No an anti-ship missile modern day can beat Iowa Battleship-class ?

[blackadam]

Iowa Class: Armor Protection

One of the main characteristics of a battleship is its ability to withstand an attack. Few ships from the past and no modern ships can equal the survivability of the Iowa Class Battleships. The decision of where to armor and how much armor to use is a very complicated and sometimes frustrating process. Simply adding armor can not be done since this greatly increases weight and reduces the top speed of the ship. The process of protecting a battleship is an art that has been perfected over decades of battleship design. Iowa Class Battleships are an excellent example of superior armor protection and high top speed.
The armor systems of the Iowa Class ships can be divided into two basic sections. First is the above water armor, which is designed to protect the ship against gun fire and aerial bombing. The second is the below water armor (side protective and triple bottom armor), which is designed to protect the vessel from mines, near miss bombs and of course, torpedoes.

All the systems needed to keep these ship's combat effective such as magazines, engineering spaces, steering, plotting rooms, command & control, weapons, etc. are protected by heavy armor. The armor box, referred to as the citadel, extends from just forward of Turret 1 to just aft of Turret III. The top, sides and ends of the citadel are heavily armored, however the bottom is not ballistically protected. Critical systems located outside the citadel such as the turrets, conning tower, fire control, directors, etc. are armored extensions of the citadel...
Iowa Class: Armor Protection - Naval History Forums

The Armor:

Armor
The second basic factor, after firepower, to be considered was Iowa class armor. The armor scheme was a copy of the armor used on North Carolina and South Dakota, only thicker. This armor could, in theory, stop a 16-inch shell coming in at a 45-degree angle. There was some idle talk about making the Iowa class armor tough enough to stop an 18-inch shell, but BDAB dropped the idea when it realized how much more weight and redesign work it would take.

Nickel-steel was used to manufacture the armor. This type of steel is a kind of stainless steel which has the added benefits that it does not corrode quickly, but bends easily. Nickel-steel was not a new material. From the start, armored warships like USS Indiana (BB-1) used this type of steel. One 17 1/2 inch belt of the nickel-steel ran from the deck to the below water line on both sides of the ship and covered the middle 2/3 of the ship. Eighteen inch plates were used in the turrets and 11 1/2 inch plates were placed on the decks.

It is interesting to note that much of the Iowa class's armor is just as thick as battleships built 50 years earlier. Wisconsin and her sisters, however, benefitted from advances in steel technology that allowed mills to forge the steel at higher temperatures and heat treatment, which in turn produced a much higher quality steel that was stronger and more elastic. Two plants, Bethehelm Steel's main mill in Bethehelm, PA and Luken Steel's Coatsville mill just ouside Phildadelphia, manufactured most of the armor plating. For the turret plate, however, a special forge was constructed just for the Iowa-class at the Charleston Ordnance Works in Charleston, WV...
http://www.globalsecurity.org/military/systems/ship/bb-61-design.htm

Thus, all of today's anti-ship missiles (example: Kh-35/31, RGM-84, Exocet, C-803, YJ-18, LRASM, P-270/700/800/1000, NSM, TLAM Block IV, Brahmos.....) can not do anything with the armor of Iowa, unless they attack in large numbers (100 or more)

 

[blackadam]

I'll calculate basic

The Japanese Yamato was struck by some ten torpedoes, mainly on the port side, and several bombs before she sank. Musashi and her consorts were attacked by hundreds of U.S. Navy carrier aircraft. This battlewagon was hit by some nineteen torpedoes and seventeen bombs. Though her heavy protection withstood this massive damage to a degree probably unsurpassed by any other contemporary warship, Musashi capsized and sank about four hours after she received her last hit.

Just to give an idea of how much punishment BBs can take.

Standard USN air droppable torpedos weighed 1005kg/2216 lbs and had warheads with 262kg Torpex. Typical aircraft armaments in these cases consisted of 454kg/1000lbs and 227kg/500lbs. Respectively, these contained about 241kg and 119kg of HE explosive.

