torpedo bulkhead and hull platings for 'Bismarcks' but not a single one for belt.
Looking at slope plates, I would say 43 per side (of different lengths), but it is just my poor guess.
Thanks for any help.

hans
Bill Jurens
Moderator
Posts: 838
Joined: Mon Oct 18, 2004 4:21 am
Location: USA

Re: Bismarck 'Gürtel' Construction

Post by Bill Jurens »

The precise arrangement is quite complex, particularly as some plates were subject to double curvature due the requirements to match the shell profile, and one is therefore fighting with what amounts to a plate expansion. Basically, my documentation suggests that there were 54 plates in the lower belt, spread over a length of about 171 meters, which gives an average width of about 3.16 meters. (The plate width varied a bit from plate to plate, depending upon location. Establishing and enumerating the dimensions of each plate individually represents a fairly complicated task which would appear to be of little practical value. As an aside, there were 30 plates in the upper belt, and these upper plating vertical joint lines have been particularly useful in establishing fairly precise locations for hits on the upper belt. This has not, as yet, been, been formally mapped, although we do have the imagery to complete such a survey should be of any practical utility.

Bill Jurens
Bill Jurens
Moderator
Posts: 838
Joined: Mon Oct 18, 2004 4:21 am
Location: USA

Re: Bismarck 'Gürtel' Construction

Post by Bill Jurens »

I just realized that I may not have actually answered your actual question, which had to do with the length of the plates rather than their width. The length of the plates along the surface varied from place to place due to hull curvature. At the ends of the armored box, the plates seem to have been around 5.5 meters long. Around midships, the lengths seem to have shrunk to a minimum of around 4.75 meters, measured along the curve. Assuming, for simplicity, that the curvature was a simple arc, the actual lengths measured across the chord would, of course, be slightly less than this.

Bill Jurens
Thorsten Wahl
Senior Member
Posts: 837
Joined: Mon Apr 27, 2009 4:17 pm

Re: Bismarck 'Gürtel' Construction

Post by Thorsten Wahl »

All plates were individually fitted to the ships hull.
depending on the hull shape at each plate had individual dimensions
sample

plate at frame 43.15m
width above 3312 mm (320 mm thickness)
width below 3322 mm (170 mm thickness)
lenght left side seen from inside 5209 mm
lenght right side seen from inside 5164 mm
inclination about 12 °

plates on starboard and port sides were mirror image

in general width ranges are from 2900 - 3300
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!
hans zurbriggen
Senior Member
Posts: 279
Joined: Sat Dec 21, 2019 8:15 am

Re: Bismarck 'Gürtel' Construction

Post by hans zurbriggen »

Hello Mr. Jurens,
thanks very much. I actually meant width, but length as well is interesting, sorry for my bad wording. I was interested to the plates number (54), and I now realize that slope plates were 43, lower belt were 54 and upper belt were 30 (per side).
Not being naval engineer I was thinking that same number/width of plates would have been better for solidity reasons, allowing to use exactly the same backing (reinforced) frame for supporting joints, but I was obviously wrong.

Hello Mr. Wahl,
thanks very much. I had never realized, lacking naval construction skill, that shapes could be so complex but I see now.
While I can understand why plate length aft is more that fore (at frame 43.15, due to more bending aft), I am a bit surprised about width above being less than below: I could have expected vice versa. :think:

hans
User avatar
Herr Nilsson
Senior Member
Posts: 1531
Joined: Thu Oct 21, 2004 11:19 am
Location: Germany

Re: Bismarck 'Gürtel' Construction

Post by Herr Nilsson »

Plates 1-54 main belt, plates 55-84 upper belt. The main belt plates were roughly twice as heavy as the upper belt plates.
Seitenpanzer.jpg
Seitenpanzer.jpg (45.14 KiB) Viewed 1469 times
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
hans zurbriggen
Senior Member
Posts: 279
Joined: Sat Dec 21, 2019 8:15 am

Re: Bismarck 'Gürtel' Construction

Post by hans zurbriggen »

Hello Mr. Nilsson,
many thanks. Is your document available at any public archive ? What is its number/name ?

hans
User avatar
Herr Nilsson
Senior Member
Posts: 1531
Joined: Thu Oct 21, 2004 11:19 am
Location: Germany

Re: Bismarck 'Gürtel' Construction

Post by Herr Nilsson »

No. Gewichtsliste S.
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
Steve Crandell
Senior Member
Posts: 873
Joined: Wed Feb 05, 2014 7:05 pm

Re: Bismarck 'Gürtel' Construction

Post by Steve Crandell »

Some of these things desperately need to be digitized so they aren't lost forever.
Bill Jurens
Moderator
Posts: 838
Joined: Mon Oct 18, 2004 4:21 am
Location: USA

Re: Bismarck 'Gürtel' Construction

Post by Bill Jurens »

My gratitude and thanks to correspondents who have taken the time to elaborate, and greatly enhance, my initial reply to this thread.
This additional detailed data may be revealing, at least to me. Few other nations went (or probably would have gone) to the trouble to fit things so perfectly to geometric circumstance, i.e. most other nations did indeed make all of the belt plates m0re-or-less the same, at the cost of some sacrifice in geometric elegance.

I wonder if this tendency also reflects upon the previous discussions surrounding the slight taper that was installed on the various barbette arrangements as well, i.e. reflects a tendency to simply 'do things right' rather than do things most efficiently; the latter representing a philosophical tendency probably more at home in the U.S. and Britain than elsewhere.

Alternatively, this may reflect a feeling that once the infrastructure to manufacture armor plates of this size was in place, and production quantity was limited, that rather than leave these expensive facilities under-used, it effectively represented little or no excessive extra expenditure to produce a small number of relatively complex plates rather than a somewhat larger number of plates of similar or identical geometry, which is probably more along the lines of British or American manufacturing.

Perhaps I've got this entirely, or at least partially, wrong. Comments, as always, very welcome indeed.

Bill Jurens
User avatar
marcelo_malara
Senior Member
Posts: 1454
Joined: Sun Oct 02, 2005 11:14 pm
Location: buenos aires

Re: Bismarck 'Gürtel' Construction

Post by marcelo_malara »

Steve Crandell wrote: Mon Jan 24, 2022 9:35 pm Some of these things desperately need to be digitized so they aren't lost forever.
Agree with this, may they be added to a documentation section in the site?

Regards
Post Reply