Zumwalt: Stealth and Armor in Modern Naval Combat

[GeoModder]

geo: This London Naval Treaty effectively ended on 1 September 1939 and the first Iowa class was ordered on 1 July 1939, it was a bloody treaty ship, so says those that know. there was some small change to underwater armoring which gained it some weight before the keel was laid, but it was designed as a treaty ship.
EOC? End of Conversation? never seen that meaning before.

On paper, you're right. In practice, I'm right.
I live in the real world.

[Nemo]

fifteen times greater... assuming the higher 30Gy value, always count pessimistically, 15 times higher gets us approx. 7 Gy inside a montana turret

And times 5 for the Shipwreck's low end estimated yield for 45 Gy. So well take the Montana turret armor of 22.5 inches and add 3 more inches, but I don't like halves so I'll round it down to 25 inches. The Zumwalt is 600 feet in length and has a beam of 81 feet. Well visualize a cylinder 520 feet long 80 feet in diameter, and a sphere 80 feet in diameter, then another cylinder and sphere that are that big minus 25 inches. Take the volume of the difference and work out that cubic mass. Lets see, just 36,076 long tons of steel to add to the Zumwalt's 14,564 long tons. 50,640 Long tons of ship.

A bit sloppy on the math I know,and check it as always. The cylinder ends are duplicating mass with the spheroid caps, but I figure it would take mass to adapt the armor shell to the ship so I figure that little bit can wash. You could make the shell out of lead instead, should come out to around 21,000 long tons. Lets just say 20,000 long tons on top of the Zumwalts 14,564 and call it 35,000 long tons.

[discord]

nemo: in other words possible, and there are other composites that does that perticular job better at lower thickness and weight.
the question as i pointed out is, is it in any way better than stealth and if so, is it practically applicable?

geo: a treaty is a piece of paper that the parties have agreed to follow, the design of the iowa followed the restrictions of the treaty in question, true both the gun size and BB tonnage had been increased within the treaty before it effectively expired due to war, but that still makes it a treaty ship.

[Nemo]

No not feasible. I'm just showing the math, its been thought through. Decrease the detonation range from 500 feet to 50 for 100 times the power and increase the yield on the weapon to 500 kilotons for the SS N 19's upper range estimate for a total of 500 times more power. That requires nine more halvings to reduce back to the same power. Up armor it again and I'll throw bigger and bigger weapons at it which also have already existed for decades.

All of which continues to assume air burst, even a fraction of that power under the ship would shred the hull. You can't have the nuclear impervious setup you want, the math doesn't support it.

[pinheadh78]

Just a thought; but if I can successfully hit you're nuclear-proof ship with one nuke (even a smaller one) then I can probably hit it with a second and third.

Given that I expect that you to have strong anti-air-war systems I'll be firing those nukes in salvos of probably 20 or more which can be delivered from a multiple attack vectors by submarine, surface, combatant, aircraft, and space transiting systems.

Point is, if the situation has escalated to the point of nuclear weapons, and your opponent really really wants your ship sunk. They will use as many nukes as it takes.

In a non-nuclear environment, yes you could probably build a super ship with crazy thick armor that is impervious to multiple anti-ship missiles. To that I would direct you to the battle of the German Battleship Bismark and Tirpitz for how the ship would hold up and eventually be sunk.

Bismark remained afloat after being hit hit several times by the WWII equivalent of an anti-ship missile; however it was mission killed (couldn't maneuver) after the torpedo hit its rudder then again after its primary guns were knocked out; even though most of the crew was still alive and the ship was floating. Tirpitz career was less remarkable having spent most of its time in port; however it showed that smaller anti-ship bombs and torpedoes couldn't sink it; what eventually sank it was gigantic custom-built bombs call tall-boys.

The best way to avoid those fates is to make it really hard for your enemy to see you (so they can't shoot their weapons in the first place) and then having very strong anti-air-war suite so you can shoot down the inbound conventional/nuclear missiles when they do find you. Eventually you would be mission-killed by either running out of missiles (hope you have guns as backup) or sustaining a direct or near-miss that shreds your own sensors.

[Nemo]

Just a thought; but if I can successfully hit you're nuclear-proof ship with one nuke (even a smaller one) then I can probably hit it with a second and third.

On that thought, don't think I mentioned it yet but the Shipwrecks were fired in salvos. They networked together and autonomously coordinated their attack on a target too. Not bad for 70s tech, assuming it actually worked. It was Russian after all.

[pinheadh78]

Yes exactly; anti-ship missiles are usually fired in salvos and from multiple vectors. No one shoots them in just one or two as they expect that a percentage will be shot down.

Read the chapter "Dance of the Vampires" in the novel Red-Storm Rising by the late Tom Clancy for an idea of how a modern soviet-style anti-ship missile mission would probably play-out.

[discord]

pin: the question as you so nicely danced around it is between armor and stealth.

#1 stealth on ships do NOT work, they are not invisible, there was a phase in tank development the leopard 1 is a prime example with the same school of thought, we can see them first and shoot'em first, they came up with 'nah, this shit do not work, lets put some armor back on.' there have however been no naval engagements to prove either way, but my gut feeling is some armor is better than no armor, and it will be a bloody massacre.