Name Type Bomb-Weight HE-Weight
AN-M30 GP 100 lb 54 lb
AN-M57 GP 250 lb 123 lb
AN-M64 GP 500 lb 262 lb
AN-M65 GP 1,000 lb 530 lb
AN-M66 GP 2,000 lb 1,051 lb
AN-M56 Light Case 4,000 lb 3,245 lb
AN-Mk1 Armor-Piercing 1,600 lb 215 lb

By comparison

P-800 Oniks
Warhead 250 kg (551 lb)
P-700 Granit
Warhead weight 750 kg (1,653 lb) HE (unknown composition, probably RDX or similar) or 500 kt fission-fusion thermonuclear weapon


Assuming Mk13 torpedos and 500lb bombs were used, it took at least some 3 tons of explosive to sink Yamato (and 7 tons to sink Musashi). That's the same weight of explosive as in 4 (9) SS-N-19 or in 12 (28) SS-N-26. Between 11 to 15 torpedo's and at least 7 direct AP bomb hits to sink the Yamato. Let's Remember ! The anti-ship missile operates mainly sea-skimming

And armor of Iowa better than Yamato/Musashi, it plated by nickel-steel

Unlike modern warships, which operate on the concept of eliminating an incoming threat (anti-ship missiles or enemy aircraft) before the given threat strikes a ship and thus carry lighter armor, the Iowa-class was designed and built in an age when ships were expected to withstand an onslaught of naval shells from enemy ships, emplaced coastal defenses from fortified enemy positions near the coast, and the increasing threat of gunfire and armour piercing/ incendiary bombs dropped by enemy fighter and bomber aircraft. Like most World War II era battleships, the Iowa-class was equipped with class B armor plate designed to a post Jutland design (the "all or nothing" armor scheme), but unlike earlier WWII-era battleship, the Iowas benefitted from advances in steel technology that allowed mills to forge the steel at higher temperatures and heat treatment, which produced a much higher-quality, stronger and more elastic armor. The metal was a nickel-steel compound, classified as a stainless steel, that can bend easily and resists corrosion. Most of the armor was manufactured at Bethlehem Steel’s main mill in Bethlehem, Pennsylvania, and Luken Steel’s Coatsville mill just outside Philadelphia, Pennsylvania. The exception was the turret plating, which was forged at a plant built especially for the Iowas: the Charleston Ordnance Works in Charleston, West Virginia.

Subsonic missiles would be less devastating degree, due to the speed and low weight of their warheads, so they need more than 100 missiles to destroy targets such as Iowa

I think Iowa is still a threat if it still works and upgrades

 

[Carl Schwamberger]

Well, they dont work (operate) any more and its become horrendusly expensive to upgrade anything of significance on them. The cost of keeping just one combat worthy, let alone four of them, was cutting into construction of new & badly needed classes of ships. Might be cheaper to refloat the Olympia

 

[alspug]

What you are missing is that although the Citadel itself is fairly strong it is armoured on an all or nothing Scheme . In other words the remainder of the ship is going to be full of holes and completely wreathed in fire . Fire will kill any Ship with ease and fire fuelled by exotic jet and or rocket fuels will be hard to extinguish . The smaller Exocet and Harpoon style missiles would do little , however once you get to the KH-22 style missiles their is a large Hollow Charge warhead that will penetrate and armour on any battleship ever built .

 

[pdf27]

Where to start...

