The Best Torpedo Defense On a Battleship

all right hi I'm Ryan semanski curator for Battleship New Jersey museum and Memorial and today we've been doing our annual tank inspections which is why I'm dressed like this every year we go into or we go around to the sounding tubes there's well over 300 of them and sound them and see hey do we have any fluid in these tanks that we shouldn't like obviously some tanks have fluid in them that's part of our ballast system to keep us level most shouldn't but you know a pipe breaks inside of space like this or you get rain water coming into the ship deck train leaks or something and all of a sudden the water goes to the low spot and now it's in one of these tanks that you never get to so every now and again we find something um more often than not what we find is you know the sheet says that the sounding tube should be here but we can't find that or the um sounding tube is clogged broken will not open something like that so we can't actually sound that tank so a couple days every winter we go around and we actually climb down into those tanks that come up like we can't find where they are or the sounding says there's water in them and we go and we visually inspect and make sure that that's not the case or there is something wrong with this let's take care of it which is why I'm dressed like that but being inside of these tanks today made me think about what is good torpedo defense um and that is really where battleships are most vulnerable below the water line from day one until the end of their careers that is the part of the ship that is most vulnerable so obviously that is something that just about every nation did studies into and just about everyone came to the same conclusions but nobody actually built a ship with perfect uh torpedo protection so why is that so that's what we're going to talk about in this video we're going to talk about what everybody came to the conclusion of as being the most effective systems and why they then went and did something completely different also right up front it's worth pointing out that this is true for World War II era Torpedoes World War One era Torpedoes like that first half of the 20th century when battleships are really hot business as opposed to modern day Torpedoes a World War II torpedo slams into the side of the ship and explodes and rips a hole in the side of the ship and floods that way so this type of torpedo defense is specifically designed for that modern ships do not would not have much use for this it still protects against minds but in general a modern torpedo is designed to go under your ship and detonate there and the explosion displaces a bunch of water and that is going to push up on the bottom of your ship and bend your Keel that way and then when that explosion dissipates well holy cow now there's a cavity in the ocean where that explosion has pushed all the water away so now your keel drops back down to that point and it's supposed to break the back of your ship as far as I know there isn't really a good defense against that I think the submarine before it shoots at you um the Iowa class battleships don't really have anything like this we've got layered protection in case there is a physical explosion against the side of the ship but we don't really have any defense against the Keel being broken and so far as I know it would be classified if it existed but so far as I know there isn't any sort of special Keel design that protects against this type of torpedo so there were four principles and as early as 1906 when HMS Dreadnought herself comes out different countries like Germany Japan the United States Great Britain are all starting to do tests in fact Germany does some of the earliest tests with their pre-dreadnought type battleships and and whatnot to see well what will make an effective for Peter defense and the four rules that they come up with is you want your torpedo bulkhead as far from the explosion as possible so the explosion is going to be against the shell plating the outside of the ship so the deeper your torpedo defense can be the better that gives you a lot of room for that explosion to dissipate and so if it's got room to dissipate then it's not pushing all of its Force against this bulkhead right here the holding bulk had the innermost bulkhead where if that gets defeated now you've got water in the part of the boat where the people are which is decidedly a bad thing that's what we're trying to stop here so that's rule one the the deeper you can make that the better and so all other things being equal no matter how complex your torpedo defense system is if it is a shallow system it's not going to be as good as the guy who goes out there with a really deep system number two if you have a multi-bulkhead system and just about everybody went with a multi-bulkhead system you want the heaviest bulkhead inboard you don't want the heaviest bulkhead outboard one if the heavy bulkhead is is outboard that full explosion is being directed against that heavy bulkhead which means it's more likely once it's punched through that to then be able to act upon the lighter inner bulkhead and damage that two your heavy outer bulkhead is not going to be the same thickness all the way through battleships have armored belts those armored belts tend to terminate right around the water line where Torpedoes hit and an armored belt is capable of resisting most torpedo explosions however the significantly thinner steel below that will just rip away on that seam where it's mounted to the armored belt so you'll often see pictures where hey belt's perfectly fine or maybe it's indented a little but then below that it's all crumpled and hold and well I can see where the water got into that ship there's your problem so your heavy bulkhead should be inside if possible and as far away from the point of impact as you can make it the next rule of thumb is true of all armor not just torpedo defense one thick plate is better than multiple thin plates so if your torpedo defense is just one plate or really shell plating and then a gap and then one holding bulkhead and that holding bulkhead is thick you're going to have a better torpedo defense than the guy who has even 10 uh thin plates protecting them and our final rule of thumb is for your inner bulkhead your main holding bulkhead the load carrying capability should be in the plating itself the flat plating and not in the framing you do not want rigid framing because let's say an explosion comes into this space this Frame is probably going to hold tight but it's