USS Missouri armor questions

[Rick DeBay]

I have a few questions based on the plans at http://www.ussmissouri.org/missouri.pdf

The drawings show the splinter deck stopping at turret 2, so the space between turret 1 and 2 is not covered. Deck 3 between the two turrets is the sick bay and operating room. Was it not possible to protect the sick bay from splinters, or was it considered extremely unlikely that a shell could fall between the two turrets when they were turned broadside?

Did the 16" powder magazines have any additional protection from a blast that occurred below the armor deck?

What portions were constructed with mild, high tensile, and special treatment steel (excluding armor)?

What changes were to be made between the Missouri and Kentucky designs, to handle deficiencies in the torpedo side protection system?

Thanks, Rick DeBay

[Rick DeBay]

On the USS Missouri, the conning station is protected by an enclosed bridge. The vision slits in the conn therefore don't need to be protected from weather, but I was surprised to see that there was no 'plug' of ballistic plastic or glass that could be placed in the slit. There was only a thin exterior cover that could be flipped over it, which wasn't needed for weather as it was enclosed by the bridge. Also, how would it be protected from a chemical attack?

[Rick DeBay]

In the upper right corner, you can see the 16" shells in flight from this six gun broadside. The concussion roils the water for quite a distance out from the ship.

http://www.history.navy.mil/photos/i...000/g47015.jpg

[RustyBattleship]

Originally Posted by Rick DeBay

On the USS Missouri, the conning station is protected by an enclosed bridge. The vision slits in the conn therefore don't need to be protected from weather, but I was surprised to see that there was no 'plug' of ballistic plastic or glass that could be placed in the slit. There was only a thin exterior cover that could be flipped over it, which wasn't needed for weather as it was enclosed by the bridge. Also, how would it be protected from a chemical attack?

Conning Station covers were not flipped but were cranked into position. They were not thick but were of heat treated glass to keep out flash from hits in that area.

New Jersey was missing hers even in 1968 and Admiral (then Captain) Schneider wanted something over them. We had the plans to make them but Type Desk never could get funding from NAVSEA for that.

I'll get to some more of your questions later but we are getting ready to go to a birthday dinner.

[Rick DeBay]

Thanks. For clarification, the reference to "...mild, high tensile, and special treatment steel..." is because I was curious as to how contained damage would be in the superstructure. I read that the USN was quite profligate with high-tensile and special-treatment steel in ship construction, where most navies would use standard construction steel for similar applications.

[RustyBattleship]

Originally Posted by Rick DeBay

Thanks. For clarification, the reference to "...mild, high tensile, and special treatment steel..." is because I was curious as to how contained damage would be in the superstructure. I read that the USN was quite profligate with high-tensile and special-treatment steel in ship construction, where most navies would use standard construction steel for similar applications.

Most of the hull plating on an Iowa class BB is HTS. The main exception are strakes M and N at waterline where they are 1 1/2" thick STS to act as a trigger plate for torpedos or even shell hits that low (Remember, the main armor belt is 3 bulkheads inboard of the shell).

The main deck is primarily STS for both armor and strength reasons. Otherwise most other structures that were not armor were built of standard A-36 steel commonly known as "Medium" or "Mild" steel then (later reclassified in the 80s as "Ordinary Strength" steel).

HTS was eventually deleted from the Naval construction system being replaced with Carbon Manganese (on the Spruance class and Ticonderoga class ships) and High Yield 80 kpsi (HY-80) steels.

For replacement of original STS however, (in critical areas such as main deck plating or shell plating), Naval specifications call for HY-100 to be the replacement steel. I had a large insert in the main decks of both the New Jersey and Missouri as well as some special tow line thimbels to be made of HY-100. With the submarine industry using up all HY-100 and HY-130 steels I had a heck of a time finding some plates (Hunters Point had some in archaic storage and I procured them post-haste before Ingalls knew they were there).

Since then even the HY steels have been replaced with High Strength Low Alloy (HSLA) steels (Kidd class).

As for your original question on the Splinter deck, it's main purpose was to protect all the main and auxiliary machinery spaces. On Iowa and New Jersey it is 5/8" thick STS and on Missouri and Wisconsin it is 3/4" STS. It's only 30" below the 2nd deck so was quite an adventure crawling through its maze of compartments trying to route new piping or wireways through it. Main machinery spaces started aft of Barbette II and the space in between was mostly crew compartments or store rooms until you got way down to the bottom where the powder magazines were.

That's it for now. I'm going to bed.

[Rick DeBay]

Originally Posted by RustyBattleship

Conning Station covers were not flipped but were cranked into position. They were not thick but were of heat treated glass to keep out flash from hits in that area.

I can see how this would work (once) for hits on the conning station. Was there any concern about contact fused hits on the enclosed bridge? I would think that would blow in the glass, adding to the debris entering the conn through the slits.

[Rick DeBay]

Thanks for the reply. I'm looking forward to reading about the main powder magazines and the torpedo side protection system improvements when you get the time.