1. Anti-ship missiles are far from the only or even biggest threat to a ship like the Iowa. Indeed, what is IIRC the biggest ship to be sunk after WW2 (the Belgrano) was lost to submarine torpedoes. Designing to meet a one-dimensional threat is a good way to lose a war.
2. One of the reasons that navies have moved from "survive being hit" to "don't be hit" is that an awful lot of critical equipment simply can't be put behind armour. Radar waveguides for instance cannot be placed behind armour, so would be shredded in any anti-ship missile attack: you may not have the ship sinking, but if it's mission-killed and needs 2 years in a dockyard before it can fight again what's the difference?
3. At the time the Iowa class were retired, the threat was that incoming cruise missiles would have nuclear rather than conventional warheads. No armour on earth is going to do you any good against a direct hit by a 20kT nuclear warhead.
4. What are they supposed to do? Laser-guided 16" shells don't exist, so what you have is a very expensive (as many crew as a supercarrier) grid square removal system which can only work at very short range in waters which are secured against enemy submarines and cleared of mines. Since the actual targets you have to deal with are very small, a whole Iowa class battleship is about as effective as a single F-35 armed with precision bombs.
5. Quite apart from the all-or-nothing armour scheme mentioned, you're also assuming that anti-ship missiles will hit the belt armour. This is not really true any more - the Standard missile for instance has a highly effective anti-surface mode (so good in fact that they deleted Harpoon from ships that carry it), which is effectively plunging fire with the missiles screaming down from an apogee of ~100,000 ft to hit the deck armour. The deck is harder to armour than the belt, and so is vulnerable to hypersonic missiles coming in almost normal to it.

 

[ObssesedNuker]

The conventional warhead casing on the SS-N-19 is built like a bunker buster bomb, it is quite capable of punching through the Iowa's armor. Only the internal damage controls is why it would require more then one. Plus, mission kills are a thing.

 

[Lost Freeway]

I'll calculate basic

One of these things is not like the others.

 

[King Augeas]

All the vulnerabilities proven in WW2 remain. You cannot armour the communications and radar gear. Flooding of the unarmoured bow and stern will greatly reduce speed and range. Damage to the boiler uptakes and exhausts will also reduce speed. Plus it's relatively easy to redesign a missile to have sufficient armour-penetration capability - or, presumably, to aim just short of the waterline, dive under the belt and explode inside the citadel.

But all of this misses the point really. Battleships became obsolete because of their lack of offensive potential.

 

[steamboy]

And you're also ignoring things like the sheer kinetic impact of missiles. The ones used against the RN in the Falklands half the time didn't explode, the Sheffields didn't, it ripped a hole in her side and spread jet fuel everywhere. A big Soviet SSM like an SS-N-19 or an AS-6 is not going to slam into the ships side, its screaming down from very high altitude at very high Mach 2+ speed. It weighs over a ton and has an armour peircing nosecone. If that hits the superstructure then its going to be carnage. Same with it slamming in around the DP 5-inch mounts, they could not take a hit like that and they tend to be full of shells and propellant.

I also recall reading about the Soviets developing a HEAT warhead for some of their big SSM's. A HEAT warhead would LOVE all that armour, it just makes the cutting jet bigger.

 

[HMS Warspite]

Battleships are capital ships to start with and cost a lot of resources to build, maintain and crew. Even the strongest build battleship is vulnerable to damage and can be destroyed easily with one good hit of whatever weapon intended as a anti shipping device, whether it be large calliber shell, bomb, missile, or torpedo. With a battleship either damaged, or lost, the cost of this loss will certainly affect its owner and replacing it by another big expensive monster is not logical then, as much cheaper more efficient alternatives exist, both in the past and in the present.

More important: the battleship has no defenses against underwater attack, either mine, or torpedo, as a single torpedo can kill it completely with one good hit, just as HMS Prince of Wales was lost already by the first torpedohit, which caused her own propellorshafts to tear her hull open to the ocean, damaging her fatally. Any such hit and resulting damage to any ship is fatal. Iowa is designed with a relatively below average underwaterdefensesystem, not to be repaeted in the proposed successor.

 

[Tyr Anazasi]

The invulnerability of BBs against modern SSM and ASM is limited to smaller ones like Exocet and Harpoon. Bigger ones or older ones like the SS-N-2 Styx missiles remain a threat. Or cruise missiles. So for example, if an RBS 15 missile can't sink the ship, a (or two or three) Taurus cruise missiles can. And for such big ships some missiles would be spared.

 

[Tyr Anazasi]

Battleships are capital ships to start with and cost a lot of resources to build, maintain and crew. Even the strongest build battleship is vulnerable to damage and can be destroyed easily with one good hit of whatever weapon intended as a anti shipping device, whether it be large calliber shell, bomb, missile, or torpedo. With a battleship either damaged, or lost, the cost of this loss will certainly affect its owner and replacing it by another big expensive monster is not logical then, as much cheaper more efficient alternatives exist, both in the past and in the present.

