The Best Torpedo Defense On a Battleship 

The best torpedo defense for WW2 is to ensure your opponent is using the Mark 14 Torpedo. Unfortunately, the Japanese had that.

Ryan's explanation of how a modern under keel explosion breaks the back of a warship is also a good description of how a depth charge sinks a submarine. The depth charge explosion creates a hole in the ocean that over flexes the hull of the submarine, even if the original explosion didn't impact it directly. The explosion will rebound in and out as it surfaces, so even if the depth was set too deep, it can still kill the submarine as it "floats by" towards the surface. In movies, the huge surface explosion is actually caused then the depth charge is set too shallow, and the initial explosion breaches the surface immediately. Looks cool, but wastes the power of the explosion.

The fact is for every person in charge of designing a better torpedo defense, there is someone else designing a better torpedo.

Former IJN admirals also said they were surprised at how easily USN torpedoes were defeating their TDS in the latter half of the war, and only after the war they realized that it was due to the USN upgrading the torpedo warheads with Torpex which contained aluminum that greatly magnified the power of the detonation.

USS Pennsylvania proved the best torpedo defense is to be in drydock when torps are in the water.

What was really notable was the number of WW1 battleships sunk by a single mine or torpedo. By WW2, ships were more survivable.

Drachinfel did a great piece on warship armor through the years. HOWEVER, it is nice to see inside Big J's armor.

A point Ryan’s explanation elided: not all armor is better with one thick plate as opposed to many small plates. This is specifically true with shaped charges, most often seen in anti-tank armaments. This is because the effectiveness of a shaped charge is based on the focal length of the charge, which functions like a magnifying glass does with sunlight but instead using an explosive to shape a slug of (usually) copper into a jet of hyper velocity molten metal. This can be defeated by having a sacrificial plate which detonates the shaped charge (much like how the New Jersey has an external shell plate intended to de-cap incoming shells causing them to detonate against the external armor before it penetrates) followed by heavier armor intended to defeat the dissipating jet of molten metal - often by sloping the interior armor as well, redirecting the dissipating jet.

Montana was not following the TDS used on both SoDak or Iowa. Montana was to use the tried and true TDS on North Carolina. While North Carolina TDS nearly failed, it DID hold while being hit at the weakest possible point on that system (by the forward most turret where the system is very narrow) by a weapon that exceeded its intended design parameters. Makes sense.

Drach just did a video today (Feb 8), of the torpedo hit on the North Carolina, interviewing a rear admiral, who's studied it. The North Carolina's defense, held up quite well, against a Japanese type 95 torpedo. The ship managed to stay a speed, and suffered little extra damage while at speed. That's more than you can say about the Bismarck suffering a smaller hit to its bow.

I like that you take an active role in maintaining our girl. Curators in most museums means a paper pusher, but you get grubby and enjoy doing it. I wish Mike Rowe still did dirty jobs, the Big J would be perfect for him.

“You sank my battleship!” - said no one ever assigned to an Iowa 😎

The enormous size of Yamato and Musashi would have to take the cake, even though the armor joint was their undoing. However, what other ship could take that punishment? As far as a more normal ship the French Richelieu class had the deepest protection, combined with the ebonite mousse that was packed it the voids. So I’d give the edge to them

This video gives a glimpse of how complex maintaining or mothballing a battleship is. Keeping one in action.....I can't get my head around it!

Love how he isnt afraid to get dirty.

Excellent episode! Thanks!

Another great video from the battleship. Keep it going

I remember someone saying 'can you imagine if a navy actually had the Bismark and Tirpitz at the same time? that would have been unstoppable!' and I was like yeah I can imagine. the US had 4 Iowa class battleships and each better than those 2 ships.

Great presentation

The British used the HMS Hood predecessor ship, a Royal Sovereign Class Pre-Dreadnought Battleship to test new torpedo defense system

That was another great episode thank you. I do have a question.What about doing an episode on how the recoil system on the 16in in 5-inch guns?

