Modern warships and armor

[jlb]

That's a pet peeve of mine: I can't see why modern warships don't carry any meaningful armor.

It's true it does eat up a lot of displacement, but steel and displacement aren't what make ships so expensive, and given the price of warships, it would appear that some armor would be very cost-effective.

Before you shout "shaped charge", let me point out a few things:

1) I'm not aware that anybody has shaped charge warheads ready for their anti-ship missiles today.

2) a shaped charge requires a specific impact angle for reasonnable efficiency, so a shaped charge carrying missile is much more limited in its attack profile options, which helps terminal defense.

3) a penetrating shaped charge inflicts much less damage to its target than a similar size straight HE warhead (except of course if you happen to hit something prone to brewing up).

4) spaced armor is very efficient at defeating shaped charges, and you have a lot more space on a ship than on a tank to fit it.

The shaped charge argument is the one I've always got, including from a naval engineer. As I said, I'm not convinced.

Steel isn't that expensive and you don't need battleship armor to significantly increase protection against regular antiship missiles (I'm putting the really heavy stuff like the SS-N-19 apart, but there aren't that many afloat).

Let's put it this way:

You want to protect a cruiser with 10cm high-grade steel, say a belt 100m long and 5m high. That makes it 100x5x2x.1=100m3 of steel, say it's really high density and it adds up to 800t of armor.

With 10cm you should be proof against a regular SSM like Harpoon or Tomahawk. So now your prospective ennemy has to switch to either shaped charge warheads or hypervelocity missiles if he wants to damage your ship.

Hypervelocity (even if only during the last few seconds before impact) means a bigger engine and more fuel, as well as a stronger structure and an AP cap, so you lose range and/or warhead size. Maybe the close AA defenses won't have as much time to engage this missile, but since it will have to fly in a straight line as it closes, it will be less able to evade them, so on balance the end result is maybe you still get hurt, but by smaller or fewer missiles or the other side has to come closer to shoot. In any case you have an advantage over an unarmored ship.

If the reaction is a switch to shaped charges it's even better. A large part of the damage caused by SSM's is due to leftover fuel in the missile igniting. With a shaped charge hit, resulting in a rather small hole, the missile's body, and thus its fuel, stays outside the hull.

Experience with HEAT hits on tanks also shows that if the warhead doesn't hit a fuel tank or ammo storage, the tank can usually be repaired, which is much less often the case with kinetic hits. Furthermore, again, spaced armor has proved quite effective against shaped charges, and there's a lot more room on ships for spaced armor than on AFVs.

So on a warship with extensive damage control facilities, HEAT hits should on average prove much less damaging than straight HE+fuel spill.

Again, I am not a naval engineer, and the only time I've had the opportunity to broach the subject with a professional - that was the engineer in charge of the CDG project at DCN back in 1991 - I was given the curt "shaped charges" and a dismissive hand wave and I was much younger than today and couldn't find a reply.

I'd very much like to hear the opinion of the professionals here. What did I miss?

 

[Wooki]

That's a pet peeve of mine: I can't see why modern warships don't carry any meaningful armor.

Again, I am not a naval engineer, and the only time I've had the opportunity to broach the subject with a professional - that was the engineer in charge of the CDG project at DCN back in 1991 - I was given the curt "shaped charges" and a dismissive hand wave and I was much younger than today and couldn't find a reply.

I'd very much like to hear the opinion of the professionals here. What did I miss?

What was the question? If you were just wondering what the most effective warhead for an antiship missile was, then the answer is --- it depends.

Shaped charges don't need any particular angle of attack to work. They work just the same regardless of the angle of the armor strike face, but it depends on your armor's thickness and other factors as to how well they work. This is true because the velocity of a shaped charge "jet" is so high as to make the angle of the armor strike face irrelevant.

A shaped charge also feathers out when it hits a strike face and then penetrates a large space, as you would find, say in a torsion box on a ship. So they are very good for igniting things if you make your shaped charge out of something that likes to burn.

The question of what warhead to use comes back to what are you trying to achieve?.... Do you want to sink the vessel (by primarily burning it) or do you want to neutralize it?

For example: It is easier to disable a ships sensors then to sink a ship, so having said that it might be better to use a fragmentation type warhead and knock the vessel out of the conflict that way (instead of using a shaped charge or other warhead type).

If it is easier to damage your sensors than how are you going to armor that? A belt of armor as you described would be useless in protecting a sensor array.

As you can see, it is a complicated question you asked (Or I think you asked) and I hope this helped a little.

 

[LancerMc]

Another reason why many modern warships do hot have armor is because many militaries believe in their protection suites for their ships. During WW2 there was no CIWS systems aboard ship. These system are designed to destroy a large number of targets missiles quickly. There are also much more advance SAM system on ships specifically designed to intercept incoming missiles before they reach any ship. Also do not forget fleet figthers and attack aircraft whose specific duty is to take out enemy aircraft and ships that launch attacks.