More important: the battleship has no defenses against underwater attack, either mine, or torpedo, as a single torpedo can kill it completely with one good hit, just as HMS Prince of Wales was lost already by the first torpedohit, which caused her own propellorshafts to tear her hull open to the ocean, damaging her fatally. Any such hit and resulting damage to any ship is fatal. Iowa is designed with a relatively below average underwaterdefensesystem, not to be repaeted in the proposed successor.

I am just writing a TL, in which the Iowa class will have a part. Could you please explain the underwater defense systems and armour protection?

 

[Hammerbolt]

Torpedoes. One or 2 and the BB will risk, at the very least, having to go home at a slow speed. Or, if it has a Bismarck-dose of bad luck, it looses it's steering gear.

Or the enemy starts firing nuclear-tipped missiles...

 

[Summoner]

From my discussions with some dudes in the army, armor/tank guys specifically, It seems that HEAT rounds, while devastating to tanks might not have the same effect on battleship armor. A heat round makes a tiny hole in the armor and "injects" a jet of molten metal. Lethal to a tank since crew, ammo, vitals are all within a few sq ft of one another. The molten metal jet kills the crew, ignites flammable/explosive materials and either directly destroys or mission kills the tank.

My assumption is that a heat based warhead would most likely cause localized damage but perhaps not like the sort of destruction a tank would suffer. The battleship is massively larger. With hundreds of compartments, dispersed layout and systems redundancy, they can mitigate the damages of heat. One reason why the older style AP shells that were designed to actually punch through the armor plate, detonate internally and hope for a critical hit.

 

[Redbeard]

In a night action in 1942 a modern US battleship the USS South Dakota for some time effectively was incapacitated by relatively light Japanese gunfire. The heaviest shells hitting were a few 14” but most 8” and smaller. None were even close to penetrating the armour into vitals, but so much cabling etc. in the superstructure was cut that the ship was blind (it was a night action) and couldn’t fight back effectively. Had it not been for the USS Washington arriving in the right moment and time the USS South Dakota most likely would have been sunk by IJN destroyers or cruisers closing and torpedoing her.


I do not here talk about the event in the same battle where an engineering officer took all electrical power from the ship by an unintentional short circuit of the entire electrical system, but about the damage done to the ship outside the main armour. But of course this event didn’t help much and anyway point to the vulnerability of complicated machines.


This was not because the South Dakota was a lousy ship, probably her design belonged to the finest ever, but already by 1942 warships were far too complicated to keep efficient when hit.


Keeping a hull afloat after substantial damage is not the most difficult part, they had become quite efficient at that by WWII. Another example would be Bismarck’s final battle. She was hit by hundreds of shells from two battleships but stayed afloat for hours and had to be sunk by torpedoes (and perhaps scuttling). But long before that she had stopped to be a fighting unit as her main armament was overwhelmed inside the first 20 minutes of the battle.


I would love to see a battleship on the seas again, but it would be a very expensive way to provide floating targets for the enemy and anyway wouldn’t stand a small nuke.

 

[BlueTrousers]

If the answer to your question is battleships, and the year is later than about 1955, then you asked the wrong question. The effect of an anti-ship missile on a battleship is roughly equivalent to a 9.2-inch shell that doesn't miss. It may not penetrate the citadel, but it will trash everything outside the citadel. It will start extensive fires. The ship probably won't be sunk, but it won't be fighting.

And if you get serious about battleships, it won't take long for someone to build an anti-ship missile designed to kill them. Put an armour-piercing warhead on a P-700, and you've got a 15-inch shell that doesn't miss, and has the armour penetration at 600 miles that a gun has at the muzzle.

My assumption is that a heat based warhead would most likely cause localized damage but perhaps not like the sort of destruction a tank would suffer. The battleship is massively larger. With hundreds of compartments, dispersed layout and systems redundancy, they can mitigate the damages of heat. One reason why the older style AP shells that were designed to actually punch through the armor plate, detonate internally and hope for a critical hit.

