Torpedoes vs. big ships

[Joku]

So, essentially, what kind of damage a single modern torpedo would cause to a large ship such as an supercarrier or a Iowa class battleship?

[Kodiak1]

The Iowa was about as heavily reinforced against underhull torpedo detonations as possible on its frame. That said, the mentioned sweeping frame has some inherent weak spots and the rating is only up to ~ 700 lb TNT warheads. The Mk. 48 has a 650lb modern HE warhead, so probably well north of 1000lbs TNT.

It certainly won't be fun for the Iowa. I don't think you'd sink it, but you probably knocked it out.

I'd be surprised if anything definitive on the Nimitz's ability to absorb under keel torpedo hits is publically available. I'd also be surprised if the number was greater than "2."

Either is in a really bad way if you steer the torp around and hit their screws, just like any other ship.

[MarekGutkowski]

Originally Posted by Kodiak1

Either is in a really bad way if you steer the torp around and hit their screws, just like any other ship.

It was my understanding that soviet 650mm wake homing torpedo was design to do just that.
Russian believed that it required 4 direct hits with a conventional warhead to put a Super carrier out of commission. Don't know how much russia knew about them and there ability to absorb damage but that figure seams plausible. I guess that Iowa may survive 4 hits with a 650mm but that may get her scuffled if the treat is still out there.

The number of treats for a CV in modern warfare its so large it isn't funny.
I read that life expectancy of a CVN in a total war with the soviet circa 1970's was 24hours. Then again "Mysl Wojskowa" magazine has about as much credibility as a James Bond novel.

[Richardson]

That might be due to the fact of how long it would take for the nuclear armed bombers to find it and fight through it's CAP.

[Apocal]

If nukes are flying, nothing is going to last long.

[ObssesedNuker]

It is dependent upon the torepedo. Is it a keel-snapper*? Is it a super-cavitating one? How big is its warhead?

*Is that the nickname for torepedo's that detonate just under the ship?

[Entropy]

Honestly the Iowas had a pretty mediocre torpedo protection scheme even for it's time, just like the earlier SoDaks they were partially derived from, which were using the same scheme. There's a reason why the Montanas were set to revert to the Norcar scheme, IIRC it worked better.

Either way, it's not going to be a fun time for an Iowa. A supercarrier is probably built to much better withstand a torpedo hit, since the design is going to just be that much more modern and better subdivided.

[Apocal]

Originally Posted by ObssesedNuker

*Is that the nickname for torepedo's that detonate just under the ship?

Not that I've ever heard. But I'm a carrierman not a submariner.

Originally Posted by Entropy

Either way, it's not going to be a fun time for an Iowa. A supercarrier is probably built to much better withstand a torpedo hit, since the design is going to just be that much more modern and better subdivided.

In some ways yes, in others no. Obviously under the keel detonations are going to fuck shit up and carriers don't have comparable armor to a battleship in any regard. Although on a similar note, the USS Enterprise is the last ship in the US Navy with a torpedo belt.

[MarekGutkowski]

Originally Posted by Apocal

In some ways yes, in others no. Obviously under the keel detonations are going to fuck shit up and carriers don't have comparable armor to a battleship in any regard. Although on a similar note, the USS Enterprise is the last ship in the US Navy with a torpedo belt.

To my knowledge no ship in history had armor to with stand a 406mm (16'') torp detonating under the keel.

Keel is the underbelly of any ship. The nature of underwater explosions, can be compeered to a shape charge, with the energy moving upwards.

For serious stuff I direct all that are interested too.
http://www.navweaps.com/index_tech/tech-047.htm
Probably the best online source on naval war ever.

[Apocal]

Originally Posted by MarekGutkowski

To my knowledge no ship in history had armor to with stand a 406mm (16'') torp detonating under the keel.

Keel is the underbelly of any ship. The nature of underwater explosions, can be compeered to a shape charge, with the energy moving upwards.

Uh... it's nothing at all like a shaped charge. It's because water is incompressible, so almost all of an explosion is directed upwards; lifting a dozen tons of water is much easier than compressing it. Path of least resistance, remember?

The actual blast from an under the keel shot doesn't even need to touch the ship, the expanding bubble of steam produced by the explosion does all the heavy lifting. Literally. It physically lifts the keel, weakening it slightly, then the bubble collapses and the ship, quite literally, falls into a hole in the water. And ships weren't built to be picked up and dropped down into holes, so the keel, suddenly weakening from the lifting of the bubble, suddenly finds itself under some serious stress, the absolute most likely outcome being it breaks in half, sometimes along with the whole ship.

Physical size is some defense, but there are some monster torpedoes out there with equally monsterous warheads designed to take on larger ships.

[MarekGutkowski]

Originally Posted by Apocal

Uh... it's nothing at all like a shaped charge. It's because water is incompressible, so almost all of an explosion is directed upwards; lifting a dozen tons of water is much easier than compressing it. Path of least resistance, remember?

The actual blast from an under the keel shot doesn't even need to touch the ship, the expanding bubble of steam produced by the explosion does all the heavy lifting. Literally. It physically lifts the keel, weakening it slightly, then the bubble collapses and the ship, quite literally, falls into a hole in the water. And ships weren't built to be picked up and dropped down into holes, so the keel, suddenly weakening from the lifting of the bubble, suddenly finds itself under some serious stress, the absolute most likely outcome being it breaks in half, sometimes along with the whole ship.

