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Re: HMS Hood's armour layout

Posted: Tue Feb 01, 2011 1:38 am
by Bgile
Tiornu wrote:Didn't Alaska also have gradations in her barbette armor?
I think this must be a feature restricted to new ships, at least as far as the Americans are concerned. I'm looking at Nevada, and her barbettes have the same thickness all around.
I wonder whether it required more advanced metallurgy or if it was more expensive.

Re: HMS Hood's armour layout

Posted: Tue Feb 01, 2011 8:56 am
by RobertsonN
One can also see this point in the transverse bulkheads.
Those of the Iowa were 11.3 in thick. According to Friedman in US battleships this was proof for battle ranges provided the ship was more than 50 deg from dead ahead of its oppenent (or within 40 deg from abeam). Even the mighty Yamato had quite heavily graded barbette armor. It was probably a question of mimization of risk to the ship taking into account its intended tactical use. It would not have made much sense to have the barbettes (the rear barbette is not shielded by anything on three turret ships and any shielding of B by A is very dependent on angle and range, the front of A is likewise unshielded) immune within that 50 deg sector when the bulkheads were not.

Re: HMS Hood's armour layout

Posted: Tue Feb 01, 2011 5:28 pm
by Bgile
True enough, and most battleships seem to be more vulnerable from the ends.

Re: HMS Hood's armour layout

Posted: Tue Feb 01, 2011 8:38 pm
by Tiornu
Yeah, I was thinking the same thing about bulkheads. If you look at Yamato's bulkheads, you can see the designers struggling to consider a wide range of bearings.

Re: HMS Hood's armour layout

Posted: Fri Oct 18, 2019 6:47 pm
by Ski206
I know this thread is rather old but hopefully I’ll get a response. In a post above a link is provided at admirals.org to a RN study of the immunity zones of their capital ships to the German 15”shell dated 1939. That link no longer works. Does anyone know where that paper can be found today?

Re: HMS Hood's armour layout

Posted: Thu Nov 07, 2019 1:00 pm
by Mostlyharmless
Ski206 wrote:
Fri Oct 18, 2019 6:47 pm
I know this thread is rather old but hopefully I’ll get a response. In a post above a link is provided at admirals.org to a RN study of the immunity zones of their capital ships to the German 15”shell dated 1939. That link no longer works. Does anyone know where that paper can be found today?
It seems to be available via the Internet Archive at https://web.archive.org/web/20180819100 ... 1-9387.php

Re: HMS Hood's armour layout

Posted: Fri Nov 22, 2019 8:09 am
by Thorsten Wahl
have a question
the british protection charts listed marylands deck armor as consisting of 5 1/2 inches of deck armor giving protection against ballistic attack up to about 27,000 yards.

as far as i know the deck protection consists of the
-second deck
laminate made of 60# STS over 60# NS
and
-splinter deck
laminate made of 40# STS over 20 # MS

these thicknesses are consistent with Bu-Ships memorandum report "battleship protection characteristics" from 1942 wich state that BB 48s deck protection offers a outer limi of immunity of 15,500 yards versus the 16" 2240 lb AP projectile fired at 2520 ft/s wich is equivalent to less than two inches of ballistic protection.

What appears as the source for the obvious wrong thicknesses the British used? "Jane's handbook"? systematic misinformation?
Thank you