Missile Pod Concept

[Egil Skallagrimsson]

The thing about warhead size and the supposed ability of armour to defeat is that during WWII capital ships, heavily armoured BBs amongst them, were shown to very vulnerable to successive hits from bombs,

Correct. And todays missiles are designed to hit straight forward. Not to come in from high altitude and hit as a bomb would.

Oh, I accept that there is an element of rock/paper/scissors about this, but I don't see anybody rushing to build a new generation of Dreadnoughts. Different decades, different threats. If you needed to sink a Iowa, in 1945 or 2011, you would go about it the same way as sinking the Yamato or the Musashi, repeated air attacks (bombs or missiles), I suspect the Iowas would have been very vulnerable to the plunging ASMs the USSR had in service by the 1980s.

(ok, if you had a good SSN you might try that instead).

Egil

 

[Mongoose Pete]

Correct. And todays missiles are designed to hit straight forward. Not to come in from high altitude and hit as a bomb would.

I think you've forgotten the DF-21D ASBM...

In addition most modern ASM are designed with optional "pop up" attack vectors to dive vertically into a target ships deck; such as AGM-84A, Konsberg NSM, Noor 2, Raad and Yingji-82.

 

[phavoc]

Large capital ships came about because they needed to be big to a) do their intended job and mount big guns / big flight decks, and b) once you invested all that money in a big ship, you needed to protect it in some way.

Used to be armor was the way to protect yourself against the big guns from the other ships. And you had screening elements to protect you against other weapon systems and the other guys screening elements.

Today we don't armor ships as well, but their active defenses more than make up for that difference. Missiles have gotten smaller AND bigger, faster and smarter to penetrate better defenses. It's a constant game of cat-and-mouse, and it always has been. The HMS Dreadnought made all previous ships obsolete the day it launched, thus ushering in a new arms race. A Nimitz class carrier and its battlegroup can defeat virtually every other naval power in the world, and even if nukes are being tossed around, they are still a very hard thing to kill.

It will be interesting to see where the next major arms race takes us. Gunwise it looks like railguns are going to bring back the "big" guns, though if the Navy ever builds anything beyond a cruiser to mount them is, as far as I know, unlikely. Unless someone else has seen/heard something on the drawing boards.

Maybe the Navy needs to let DARPA design its next major weapons systems?

 

[DFW]

I think you've forgotten the DF-21D ASBM...

In addition most modern ASM are designed with optional "pop up" attack vectors to dive vertically into a target ships deck; such as AGM-84A, Konsberg NSM, Noor 2, Raad and Yingji-82.

Hardly. The D model is NOT designed to carry enough HE to go after heavily armoured targets. It's designed to go after unarmored aircraft carriers. Pop-up doesn't give speed to emulate a large bomb dropped from altitude.

Physics is your friend here.

Egil, I never commented on the worth of a BB as an offensive weapon but simply its armour vs. current anti-ship weapons so, your question as to why no one is building them is irrelevant to what I was talking about.

 

[Egil Skallagrimsson]

Egil, I never commented on the worth of a BB as an offensive weapon but simply its armour vs. current anti-ship weapons so, your question as to why no one is building them is irrelevant to what I was talking about.

Sorry, my question was rhetorical. It was obvious by 1941 that the battleship was becoming a white elephant. Of course many modern anti-ship weapons are not designed to deal with a heavily armoured BB. Should anyone start to build one I am sure that new ASMs will quickly appear in western counties, and the Russians would dust off some of their Cold War carrier killers. In the interim, back to bombs (probably laser guided this time) and torpedos. Agreed, the relatively limited offensive power of a BB compared to a CV was also a reason to stop building them, but defensively they were a broken reed by WWII anyway.

Egil

 

[Mongoose Pete]

Sorry, I was refuting your comment that modern missiles are designed to hit straight forwards. This is patently false.

Hardly. The D model is NOT designed to carry enough HE to go after heavily armoured targets. It's designed to go after unarmored aircraft carriers. Pop-up doesn't give speed to emulate a large bomb dropped from altitude.

Physics is your friend here.

!?! What planet are you on?

Forgive me, but unless I'm dreadfully wrong, a vertically striking near 1 ton warhead travelling at mach 10 is going to really spoil your day, even in a BB. Physics is indeed your friend in this situation. And that doesn't even count the 600kg of high explosive.