HESH might actually work better against armoured ships than HEAT. The behind-armour effects would be quite impressive, and they'd completely ruin the upperworks as well.

 

[HMS Warspite]

I am just writing a TL, in which the Iowa class will have a part. Could you please explain the underwater defense systems and armour protection?

Nor is propellant containment the only weak point in the Iowa Class battleship’s design. Their underwater protection system is known to be defective by many naval architects. But very little was said about this important area of concern before, or since, the Iowa Class were reactivated. The US Navy is aware of the scope of these defects, but has done nothing to rectify a situation that could be calamitous should these ships suffer damage from modern torpedoes of mines.

In the Iowa and South Dakota designs both weight and the advent of Japanese shells with underwater trajectories had to be considered. The designers felt they did not have sufficient weight margins available to employ a heavy multi-layered system against underwater attacks and thick side armor as well. In lieu of making the design changes necessary to employ separate underwater and shell protection system, American naval designers opted to use a common system for both purposes. As Oliver North would say, “It was a neat idea.”

The side armor of the Iowa class was set several feet inboard, and inclined internally at 19 degrees to the vertical until it reached the top of the ships’ triple bottoms. It was reasoned the side armor would thus form a formidable torpedo protection bulkhead (6.4″ to 1.62″) as well as keep shells with underwater trajectories out. Despite the lack of full scale tests, the system was immediately incorporated in both the South Dakota and Iowa Class. That’s good old Navy foresight for you, although in all fairness to the designers they were pressed for time due to the looming war.

In 1939 the Iowa’s under-water protection scheme was finally tested on full scale models in the Philadelphia Navy Yard. The results of the trials were very disappointing. It was discovered that the heavy Class B armor used in the torpedo bulkhead could not bend enough to accept the gas pressures generated by large underwater contact explosions. The system failed due to armor plate cracks and structural failures where the bulkheads joined into the ship’s triple bottom. These defects allowed flooding to take place behind the main torpedo bulkhead, and the system had to modified.

The modified torpedo protection system was tested in 1943 at the Philadelphia Naval Yard. The results were less than satisfactory and again showed structural defects, but these faults were deemed acceptable. Corrective plans were finally drawn up, but they were too late for the Iowa and her three sisters. Had the Illinois and Kentucky (Iowa Class near sisters) been completed, they would have incorporated the improved torpedo protection scheme. However, their construction was halted and both ships were ultimately scraped.

Some Navy officials were displeased with the Iowa Class’s underwater protection scheme very early on. In 1944 P. W. Snyder, a Commander in the Bureau of Ships, filed a scathing report on the battleships’ design. He felt the Iowa Class needed six feet more beam and better sub-division to have adequate torpedo protection. But Snyder’s recommendations were rejected by his superiors. It was felt a wider hull would make the ships slightly slower and unable to go through the Panama Canal. Improving the ship’s internal sub-division was too expensive and time-consuming to even consider. So in the end nothing was done.

Richard Debobes, a staffer for the Senate Armed Services Committee, was unaware of the 1939 and 1943 trials on the Iowa Class’s torpedo protection system. “I can’t comment,” he said. “You must understand that there is an investigation of the turret explosion. These other concerns you have brought up have not even been discussed.” It would appear that the Committee’s staffers are so intent on studying one tree that they are failing to take into account how the forest is faring.

But Debobes is not alone in his unfamiliarity with the trials on the Iowa Class’s torpedo defense system. No staffer from either the House or Senate Armed Services Committee was aware of these tests. Considering the greatly improved performance of the latest torpedoes, one would hope someone notices there’s a problem here. The underwater pressure forces created by modern torpedos and mines are far greater than those that were used in the Philadelphia tests. Two or three hits by modern underwater explosive devices might be more than sufficient to disable or capsize one of these glass-skirted leviathans.

What is of more concern is the possible use of underwater weapons with large shaped-charge warheads. If one of these was to hit an Iowa Class battleship there is the distinct possibility hot gases and debris could penetrate one of their magazines–especially the magazine that supplies Turret I (the turret closest to the ship’s bow). The magazine of Turret I is closer to the sides of the ship than the magazines used to supply turrets II and III. The vulnerability of Turret I’s magazine has been a source of concern since these battleships were designed but the Navy accepted the risk given the fine forward hull form needed to achieve the Iowa Class’ high speed.