Not gonna lie, I glanced at the thumbnail, thought it was Drach, and only once it was a few minutes in I realized that this wasn't Drach's footage from his earlier or current US trip. Not that I regret clicking, very nice and informative video. :)

A related question is how do they protect their propellers and rudders? The mention of Bismarck brings this to mind, given it was a torpedo hit to the stern that doomed her.

Thank you, I enjoy your videos.

Your videos have gotten so good, keep it up, thx

South Dakota-class BBs probably had the best TD architecture. Their armor belt was inside the ship and sloped. It was continuous from the top of the citadel down to the double bottom and it did triple service - it was an armor belt, it was structure, and it also formed the torpedo bulkhead.

I would love to see good videos of the framing and welding. I have built a lot of aluminum boats and done a bit of steel shipbuilding and later moved into different types of land based construction. I found it really interesting how different code committee's ha e different views on what is ideal with some preferences being defective by another standard. I would find it interesting to see what the welding was like on a full warship when welding was still pretty new and what if anything has changed.

Ryan, I read somewhere that the science of steel making evolved considerably after WW-2. Not just in efficiency, but also in the strength and resilience of the material. Factor in also the use of plastic explosives, in reactive armor, as seen in tanks. If, you were given a cheque for $ 12 billion, to build a battleship today, what could you describe, in those terms, and also for the armament ? I realize that's somewhat of a project, but it maybe an interesting idea for a series,,,

The Hood's crushing tubes were probably a good idea in the 1920s but by the 1930s probably not but as far as I know, the British planned to remove the crush tubes and convert the space in the buoyancy space into fuel tanks Do anyone know what TDS the Renown and QE rebuild used?

Interesting, thank you

If you had to pick a ship it probably was the Yamato class BBs. The Yamato took close to a dozen torpedos and Musashi by almost 20. Size had its advantage for sure.

I think you need to look at two sides of the question: not only what anti-torpedo system the battleship had, but how big a warhead was launched against it. I think Yamato class BB's took the most hits before sinking, but they were hit by air launched torpedoes that were usually lighter than those carried by surface ships or submarines. In principle I like the idea of making a path to atmosphere for the expanding gases in the space between the side shell and the holding bulkhead. When I visited the Massachusetts I saw the row of inspection ports along the side slightly below the sheer and I thought that's what they were, but I wasn't able to confirm that in the sources.

Good lookouts and a fast hand on the wheel. Steer parallel to the torpedo track.

What's also interesting is that while between-war naval architects were trying to defend against side contact hits, torpedo designers were trying to perfect the underhull influence detonators that would have made the bulges useless. Obviously, the influence detonators have since been perfected.

I like the way the Iowa Class can vent all of its steam pressure in a short burst to leap out of the water and over any torpedoes.

The effectiveness of under the keel explosions was well understood by the interwar years. That is why the Royal Navy, the US Navy and the Kriegsmarine developed magnetic exploders, none of which worked. The Japanese went for a big warhead instead. The Yamato probably had the best designed torpedo defense system. However, it was apparently poorly built and prone to failure.

The Americans did have magnetic detonators for the Mark 14 torpedo. Unfortunately they only worked in Long Island Sound off of Connecticut where they were tested. Strangely enough, the Earth's magnetic field differed mightily elsewhere, especially in the South Pacific.

Visited your ship, shout out to the radio guys going ham!

Also, the problem with fuel, water, or ballast tanks is at some point they may be empty as fuel is used or ballast is shifted as needed.

7:04 This is also because of splinters. By having the outer layers made up of thin plating, any splinters created by a torpedo will be smaller and will be better resisted by the thicker, inner bulkhead.

You're definitely bringing up some good points. I've heard very little of how ships survive battles. Maybe you could start a series on what they do, closing doors, pumping, aux systems, fire fighting, intentionally flooding. Britain welded together a boat with a blown off bow with a ship with a missing stern. THAT IS A STORY!

the only real defense against modern torpedo is just sheer size. Be so big that the torp just does localized damage that you can accept and keep going. Maybe the WW2 pyecrete aircraft carrier that never got built would be able to deal with torpedos, not only accepting the damage, but being able to do actual self repair at sea. What if the US or UK built a battleship hull out of Pyecrete?

The best torpedo defense is a good screen of destroyers!