Physical size is some defense, but there are some monster torpedoes out there with equally monsterous warheads designed to take on larger ships.

Yes that is what I was thinking. Shaped charge analogy was that energy is directed up, not that it compressed the water, the gases do most of the work. If the explosion actually makes a hole in the keel, it presses the watter inside the ship. A hole made in the side will push watter in with the force of gravity, explosion under the keel will have effect like a pressure cocker steam.

Under keel explosion is something there is no real counter for it. Armoring the bottom is not possible in any functional and worthwhile degree.

We are getting of topic, not all torpedo his are under the keel anyway but they are the most dangerous ones.

[Joku]

Originally Posted by Apocal

Uh... it's nothing at all like a shaped charge. It's because water is incompressible, so almost all of an explosion is directed upwards; lifting a dozen tons of water is much easier than compressing it. Path of least resistance, remember?

The actual blast from an under the keel shot doesn't even need to touch the ship, the expanding bubble of steam produced by the explosion does all the heavy lifting. Literally. It physically lifts the keel, weakening it slightly, then the bubble collapses and the ship, quite literally, falls into a hole in the water. And ships weren't built to be picked up and dropped down into holes, so the keel, suddenly weakening from the lifting of the bubble, suddenly finds itself under some serious stress, the absolute most likely outcome being it breaks in half, sometimes along with the whole ship.

Physical size is some defense, but there are some monster torpedoes out there with equally monsterous warheads designed to take on larger ships.

So, it is not practical or possible to strengthen the hull to better withstand underwater explosions to any reasonable degree?

[Roi Danton]

Originally Posted by Joku

So, it is not practical or possible to strengthen the hull to better withstand underwater explosions to any reasonable degree?

Possible maybe, but just how much would you be prepared to sacrifice to achieve that?

[archon476]

How do catamaran or Trimaran ships do against torpedoes?

[Apocal]

Originally Posted by Joku

So, it is not practical or possible to strengthen the hull to better withstand underwater explosions to any reasonable degree?

Against an ideal shot, no, it's the actual weight of the ship, not it's displacement, bearing down on the keel that snaps it. Normally, the incompressibility of water is helping out tremendously in that regard as it can carry much more than the keel could ever hope to. But the bubble takes that away briefly and the ship breaking in two is the normal outcome.

Sheer physical size helps somewhat, but the effect doesn't scale correspondingly to the threat; you make your destroyers the size of carriers with keels three times as tough and it's still a trivial exercise for any potential opponent to upgrade the size of their torpedo warheads to still get the same effect.

Originally Posted by archon476

How do catamaran or Trimaran ships do against torpedoes?

Far worse than monohull designs because that gap or gaps represent a further structural weakness.

[Somebody]

But that only applies if the torpedo detonates under the hull. Detonating underneath that huge space in split hulls would do nothing, wouldn't it?

[PhantomVX2000]

Originally Posted by Somebody

But that only applies if the torpedo detonates under the hull. Detonating underneath that huge space in split hulls would do nothing, wouldn't it?

No, the water splash would surge up from an underwater detonation and slam against the connection. It wouldn't be very pretty for the ship regardless of the designs.

[DonBosco]

Originally Posted by Somebody

But that only applies if the torpedo detonates under the hull. Detonating underneath that huge space in split hulls would do nothing, wouldn't it?

I don't think the gap is going to be large enough to matter. Looking at this video, it looks like it's wide enough to go completely across the beam of the vessel.

[Apocal]

Originally Posted by Somebody

But that only applies if the torpedo detonates under the hull. Detonating underneath that huge space in split hulls would do nothing, wouldn't it?

Actually, I honestly don't know. What I do know is that the detonator wouldn't trigger on the empty spot, it'd trigger on one hull or the other. I don't think it's ever been properly tested however.

Originally Posted by DonBosco

I don't think the gap is going to be large enough to matter. Looking at this video, it looks like it's wide enough to go completely across the beam of the vessel.

Not to steal your thunder, but here's a slightly longer vid that actually shows the initial upward lifting motion and then the fall into the hole in the water that breaks it's back. Aussie MK48 SINKEX

[The Wild Turkey]

Originally Posted by Apocal

Actually, I honestly don't know. What I do know is that the detonator wouldn't trigger on the empty spot, it'd trigger on one hull or the other. I don't think it's ever been properly tested however.



Not to steal your thunder, but here's a slightly longer vid that actually shows the initial upward lifting motion and then the fall into the hole in the water that breaks it's back. Aussie MK48 SINKEX

For those interested, that the Farncomb sinking the Torrens in 1999.

http://en.wikipedia.org/wiki/HMAS_Torrens_(DE_53)

[Skyllian Blitz]

Originally Posted by Apocal

Actually, I honestly don't know. What I do know is that the detonator wouldn't trigger on the empty spot, it'd trigger on one hull or the other. I don't think it's ever been properly tested however.

Possibly what could happen is that the explosion tries to force both hulls apart which could lead to the hulls shearing off due to the stresses. Either way, it will still lift the ship then drop it since the force still remains the same, just that pressure may be lower.

[An Ancient]

Exactly where it hits can make all the difference, as Prince of Wales found out in WW2, a single hit near the stern can kill your ship if it bends a propellor shaft, which will then do the work of wrecking the hull up for you.