Originally Posted by RustyBattleship

Most of the hull plating on an Iowa class BB is HTS. The main exception are strakes M and N at waterline where they are 1 1/2" thick STS to act as a trigger plate for torpedos or even shell hits that low (Remember, the main armor belt is 3 bulkheads inboard of the shell).

BTW, what is the height of these two strakes? Is it from the armor deck to the third deck? That's what it looks like from the diagram on battleship.org, but it's hard to pick out the strakes in the area that has been bolded.

[RustyBattleship]

Originally Posted by Rick DeBay

BTW, what is the height of these two strakes? Is it from the armor deck to the third deck? That's what it looks like from the diagram on battleship.org, but it's hard to pick out the strakes in the area that has been bolded.

I haven't seen the diagrams on the website you are studying. But it sounds like they are merely copies of the Booklet of General Plans. The Booklet shows where strakes M and N are but not their thickness. At that time that was classified.

Also it doesn't show the Class A armor bolted to torpedo bulkhead 3 because that also was classified, even for the Booklet that was classified as CONFIDENTIAL.

[Rick DeBay]

The page is at Iowa Class: Armor Protection and the image on the page is http://www.battleship.org/images/BN/armor5.jpg . The image is credited to Robert Sumrall, so I assume it's from one of his books.

Come to think of it, did you review Amazon.com: Iowa Class Battleships: Their Design, Weapons and Equipment on Amazon?

[RustyBattleship]

Originally Posted by Rick DeBay

The page is at Iowa Class: Armor Protection and the image on the page is http://www.battleship.org/images/BN/armor5.jpg . The image is credited to Robert Sumrall, so I assume it's from one of his books.

Come to think of it, did you review Amazon.com: Iowa Class Battleships: Their Design, Weapons and Equipment on Amazon?

Ah. Now I know what site you were reading. The Iowa Class Preservation Association of which I am a member and contributor. They still have to get around to the write-up I gave them on the real cause of the crack in barbette III of Missouri.

And yes, I did write a review on Sumrall's book. As well as Grazke, Stillwell and Friedman and Newhart. Are those books on my shelf? Silly question. Of course they are. Especially those autographed and sent to me by the authors.

[Rick DeBay]

Originally Posted by RustyBattleship

They still have to get around to the write-up I gave them...

I enjoyed the articles, including that one, that you wrote for other sites. Keep passing the torch.

[Rick DeBay]

Originally Posted by RustyBattleship

As for your original question on the Splinter deck, it's main purpose was to protect all the main and auxiliary machinery spaces...It's only 30" below the 2nd deck so was quite an adventure crawling through its maze of compartments trying to route new piping or wireways through it.

Was there any concern for these pipes or wires being affected by the spalling which the splinter deck was supposed to contain?

[RustyBattleship]

Originally Posted by Rick DeBay

Was there any concern for these pipes or wires being affected by the spalling which the splinter deck was supposed to contain?

Pipes and wireways can be replaced. Plus there are purposely built in redundant systems as back ups.

It was more important to protect the crews in the boiler rooms from spall. Additionally, the 2nd deck was built up of STS and Class B armor for two reasons. One is you can weld to it with 25-20 Stainless Steel Rod. Two is that it doesn't spall or crack easily as Class A face hardened armor might.

Which is also why the turret faces are Class B instead of Class A.

[Shipwreck]

Originally Posted by Rick DeBay

I have a few questions based on the plans at http://www.ussmissouri.org/missouri.pdf

The drawings show the splinter deck stopping at turret 2, so the space between turret 1 and 2 is not covered.

The splinter deck was 25-lb (0.625") STS and ran from Frame 79 (abaft of Turret #2) to Frame 156 (forward of Turret #3).

Besides its protective function, the splinter deck was also meant to provide a heat barrier between the propulsion machinery and the rest of the ship.

The splinter deck area was therefore ventilated with both supply and exhausts systems.

Originally Posted by Rick DeBay

Deck 3 between the two turrets is the sick bay and operating room. Was it not possible to protect the sick bay from splinters, or was it considered extremely unlikely that a shell could fall between the two turrets when they were turned broadside?

I don't remember there was any *operating room* in that specific area and I don't quite understand what you're exactly referring to.

Splinters hitting the sick bay would certainly be a very unfortunate situation for those in there, but it wouldn't jeopardize any of the ship's vitals.

Additionally, there was no need for a heat barrier in this specific area of the ship.

Originally Posted by Rick DeBay

Did the 16" powder magazines have any additional protection from a blast that occurred below the armor deck?

The 16" powder magazines were actually located below the third deck, i.e. more than 10 feet below the armor deck (= second deck) at Frame 66.

The third deck was 40-lb (1") STS from Frame 50 (forward of Turret #1) to Frame 82 1/2 (abaft of Turret #2) between BHD#3 and from Frame 151 (forward of Turret #3) to Frame 166 (abaft of Turret #3) between BHD#3, versus 20-lb to 25-lb (0.5" to 0.625") STS from Frame 82 1/2 to Frame 151.

The powder handling rooms were protected by the turret foundation bulkhead (or stool) which was 1.5" STS.