Rusty BB ques boston whaler battleship

[petsan]

Hey rusty or any others more knowledgeable in naval
matters, heres a question

in the rough drawing below is a cross section of iowas side protection scheme



what would happen if you filled the 2 side protection voids and or oil fuel filled voids with modern foam as in a RHIB or boston Whaler

would there be any advantage if the battleship side holed?
How many voids would have to be filled to keep her afloat?

I read that the QUOTE "battleship Richelieu used a water-exclusion material (a bouyant solid foam encapsulated in foil packets) in her outer compartment which was designed to eliminate excessive trims resulting from flooding (and which apparently worked as advertised)" UNQUOTE

Would modern high density foam filled into voids perform the same or better?

Any thoughts

Im writing a short BB fiction story and want to know feasability....
thanks
Pete

[RustyBattleship]

First off, a slight correction to your drawing is needed and there is a reason for it for your answer.

Torpedo bulkhead 3 (the one with a foot thick of Class A armor) does not continue at an angle above the 2nd deck. As a matter of fact, that's where it stops. BUT, on the same joint, a VERTICAL longitudinal bulkhead is built that houses the garbage grinder room, crew showers, crew berthing, and access to the manholes to the void spaces and fuel tanks under the 2nd deck.

Now, at 3rd deck level, the void space between the armored torpedo bhd 3 and Holding Bulkhead 4 are instantly grabbed up by the crew for storage rooms, offices, etc.

Technically, if foam filling were to be done (which was studied by the way and would only be a 10 to 15 lb density closed cell foam for flotation) those offices and storerooms should be filled also. And every MPA and ship's Captain wanted them for people use and not sealed off.

Also, there is another problem with foam. Even if it provides some resistance to sinking, when the ship comes in for repair it all has to be cut out to get at the damage for repair. On BOTH sides of the damaged bulkhead.

And it is a beast to cut out for a number of reasons. During our Pop Up Polaris and Poseidon missile tests we designed a sled that would ride a short distance on a track to simulate a moving submarine while firing a missile underwater. The sled was hollow and filled with foam. When I opened up a corner plug to check the foam, I tried "drilling" through it by constantly spearing it with a piece of pipe for a core sample. It was solid resin where it was in contact with the steel sides of the sled. It looked like like amber and was as hard as amber (no, I did not look for any mosquitoes in it as Jurassic Park hadn't been written yet).

Checking with the company that supplies the foam, they told us that all sides of any container must be above 65 degrees Farenheit, preferably 75 to 80 degrees so the foam will not gel back into resin. So, on a Battleship, heating up a void space the volume of my garage with gajillions of strip heaters on the opposite sides of the bulkheads was just way over budget and schedule.

So the whole idea was completely abandoned.

[petsan]

thanks rusty

Sorry bout the rough sketch

here how about this


what if the foam was not solid but something akin to the BB richleau packets

If the above Foam packet void fill was found to give a BB a better resistance to turning turtle wouldnt ---"offices and storerooms, every MPA and ship's Captain wanted them for people use and not sealed off"
---be overuled if even there was a chance to keep my ship right side up if we were holed

[maximusslade]

If I may chime in...as far as being holed, I might suspect that you have a GREATER chance of turning turtle if the voids were filled with foam due to the fact that if there is a hole/flooding on one side of the ship, I wouldnt thing you'd be able to counterflood effectively enough to keep from turning turtle since you cant flood in spaces full of foam.

[RustyBattleship]

Hmmm, I didn't think of the "Packet" idea. We would just use foam blocks just big enough to pass down through the 15" X 21" manholes. But they would have to be of a heavier density in order to support the weight of the men installing them as they got higher up into the space. If the density is too heavy, floatation value is diminished. Even more so when you deduct the foam blocks destroyed by the penetration of a weapon.

Also, the foam weighs 15 to 20 lbs per cubic foot and this will add to the draft of the ship. At full load they are now a shade over 36 feet. But that is only leaving 18 feet of freeboard and any more weight decreasing the freeboard can make certain projects (such as refueling at sea) too hazardous.

[maximusslade]

Also, the foam weighs 15 to 20 lbs per cubic foot and this will add to the draft of the ship. At full load they are now a shade over 36 feet. But that is only leaving 18 feet of freeboard and any more weight decreasing the freeboard can make certain projects (such as refueling at sea) too hazardous.

Not to mention that increasing draft also reduces the ARMORED FREEBOARD there fore negating the purpose of an armor belt.

[DocHayes]

Educate me... whats the point in having fuel/oil on the outer bulkheads of the ship? I would think they would be vulnerable to attack, but I also suspect they may have something to do with ballast, balance, or even blast absorption... tell me.

[Dreadnought]

Educate me... whats the point in having fuel/oil on the outer bulkheads of the ship? I would think they would be vulnerable to attack, but I also suspect they may have something to do with ballast, balance, or even blast absorption... tell me.

Doc,
It would be for ballast. The Iowas replaced spent fuel with sea water ballast. The outter tanks (2) are flooded with either fuel or seawater to enable them to absorb/deform the blast of a torpedo/torpedoes hit and keep the ship in ballast. The inner (2) tanks are left empty or void to be able to capture any shards left over from the explosion and then you have the armor plating which is her side belt or bulkhead #3 followed by the holding bulkhead on the ships extreme interior. Hope this helps.

In addition the RN were known to fill the "void spaces" with wooden pieces such as beams and other materials to help absorb the torpedoes impact/shards as well before it reached their armor belts.

One further, the Armored cruiser Olympia (AR9) docked here in Philadelphia utililized what is said to be corn husks to fill their void spaces in her day. It was thought that if the side plating of the hull was pierced the corn husks would expand due to being wet and add some measure or water resistance to the interior hull or clog the hole if you would. I dont know this for fact but I did read this in a report when they were doing "soundings" on her hull and was written that remains of those corn husks were found in the void spaces. This was written in the Philadelphia Inquirer. I can produce the date of the article if need be.

[DocHayes]

Thanks... makes perfect sense. I haven't been on a ship since my days on the Marlinespike... thanks

[Tiornu]

Olympia is a protected cruiser rather than an armored cruiser, but I doubt anyone cares. In her day, "cellulose" was commonly used as a water-exclusion material, though the exact type of cellulose varied from navy to navy (and probably from ship to ship). The British went as far as using steel cylinders in their warship bulges, a practice that had a short lifespan in the RN. I believe Hood went to her last days with her bulge tubes, but that was unique. Nevertheless, the Japanese picked up on it and made bulge tubes a standard feature in ships of heavy cruiser size and up. These are sometimes called crushing tubes, but their main function was to encase air (buoyancy) even after the bulge was ruptured. I guess we can relate this to the empty drums fitted by the British into some merchant-type hulls to provide resistance to underwater damage.
But the French were the only ones to persevere with the more traditional water exclusion for their battleships. It does not seem, therefore, to have presented any great advantage, in the eyes of contemporary designers.