The best torpedo defense is not being hit.

My candidate for the best TDS would probably be that of the Nelson class (predicded to be proof agains an 800 pound warhead, shown in full scale testing to be proof against a 1000lb warhead). Technically speaking it should probably be that of the later ships which used a derivative of it, but I'm not entirely comfortable of the way that their armoured belts and deck encase the TDS (and there's also a fact that the lower edge of the belt is potentially a source of splinters if a torpedo hits higher than it would in normal conditions).

The best defense against torpedoes is not to get hit by one. Best way to achieve that is speed. This is especially effective where the submarine is diesel electric and the ship is a fast one. The faster the ship goes the more difficult it is for the sub to get into position for a firing solution and thus the Ship's Torpedo Danger Zone (TDZ) becomes close to her intended course. If the ship intends to remain in an area, the best thing to do is a constant circle with varying radius of turn. Almost impossible to get a firing solution.

Actually, almost any of the big Nations in World war 2 already had Torpedos with magnetic Detonators in somewhat wide use going into WW2. These Torpedos would detonate from the Magnetic Influence of a Ships Bow. so if you set them to the right depth (and current earth magnetic influence) they would detonate 1m / 3 Feet below the keel of your Target.

The best for armoured vehicles was plates with hex standoffs between them. It also adds structural strength without much weight. This would help with detonation from below also.

The French had a very interesting system for the Richelieu: they had four spaces, with the two innermost liquid loaded, the next space void, and the outer most was filled with a rubber foam. Now whether this foam could absorb the explosion's energy is up to debate (highly unlikely), but the French were more focused on the aftermath of the explosion. In essence, the rubber foam was there to reduce flooding by denying the water a space to fill, as well as acting as additional buoyancy. As the full size system was never hit with a torpedo we unfortunately don't know how well it would have worked at stopping one, but it does rate favorably in post hit damage control.

Nice big layer of squishy foam on the outside so torps just bounce off harmlessly! 😁

HMS Nelson & Rodney circa 192/30's used i for torpedo protection, Stephennternal water

You should schedule that tank crawl when Drac from the UK comes back!

The old USS America and the Nimitz class supposedly have, in addition to the usual transverse water tight bulkheads, there are two full length longitudinal water tight bulkheads that run from the main deck, which is the hanger deck on American aircraft carriers, all the way down to the bottom of the hull. Aside from giving the ships exceptional compartmentation these would seem to stiffen the ship significantly against torpedoes exploding under the ship and perhaps prevent her back from being broken.

I like this guy👍

Many of the newest torpedoes are using shaped charges to create a super heated explosion that burns through the hull, really only the US Mark 48 is still a keel breaker, that way they can use the new light weight torpedoes.

German and US (Mark 14) torpedos were also designed to be set to pass below ships and explode underneath, as you explain is true for modern torpedos. Unfortunately, the magnetic pistols of both country's torpedos were unreliable. The Germans (as I understand it) had reliable contact pistols but of course the Mark 14 did not, a double whammy. But the principle was understood back in the 1930s. The magnetic mines used by the Germans had the same effect and led to the large-scale demagnetizing efforts by the Brits and Yanks.

As to the bismarck, it's hard to put avoid space around a rudder. Fortunately you are with flying those swordfishes seemed to know that.

Not sure of the real world practicality of it, but some kind of layer of crushable material, foam or something, under the keel, that would absorb the initial blast. That combined with clever design meant to absorb some flex, and support 'unsupported' sections. Not sure if/how it would work, but my brain also conjure the image of just blasting a ton of air under the section of the ship before the torpedo detonates. If it were blasted down in very high pressure jets, it might somehow disrupt the blast wave, or maybe do nothing, who knows. Or, realistically, some form of mini anti-torpedo torpedo to detonate it too soon.

For modern torpedoes maybe a triangulated keel beam would work better then the "I" beam conventionally used, would be cool to see some testing on different designs.

Friedman came to the conclusion that the rebuilt American Standards had the best actual WWII torpedo defense systems, especially after analysis of the faulty lower belt attachment design of the Yamatos AND the SoDaks and Iowas.