These systems must be pretty effective or you would still see ships having armour belts on modern warships.

 

[kotay]

So you put a belt of armour on the side.

And then your enemies use top attack munitions, a pop-up manoeuver in the terminal phase. So you put a layer of armour on your decks.

Then those skanky turds hit you below the belt with a torpedo. So you extend the side armour to below the waterline.

Then they make the torps explode under your keel, breaking your back. So you pour in loads of stiffening.

Then you find your ship doesn't move faster than 5 knots ...

Then you decide to invent defensive suites that prevent you from getting hit in the first place. Wahey! Freedom! Throw off the deadweight.

Sometime down the road, you again wonder ... what if I puit some, just some, not too much, armour on the side ... just for , you know ....

 

[KGB]

The ARA General Belgrano was a light armored cruiser that was dispatched by by HMS Conqueror using 2 ww2 era torpedoes during the Falklands war. A single hit on the rudder doomed the Bismark. The Hood was hit by a lucky shot .

I guess its much easier nowadays to deliver explosives than to protect against them.

 

[zoolander]

a missile weighing a couple tons containing a couple hundred pounds of military grade explosive, traveling mach .8 to 3 will puncture any type of armour period. Of course a couple of meters will stop that missile from going through but thats too impractical. Anyways certain missile like the Russian nuclear tipped missiles cannot be stopped.

Armour is just useless.

EW suites and SAMs are the modern equivalent

 

[KAPITAIN]

SS-N-19 and 22 are heavy anti ship missiles they have warheads 4 times the size of harpoon and exocet and go faster and further.

These missiles can be fitted with nuclear war head's but they are confined to conventional for now.

The reason that ships have little armour nowdays is because ships have become more expencive to build and fill with electronic equipment, gone are the days of 8 inch thick steel to stop 14 inch shell's, today we fire a volly of missiles so in comparison firing a 14 inch shell would be like taking a pea shooter to a cannon.

Kirov class even though designated battle cruiser does not have the same armour you would expect on a WW2 era battle cruiser, today its more about the complexity of weapons how many you can fit into one hull and how quick you can fire, the day of seeing you enamy before you fire is gone.

Also during the falklands war a heavily armed cruiser General Belgrano was sunk, a WW2 era cruiser but had heavy armour around it, the royal navy said it could have stood there and sunk our ships one by one without having any difficaulty.

So they fired on it first HMS Conquorer fired three MK8 torpedos (WW2 left overs) two hit and sank belgrano, so armour in that situation well is a waste of money destroyers and frigates and other small ships are designed to be expendable.

 

[Gaenth]

I think advanced armor composites will be used in the future for coastal patrol vessels, landing craft and the like which are exposed to small-arms fire or artillery, that's where armor is useful not on capital ships that are better disabled with Missiles or Torpedoes that are only going to get more effective.

On the AGA Belgrano issue, I think it's fitting that a WWII era ship was sunk with WWII era weapons, it only demonstrates that having armor was of little use back then and that a new approach was needed to catch up with explosives and weapon-delivery technologies. For the same reason I think it was a terrible mistake to deploy the AGA Belgrano, a waste of lives of brave sailors and a perfectly good ship, the chances of her getting close enough to damage any British Ship were minimal because it really was no match for modern naval weaponry, if HMS Conqueror wouldn't have sunk it, something else would, it was only a matter of time.

 

[zoolander]

During the cold war most if not all Moskit missile were nuclear tiped.(due to their first strike doctrine) Its a better idea to block rather than withstand attacks. and a heavy armed cruiser can easily be sunk or disabled by a a modern missile.
composits and light armour might work for a small boat but not a full size cruiser. Imagine the costs and effectiveness will be a problem.

Face it no existing armour can withstand a volley of super large super fast missile.

the warhead can easily hear the ship in half. The volosity and the kinetic enegy alone without the warhead can destroy a ship or badly damage a ship.

 

[gf0012-aust]

Face it no existing armour can withstand a volley of super large super fast missile.

there are a number of armour composites under development which do hold promise.

I'd argue that armour nowadays is not just about physical obstruction against an incoming weapon, but is a combination of physical and active processes.

as an aside, zoolander, you're flagged as being in america, but from my analysis, obviously are not - do you mind if I ask what nationality you are?

 

[KAPITAIN]

An exocet missile took out something the size of a type 42 DDG put it this way it wasnt a hard job these DDG's are small infact our type 22 FFG's are bigger!

As for a kirov, ive noted at least 3 types of SAM missiles each capible of engauging multiple targets simaltaniously, an exocet or harpoon would do little damage to a kirov (if it ever got threw) because of there small war heads.

Exocet and harpoon war heads are mesured in LBS unlike the russian ones Tonnes!