Admiral Kinnear admitted that the Iowa Class’s underwater protection was suspect before the ships were reactivated. He said, “We knew that the ships’ underwater protection was a potential weak point, but I don’t recall being briefed on the tests that took place in Philadelphia.” Kinnear went on to say that survivability and armor distribution talks took place in Navy Secretary Lehman’s office, but the precise details of these talks can’t be released for security reasons.

Navy spokesperson Walker didn’t know about the Philadelphia tests on the Iowa Class’s underwater protection scheme. “I’m not aware of those tests,” he said. “Nothing is in the works to improve the ships’ underwater protection that I’m aware of. I don’t think it’s an area of concern.” After being told about the Philadelphia test results Walker continued to insist the reactivated battleships “can take more torpedo hits than most ships” in the modern Navy. Walker’s view certainly doesn’t say much for the underwater protection of our modern warships.

Ship Record’s John Reilly also didn’t recall any details about the Philadelphia tests, but said rectifying any shortcomings in the Iowa Class would be difficult. “You’re talking about a total underwater rebuild, and it’s not necessarily worth it,” he said. “The ships are protected by escorts that will keep submarines away.” Reilly explained the Iowa Class has a number of redundant systems that should limit damage from torpedoes. However, he refused to speculate on the effect a shaped-charge torpedo warhead would have on an Iowa Class’s magazines.

But there are other areas of concern regarding the reactivated battleships besides their dubious underwater protection scheme. Navy spokesperson Walker said the Iowa Class has the thickest armor of any warship afloat. But enormous areas of these battleships are completely unarmored. Of course, these unarmored areas just happen to be where many Navy crewmen serve during battle-stations–another “neat idea.”

 

[Summoner]

HESH might actually work better against armoured ships than HEAT. The behind-armour effects would be quite impressive, and they'd completely ruin the upperworks as well.

HESH I believe would also suffer from the same effects as HEAT on a battleships. Again, the extensive compartmentalization would save the battleship. HESH is not really designed to penetrate armor but rather transmit a shock wave through the solid metal. Where it reaches the "end" of the armor on the interior of the ship, it projects pieces of armor at high speed throughout the interior, starting fires, killing crew. I cant help but think it would just cause localized damage and nothing else. Also, HESH can be mitigated by spall liners on the interior.

Furthermore, the faster the missile goes, the more HESH performance suffers. HESH anti-tank rounds are low velocity. As excess speeds serve to disperse the pat of plastic explosive when striking the exterior armor. The trend with anti ship missiles is come in as fast as possible and this is counterproductive to HESH.

Upon further though, the one area on a battleship highly vulnerable to HESH would be the battleship turrets themselves. Large amounts of crew, propellant, delicate machinery in a tight cramped space with large amounts of armor to transmit the shock wave; much like a tank. Perhaps the armored crew citadel as well.

 

[Hammerbolt]

Btw, we do have severall relevant historical examples: the efects of Fritz-X on WWII ships.

The BB Roma sunk with 2 hits, the BB Warspite was penetrated top-to-bottom by a single missile... I'll grant the Iowa's armour was better (?) than theirs, but, then again, this was a WWII weapon. While modern ASM missiles aren't specifically built to penetrate armour, most travel faster, adding a lot of kinetic energy to the impact. The Brahmos, for example, weighs over twice the Fritz-X and travels at close to Mach 3. The P-270 is even heavier. That's a lot of kinetic energy...

 

[King Augeas]

I would think that the metal jet produced by several hundred kg of explosive in a HEAT antiship missile would be rather larger, and hence reach a lot further into a ship, than that from a tank shell. But I also suspect that it's better to just put an armour-piercing head on it and just punch through the armour, like the Fritz-X.

HESH velocity shouldn't be a problem for subsonic cruise missiles, relative to tank shells. There may be a good chance of the blast entering the turrets via the gun embrasures too?