I suppose you could always have voids/compartments under the keel of a modern ship, to absorb the explosion of a modern torpedo. But they would have to be extremely strong to support the weight of the ship during dry dock. And I'm not sure if that would help with the second part, where there is suddenly a large air pocket under the ship after the explosion.

Hedgehog depth charges

The idea of 1 thick plate being better than multiple thinner plates, even if the thinner plates are equal or thicker than the singular plate is interesting. Because we see the opposite wisdom in tank armor. Tank armor will often favor air spaces between layers of relatively thinner armor. This helps mitigate HESH and HEAT rounds and CAN have some effect against sabot penetrators. I'm not speaking of slat/cage armor. I can only guess that some of the fundamental assumptions in naval armor are different from those of tank armor. That or the difference in degree is so great that it may as well be a difference in kind.

Hmm you know something about Swedish navy stuff? would love to hear about those bc of the U-boat history

The protection against modern torpedoes is actually having multiple layers of hull, this is observed when ships are called "double hulled" or etc, the reason you don't see it often however is that you're now requiring just shy of double the resources for your hull or more depending on how many layers you add on top of reducing your usable interior space which is a premium in ships due to size constraints being limited by using the Panama Canal for convenience.

How about working with Drachinfinel on how an Iowa would've dealt with a hit similar to a Fritz X?

Best one is the one that keeps the water out of the people tank.

I think it's great that the Navy gave an entire battleship to a homeless guy.

Is this the new pre stream intro? As you should keep it

He explains things in a way that is completely non-understandable to me. This is a first for me.

UK in WW1 had torpedo bulges that slowed ships but seemed to work well enough. So Lord Clive class monitor would be an option if very slow. There were also stories of Japanese convoy decoy ships that had minimum draft and were at least partly filled with ping pong balls or other light and Bryant filler. No idea if these really existed.

I'd say the Zeppelin had the best torpedo defense system, staying well out of the water. But it was vulnerable to other attacks. 😁

A honeycomb ribbed Keel designs can overcome modern torpedoes.

Only two modern battleships come to mind with a single torpedo hit that allowed the results and damage to be investigated that I can think of. IJN Yamato and USS North Carolina. With Yamato, they realized that their torpedo bulkhead backing was too rigid and the braces punched through the torpedo bulkhead and caused way more flooding than they expected. The North Carolina's system worked well even though it was hit in one of its shallowest sections. The place where it was hit was even noted by designers as a problem spot. So I'm thinking the American system was one of the best even thought, due to the width of the Panama canal, they couldn't make it deep enough due to ship beam restrictions.

The Iowa has 13" hardened steel belt armor with 4" more in a double shell hull. If it made it through that. 17" hardened steel pilot house with a periscope. Clear, red, and yellow, lenses.

With the enlargement of the Panama Canal, at least that's no longer the bottleneck that it used to be.

I have an awesome idea for torpedo but i have never had anyone to tell about it

Ryan finally with some love for the Bismarck! Eventually you’ll come over to the dark side and be a Bismarck lover.

As below, best defense is not to get hit by a torpedo. Therefore today the key is detection of the torpedo and the means to eliminate as far from your ship as possible. Explosions in water lose their effectiveness over distance, so the farther away the torpedo explodes the better. Passive ways is Nixie (trail a steel cable that is able to mask the ship, or create more noise, or electronic countermeasures). Active could be a smaller torpedo used to hunt the incoming torpedo. Another would be similar to the old hedgehog (sub countermeasure for U-boats from WW2), except in this case would drop down over an area the torpedo would come into (again the farther from the ship as possible). A third measure is the construction of the ship itself. Most of the weight of the ship lies or is attached to the keel, break the keel, break/sink the ship. In drydock the ship lies on the keel to support the weight of the ship. So what could you use to strengthen the ship construction to support the weight of the ship when water doesn't support its weight. Torsional decks that resist bending (torsion boxes). These decks would have to be long at least 2-3 X explosion diameter (also supported by torsional bulkheads longitudinally min 4 to provide a very stiff box). A suspension bridge has stay cables under tension, to hold the weight of the bridge decks on suspension bridges. The problem with this is the anchor has to be supported by water (the support is not undermined by the explosion). On a battleship the fwd and aft armor bulkheads could be used as anchors (towers on suspension bridges). Also below someone mention venting the explosion to the surface. Probably not practical due to the explosive amount of gases, but I like the idea of "path of least resistance" of the explosion to follow. This could possibly screw up the secondary effect of a torpedo explosion.

