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Question on longitudinal STS bulkheads inside Iowas turrets

Posted: Thu Aug 15, 2013 11:45 am
by petsan
On 19 April 1989 inside one of the USS Iowa's 16" gun barrels, five 55 or 100 pound bags of D-846 powder blew up, a fireball 3,000°F with a pressure of 4,000 PSI blew out from the center gun's open breech, the explosion caved in the door between the center gun room and the turret officer's booth and buckled the bulkheads separating the center gun room from the left and right gun rooms, the fireball spread through all three gun rooms......

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Does anyone know the actual thickness of the STS longitudinal bulkheads between the individual gun chambers (in red) and or the transverse bulkhead forward of the turret officer's booth (in green)?

I read somewhere, maybe on another BB class that the Longitudinal blkhds. were 4" STS, but I cant find it anywhere in my BB library....No luck with main Battleship Books Dulin,Friedman etc.
Thanks All in advance

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Fri Aug 16, 2013 6:47 am
by Thorsten Wahl
I think the cracks at the worldaffairsboard are better qualified to answer this question.

maybe ther is some information on
http://hnsa.org/doc/index.htm#guns

"Gun Mount And Turret Catalog, Ordnance Pamphlet 1112, 1945, is a Navy catalog of Gun Mounts and Turrets that includes almost all the U.S. Navy WW II equipment."

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Fri Aug 16, 2013 5:04 pm
by Bill Jurens
It's only my recollection to be sure, from looking at drawings some time ago, but for what it is worth...

The internal bulkheads in these turrets served both as structural supports to prevent downward deflection from projectile hits on the roof and to limit the spread of flash and flame if an internal explosion occurred. Each of these internal bulkheads is therefore really formed of two portions -- structural sections made up of deep girders and 'columns' of 40lb (or so) plate, and a collection of intermediate 'membranes' that were designed to confine internal explosions. These latter were, as I recall made of 20 lb plate. Around the deck lugs, the plates were thicker still, in order to support the guns. So, to answer your question of 'how thick?', one must first define exactly where you are looking.

The situation is complicated because some of the internal partitions were not ridgidly attached to the roof plates, this apparently in order to allow roof plates to be more easily removed in case internal repairs were required.

The diagram you presented by the way shows the explosion taking place much farther forward than it actually did.

Bill Jurens

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Fri Aug 16, 2013 9:25 pm
by petsan
Thanks Mr Jurens and everyone else

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Sat Aug 17, 2013 9:36 pm
by dunmunro
Bill Jurens wrote:It's only my recollection to be sure
Bill Jurens
Bill, hi. You might like to peruse this thread and share some thoughts:
viewtopic.php?f=9&t=5843

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Sun Aug 18, 2013 4:37 am
by Bill Jurens
Hello Mr. Munro:

I did take a quick glance at the thread you mentioned, but am not quite sure what is being argued about. Perhaps someone might clarify.

My only immediate comments would be:

a)There is really nothing new in the material being presented on Hood's testing, etc., as all of this has been in the public domain for years and years now.

b)I'd express my usual skepticism regarding the use of computer programs such asNAaB and FaceHard to obtain useful analytical data, especially when data is 'stacked', i.e. output data from one program is used as input data for a second one.

Bill Jurens

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Sun Aug 18, 2013 7:24 pm
by dunmunro
Bill Jurens wrote:Hello Mr. Munro:

I did take a quick glance at the thread you mentioned, but am not quite sure what is being argued about. Perhaps someone might clarify.

My only immediate comments would be:

a)There is really nothing new in the material being presented on Hood's testing, etc., as all of this has been in the public domain for years and years now.

b)I'd express my usual skepticism regarding the use of computer programs such asNAaB and FaceHard to obtain useful analytical data, especially when data is 'stacked', i.e. output data from one program is used as input data for a second one.

Bill Jurens
I may have seen this info earlier, but I was still surprised by the ability of the RN 15in to achieve such a degree of deck penetration. However I would suppose that a point of contention is that I see an analogue between Hood's armour scheme and Bismarck's/Scharnhorst's scheme.

sorry for bringing this threat OT.

Re: Question on longitudinal STS bulkheads inside Iowas turr

Posted: Sun Oct 13, 2013 4:12 pm
by sineatimorar
Talking about the explosion. Any comments on the lack flash-over protection in the ammo handling trunks? Most of the investigation reports lack in-depth cause and effect analysis.Reading the autopsy reports suggest while some personal were killed by what could be termed "blunt force trauma" from the shock wave generated by the blast front, a majority seemed to have been killed by effects of flash-over from the exploding powder charges in the handling room. By inference only as no actual mention of the blast path is actually ever mentioned, I can only come up with the ammo trunks been the transfer path from the gun room to the lower handling room. A case of simplicity over more complex interlock arrangements maybe.