If you still don't believe the D model is enough to cripple a BB, then try comparing it to the shells fired by a 16" gun. A WWII era 16" shell weighs near the same mass (1,225kg), has only 18.5kg of HE and travels at mach 2.25 at barrel exit. That was enough to penetrate the armour of a BB. Since the DF-21D ASBM is travelling at a very minimum of five times faster at impact (probably much more) and carries thirty times the explosive (with better designed penetrative qualities), what makes you believe it would be unable to harm a heavily armoured target?

 

[DFW]

!?! What planet are you on?

Forgive me, but unless I'm dreadfully wrong, a vertically striking near 1 ton warhead travelling at mach 10

I'm on Earth; apparently a different planet than yourself. The missile quoted doesn't hit a ship at Mach 10 (7,600 mph) otherwise, it would be designed as a penetrator without a HE warhead.

When you arrive on Earth (and finish needed college courses), look me up.

 

[phavoc]

A reference page for the 16" guns of the Iowa class battleship - http://www.navweaps.com/Weapons/WNUS_16-50_mk7.htm

There are/were two types of shells - HE and AP. Each had a different muzzle velocity. I've yet to find anything that lists the velocity of the shell at impact. However, for any math whizzes out there, here's what is listed:

Avg muzzle velocity leaving the barrel - 2,424 FPS
Mass of shell - 2700lbs (1,225 kg)

Assume range of 34,000m
I do not know the required angle of the gun to reach the target, and therefore I don't know the maximum apogee height of the arc.

 

[Mongoose Pete]

I'm on Earth; apparently a different planet than yourself. The missile quoted doesn't hit a ship at Mach 10 (7,600 mph) otherwise, it would be designed as a penetrator without a HE warhead.

According to the Chinese before they cancelled their development of another ASBM the DF-25, they say that it was designed to carry a propellant reserve to accelerate it to mach 10 prior to impact. Assuming they carried over the concept to the DF-21 it could be capable of mach 10(*). Even without the reserve acceleration system, the projectile would still inherently retain a ballistic impact velocity of mach 6-8.

Comparing the KE alone, between a 16" AP shell travelling at an average velocity of mach 1.34 and the DF-21D travelling at a potential mach 10, the ASBM has 45 times the kinetic energy. If we say the Chinese were spouting hyperbole and the warhead merely strikes at an average of mach 7, then its still 22 times the KE.

So whatever your opinion you're obviously on a different planet to the Chinese, since they are making ASBMs which carry 400-600kg HE warheads (among other types including nukes) that strike at mach 7+. Its a capital ship killer which could easily sink any BB.

(*)Most modern ICBM warheads have an impact velocity of around mach 10 after deceleration through the atmosphere.

 

[locarno24]

Actually, we haven't a clue what velocity the DF-21 hits at. Whilst it's been declared to be at 'operational capability', at no point yet has there been any announced or observed tests - the hopes of watching a test fire was why there was quite a significant interest in the recent(ish) fleet exercises.

I haven't actually seen a definitive statement as to the warhead, either.

That said, comparing to other MRBMs is a good rule of thumb. It is following a ballistic missile flight profile, so it's going to be falling pretty close to vertical during it's terminal attack. I'd say a free-fall penetrator is a pretty good damage model. The key is actually hitting with the thing - with a flight time somewhere the wrong side of a quarter of an hour, against an evading target capable of making significant speed (supposedly 30+kts flank speed for a US supercarrier)*.



Regardless, as noted, it's not really bombs or shells that are the biggest threat (until you get up to really big bombs, anyway) - the real giant-slayer of proper capital ships, from the Bismark to the Belgrano, has always been torpedos. Which, since they are usually delivered by either aircraft or submarines, both of which are opponents a battleship struggles to fight effectively, makes them doubly scary.

Underwater explosions are nasty - water's largely incompressible nature makes for some seriously unpleasant effects, and means that even a lateral, non-contact detonation can cause serious damage to a ship's innards, whilst the ideal hit - a heavyweight** torpedo, detonating a few metres under the keel amidships - is quite literally back-breaking.



* Of course, if the carrier is making flank speed and zig-zagging, it's going to be maintaining limited air operations at best. Which is, I guess, sort of the point.

** 650 lbs for a Mk 48, so big but not that big compared to some bombs that have been used for attacking warships.