I was wondering, if you want the best torpedo defense on a ship that you're building against, say, type 93 (the most op of torpedoes), then why not take the best features from each nation's ships & mix-&-match which is the best configuration? Or combine all of them outright? I'm talking about the WW2 timeline here

5:21 A significant emotional event as it were

Kitty Hawk Class carriers. Because they were not constrained by the Panama Canal size they were designed with the multilayered void system. At the time of their launch, it was expected to be effective against the torpedoes in existence at the time.

So in other words, letting one of the screening destroyers or cruisers take the torpedo hit is best?

What are your thoughts on Yamato class torp defense?

Why is such a large (arguably important) overhead conduit located in a space which was essentially designed to be expendable? I mean not that they PLAN on getting hit there, but is all that wiring just for stuff outside of the main belt and they have to collect it and run through one area? That might be an interesting video actually, are there any locations where something was built through the full thickness of the main armor belt?

Was there any way to spot and destroy an incoming torpedo ?

Side pontons with net hanging down the depth of the ship would be a good defense. Dunno how much it would slow down the ship though.

The British had a good wide blister on a few of their refits and monitors.

We were told on our FFG our main mission was ASW # 2 was escorting battle groups We were to intercept torpedoes with our hull

The Iowa had the best system against mag torps a triple bottom and a huge keel

Would multi-hull designs help with modern torpedoes? Or putting a hull or multiple hulls within a hull? Or maybe put your ships on hydrofoils? Or maybe we need anti-torpedo torpedoes, perhaps using small, rocket-propelled, super-cavitating point-defense torps.

Considering the amount of punishment that Bismarck took and stayed afloat, until her crew scuttled her, I'd say her armor was more than adequate to keep torpedoes from penetrating her hull. I remember seeing a show that featured Bismarck, and an ROV proved that the claimed British torpedo kill shot had penetrated the outer hull but the inner hull was still intact.

Would the defensive properties of the liquid filled spaces vary significantly depending on the properties of that liquid? i.e. salinity, viscosity, density, etc.. As in, would fuel be better than seawater (or was fuel worse, but you needed it along anyway)?

I love the massive torpedo defences of the WWI monitors. They couldn't move fast, as they were mainly anchored up doing shore bombardment, so were really vulnerable to submarines. They also didn't have to move fast, as they didn't have to chase enemy ships, so you get these absolutely ridiculous torpedo bulges.

I'm curious whether it was ever studied to have an outer plate that actually folds away from the ship while underway, leaving a gap filled with seawater between the plate and the actual hull of the ship. This would certainly create some extra drag, but my intuition (without actually crunching any numbers) is that it wouldn't be that bad. Perhaps that intuition is incorrect, though. Having a folding plate could allow it to be folded up against the hull when in dry dock, navigating a canal, etc., then folded back out away from the hull when back in open water. (Of course, this wouldn't help against modern torpedoes.)

👍👍

Well you have the steel crushing tubes that Royal Navy ships of WW1 used, the water as armour that the Nelrods had There is the terrible purgalese system that i believe if the Royal Navy had taken Vittorio Veneto on would have ripped out so the weight saved to improve her deck armour

Interesting, I would have thought spaced armor would fair much better than one single thick place, which is the case in tank amor, but that's mostly against armor piercing shells, so maybe protection against high explosive is different.

The whole "entering tanks" thing made me wonder; are there ever any hazardous atmospheres on the ship? Do you have to do any sort of air sampling before entering confined spaces?

Even as a diehard USN fanboy I have to say the Yamatos TDS pretty much proved itself the most effective given how many each ship absorbed and continued to function. Their shear size allowed tremendous depth of protection and that is the best defense protection. That said, I believe the system used by HMS Repulse was even more effective, avoid being hit altogether as long as possible!