Search found 83 matches

by hans zurbriggen
Thu May 28, 2020 7:50 am
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Mr. Mostlyharmless, point I had made is that merely adding a layer of armour over another, does not add much extra protection (e.g. the tumb formula: multiple thicknesses of steel are equivalent to square root of the sum of the squared single thicknesses). Weak points (e.g. due to discontinuit...
by hans zurbriggen
Wed May 27, 2020 10:16 pm
Forum: The Dreadnought Era (1906-1921)
Topic: Kaiserliche Marine sailors quarters
Replies: 6
Views: 1161

Re: Kaiserliche Marine sailors quarters

Hello Marcelo, I do not have a confirmation for the fact that crew slept ashore during WWI. I have another 'negative confirmation': for their new battleships, German designers paid great attention to crew acomodation on board. During Bismarck design, it was even imagined to shorten the citadel belt ...
by hans zurbriggen
Tue May 26, 2020 8:03 pm
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello, I agree with Mr.Jurens consideration about structural elements and I would add that in case of Bismarck's, Nelson's and Littorio's (plus of course Nagato's), having also a third deck between the 2 armor decks, this adds thickness and other structural elements to be 'defeated'. Also, the subdi...
by hans zurbriggen
Tue May 26, 2020 12:38 pm
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello, to Mr.Dunmunro writing: ". ..your stubbornness in refusing to acknowledge the totality of KGV's deck... " I am extremely disappointed to see these kind of personal comments, especially as I would have so much to say regarding the same attitude from your side. I have no problem admitting my mi...
by hans zurbriggen
Tue May 26, 2020 8:17 am
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Mr. Dunmunro, you write: " it states a Brinell value of 170 for 'D' steel. ": only for post WWII D steel, not KGV one. and: " ...compares very well with the average nickel-steel armour given in the same table ": table refers to 1890-1925 steels (WWI), not the nichel-chrome-molibdenum WWII (e.g...
by hans zurbriggen
Mon May 25, 2020 9:52 pm
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Mr.Dunmunro, I am afraid I have given you the values of tensile strength demonstrating that D steel cannot be considered even close to an armor grade steel, the same concept Mr.Wahl explained to you. ST52 steel (the one used for mere hull plating of Bismarck) had hardness of 150 Brinell and te...
by hans zurbriggen
Mon May 25, 2020 10:57 am
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello, to Mr. Dunmunro writing: " .0805 calibre plate thickness begin to be effective for decapping at high obliquity" Another interesting aspect on which we can agree to disagree: it surely depends on obliquity, but other sources speak of up to almost 0.2 calibers to get de-capping at 90° impact an...
by hans zurbriggen
Mon May 25, 2020 7:33 am
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Mr.Dunmunro, "D steel was armour grade": here we can agree to disagree. It may have been used by some Navies for protection in some schemes (mostly when better steel was unavailable and/or only as splinter protection) but it does not have hardness and tensile strength quality (see the data I h...
by hans zurbriggen
Sun May 24, 2020 1:17 pm
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Mr.Dunmunro, D steel is a naval construction steel, not an armor grade steel, having hardness and tensile strength (around 50 kg/square mm) inferior to armor grade ones (e.g. German Wh n/A (85 kg/square mm), not even comparable to Ww n/A (70 kg/square mm), used for torpedo bulkhead and spliter...
by hans zurbriggen
Sun May 24, 2020 7:43 am
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Mr.Dunmunro, KGV non armor grade steel layers (or construction steel over which armor deck is simply posed) are not counted for protection effectiveness, not being able to de-cap an APC shell and not adding any protection against an intact shell body. I do not know if SD and Iowa 38 mm weather...
by hans zurbriggen
Sat May 23, 2020 10:19 pm
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello Marcelo, I agree, very difficult to get to synthesis of the scheme. This is common to many WWI era battleships: Hood is even more complex, with a quite thick "sum of decks" (not armor grade steel) but a very poor efficiency. Key point (that is valid for all values mentioned) is that thickness ...
by hans zurbriggen
Sat May 23, 2020 6:38 pm
Forum: Naval Technology
Topic: Nagato protection
Replies: 38
Views: 1216

Re: Nagato protection

Hello, to Marcelo Malara writing: "What surprises me is the thickness of the horizontal protection". I do not know if values reported are correct. My notes (unfrotunately I don't have the source) say: 1) weather deck in total 25 mm 2) upper armor deck 25+25+19 and 3) lower armor deck 51 mm total ove...
by hans zurbriggen
Tue Apr 21, 2020 12:59 pm
Forum: Bismarck General Discussion
Topic: Comment on Rebuilt US Battleships
Replies: 13
Views: 595

Re: Comment on Rebuilt US Battleships

Hello Mr.RobertsonN, I 100% agree: requirements for TDS were quickly evolving but Germans provided increasing TDS width from 4.7 (Scharnhorsts) to 5.5 meters (Bismarcks). Was it enough ? Difficult to say. Requirements for 6 meters width were recommendations: I remember the Scharhorst belt was initia...
by hans zurbriggen
Tue Apr 21, 2020 7:54 am
Forum: Bismarck General Discussion
Topic: Comment on Rebuilt US Battleships
Replies: 13
Views: 595

Re: Comment on Rebuilt US Battleships

Hello Mr.RobertsonN, I agree both layouts had their pros and cons. However Scharnhorsts had no additional TDS layer compared to Bismarcks. The 'wing compts' were 100% vital compartments (boiler auxiliary machinery and electrical plants), not intended to provide additional defense to boiler rooms. Bo...
by hans zurbriggen
Mon Apr 20, 2020 9:21 pm
Forum: Bismarck General Discussion
Topic: Comment on Rebuilt US Battleships
Replies: 13
Views: 595

Re: Comment on Rebuilt US Battleships

Hello, to RobertsonN writing: "The 14 in hit on Bismarck from POW that went under the belt would probably not have flooded a boiler room but just the wing compartment." not sure of this: according to survivors, PoW hit exploded against the 45mm Ww torpedo bulkhead (5.5 meters TDS wide). On Scharnhor...