going to shunt that explosion on either side of this Frame so you see we've got a frame Bay here it's four feet wide because that's frame spacing on a battleship so you're going to see this wall here Bend IN in that four foot Gap and because it is in such a small area you've got more force on a smaller area it's more likely to tear and be defeated whereas if we're talking about this whole wall and the explosion comes through here and it's able to bend the whole wall away then it will have enough tensile strength spreading the force out along a great enough area that the whole thing will bend instead of breaking uh so that's part of why I O class battleships have this framing here it's helped pulling up this bulkhead but if this deforms if the holding Blockhead deforms it's going to rip away from this Frame as opposed to if this Frame was on the other side of the wall like you would expect it to be this should be on the inside of the ship not the outside of the ship Where We Are that would hold this wall and shunt things into certain pockets as opposed to yeah the wall will rip away from this as all one big piece so those are your four rules during the inner War period now everybody's got a bunch of extra ships to test on because the Washington Naval treaty says you have to dispose of them so some countries like the United States and Japan have almost brand new Battleship Halls that they're not allowed to complete Washington tosa some countries like the United States and Great Britain have German battleships that they've captured that they can do tests on uh some countries have older pre-dreadnought and Dreadnought type battleships that they're able to do tests on so they start to figure out how well their systems work and come up with formulas and whatnot and the Japanese come up with your biggest threat from a torpedo explosion is the explosion is going to turn the outer wall into shrapnel right explosion against metal makes a bunch of small metal pieces those metal pieces are what are going to punch through your inner wall and allow flooding inside the ship so you need something to stop those so the Japanese found out that uh exactly 600 millimeters about 24 inches is the perfect amount to have a void space it's about two feet and you fill that with liquid fuel water whatever and that is just enough that any Splinter that explosion happens out here punches into this space two feet of liquid will stop that splinter before it hits the inner bulkhead and punches into the rest of the ship if you make it deeper than that you're not getting any extra benefit if you're making it narrower than that it's not enough liquid to stop the projectiles created by this explosion so it might go through both bulkheads so your perfect torpedo defense is going to be a system as deep as humanly possible and that depth is going to depend on the size of the Warhead you're expecting to face obviously if somebody develops a bigger Warhead you're going to need more depth as opposed to a smaller Warhead where you don't need to be that deep and then have a single layer of fuel that's about 24 inches thick and that's all you need like I said nobody actually does this people come up with really complex things like puglies cylinders or crushing tubes like HMS Hood had or other sorts of things to try and absorb this explosion and why didn't they just adopt that well these ships need to carry enough fuel to get the range that they're supposed to have so for example New Jersey needs a range of 15 000 nautical miles of 15 knots which is 2.4 million gallons of fuel there is not enough room if you just have a 24 inch tank to carry all of that fuel so they have to add more fuel tanks the other issue you've got other things like the size of your slip Blade the size of your dry docks the size of your canals the Panama Canal the kilo Canal the Suez Canal things like this that limit where you can deploy your ships and this is limiting how wide you can make your ships so if your ship can only be 108 feet wide like an Iowa class Battleship and you need a certain amount of space in the middle for the engines and for the people and everything else well that only leaves a certain amount of space on each side so you cannot make it as deep as the math tells you you should and so the solution to that is to make as many uh Liars as possible theoretically the Iowa class battleships hold their fuel in the wrong spaces they should be holding them more interior that's what they were designed to do but they found that the torpedo defense system didn't work it wasn't deep enough so they moved the fuel to the outer tanks which were wider so those are the voids they're supposed to absorb more stuff but then there's more liquid to absorb the explosion so it's a little bit of a help and part of that is because by the time we get into World War II we're no longer doing these tests that we did in the teens and 20s and 30s we're just we got to turn these ships out to go and fight in the war uh so it wasn't until the South Dakotas were built the Iowa's were under construction already designed that they actually get around to case on tests of the torpedo defense and figure out this isn't as good as it should be so people try to come up with better Solutions and uh probably I've always said that the American solution of multi-layered system of Tanks with liquid loaded tanks in the middle and voids on each side is the best other people can dispute that but none of it is the actual best that you could do it's the best that you can do within the design constraints of these ships and maybe we would have found a way to do it better but Torpedoes changed and so torpedo defense is completely different nowadays so uh who do you think had the best torpedo defense or who do you think came closest to the ideal torpedo defense um you guys know I'm no fan of Bismarck but bismarck's main torpedo defense thing was just here's a big wide open space on the side of the ship and she was less restricted in beam than other ships she is wider than an hour-class Battleship despite being shorter so that's my guess what do you guys think let us know in the comments section down below Battleship New Jersey receives operating support from the New Jersey Department of State also from a number of other businesses and private individuals like yourselves we really 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Channel: Battleship New Jersey

Views: 99,083

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Id: vzjPncAIEAc

Length: 15min 52sec (952 seconds)

Published: Mon Feb 06 2023