#2 lowered RCS or other signatures is all good and well...but not if it breaks EVERYTHING else(zumwalt), and my argument is that it is of questionable advantage compared to armor, the one does not exactly exclude the other though.

nemo: and at what standoff range would a zumwalt be wrecked? that armor at least gives the ship some distance to shoot the missile down, now, we do not know the exact numbers on the effects of nukes, but crossroads gives us a ballpark, given that piggie outside the turret died 2 days later the initial thermal/kinetic waves did not kill it...

found a little program that might be reasonably accurate.
http://nuclearsecrecy.com/nukemap/
500 REM range is about 5 Gy, so for a shipwreck(upper estimate, 500kt) against a unarmored ship, about 2.2km, that gives us a number to work with to figure out initial radiation burst.
so assuming these numbers, a shipwreck at 150m would dish out 1075.5Gy, so about eleven inch of steel(or less of more advanced stuffs, lets say 12 for good measure) would do the trick, problem is it would have to be omni directional, thereby heavy as bloody hell, but doable.
and on the under ship explosion, assuming it explodes UNDER the ship, and throws it up, given enough depth and tough enough sealed vessel, it should just bob back up a bit worse for wear, not exactly under? push it to the side, most of the ships in Baker shot survived just fine....the question is crew survivability, difficult to be sure here, but probably tricky.

so a 12 inch armor(as long as it is from the side, Iowa would qualify with 12.1 inch belt armor) could survive a shipwreck at 150m, a zumwalt would suffer crew death at 2km.
no armor is effing stupid.

[Zakharra]

Since the conversation has nukes, assuming some armor is added (I agree, some of is better than none, otherwise the ships aren't much better than armed merchant vessels) what would it take to put reasonable radiation shielding in areas of the ships? Is it feasible?

[pinheadh78]

Stealth tank you say? The Polish army is working on one
http://foxtrotalpha.jalopnik.com/is-pol ... 1554395391

Personally I don't like the idea ;tanks are very dirty and abused in cross country and small-arms/heavy-weapons hits. I dont think that Polish stealth tank would stay stealthy for long.

Ships on the other hand operate in relatively clean environments on the ocean where you need to worry about salt, corrosion, water, and whatever stuff is floating on the water.

Also; I didn't dance around the argument, just pointed out that if your enemy can see you they can also hit you. And even if you can shrug off the first or second hit and keep fighting eventually a mission-kill will be achieved. The way to avoid that fate is to have low observable ship with enough armor to shrug off small arms and either evade or shoot-down inbound threats; and of course work as a team with the other ships and assets around you. As noted earlier that once the conflict goes nuclear then don't expect armor to save the ship as repeated nuclear near-misses would achieve mission-kill.

Its also telling that almost universally modern surface combatants are being built with stealth features as standard; and those are actual Navy's that have to face the real-world threat.

[discord]

pinhead: but it does not work, not against a first rate navy....ffs all you need is satellites, ships are big objects, and that is if you could achieve invisibility to radar and other sensors(which they do not by any stretch), good passive thermal sensors can spot a squirrel at a few kilometers, radar can pick out mach speed baseballs in thousands at rather long range....IT DOES NOT WORK.

and the 'clean' environment is a reason why it does not work, easier to spot things....but it's not clean, lots of 'ground clutter' which shows where you are, sensors are insanely good today.

[pinheadh78]

I think I see where the disconnect is; the purpose of stealth on warships is not to make them 100% invisible; its to make them look like something else on radar and thermal vision.

Radar alone can't tell you what your looking at; it can only tell you speed, direction, and rough size of the object your looking at. On a radar screen a big pre-stealth warship moving at 15 knots looks like a very large blob amongst allot of smaller blobs (fishing boats, small trawlers, small cargo, etc). For a hostile warship or inbound anti-ship missile seeking a target its easy to pick out the warship as its the really big blog. This is how the Russian P-700 and similar missiles work to find the ships they are supposed to prioritize; go for the one with the big return as that's the carrier.

But if you add stealth to the warship and cut its radar-return by even 60 percent; now that blob on the radar starts to look like all the other blobs on the radar. Now the hostile warship or inbound missile has to figure out which of those blobs is the real warship. Make the radar return small enough and it becomes harder to select which blob is the background clutter and which is the ship.

An enemy could still detect you if your the blob that's going 30+ knots as most small-craft and ships can only do 20 knots; but if your radar-return is as small as a fast speed-boat then that's what radar thinks you are and an un-aware radar operator (human) might mistake you as. Same goes for stealth-aircraft in that they would look like rain-clouds or large bird flocks (or ground-clutter if viewed from above) to hide. The Serbs got wise to this and re-calibrated their radars to specifically target flocks of birds (the F-117); especially ones going 500+ mph (the other factor was the idiot in charge of mission-planning kept flying the stealth aircraft down the same valley and same height every night so the missile-crew knew when and were to aim in advance).

So to recap, the point is not to be 100% absolutely invisible to everything (as yes a satellite can still see the ship or its wake); the point is to make it harder to figure out which is the warship and which is an innocent merchant ship or even a small frigate instead of a gigantic cruiser turning the targeting phase of an attack or to confuse an inbound cruise missile.

[discord]

pinhead: civilian ships? again, peace time military, or one for use against third rates who do not have satellite surveillance, nor high altitude optical capacity.
and what does a oil tanker look like? a big fat blob moving around?
and on nukes? see a group of ships, it ain't friendlies, toss a few nukes in for proximity detonation, problem solved....or a spotter plane of some kind, because if the other side has air superiority the kiddie gloves come ALL the way off.

what i have been trying to say, modern warships are not designed for war....

another thing, just thinking about the bismarck, it was stopped by a torpedo from a old airplane that happened to hit the exact could of square meters(rudder) where it could do any damage whatsoever, and stuck the ship into a turn, a vector jet configuration does not need a rudder....and that weakness gets much smaller.

[GeoModder]

geo: a treaty is a piece of paper that the parties have agreed to follow, the design of the iowa followed the restrictions of the treaty in question, true both the gun size and BB tonnage had been increased within the treaty before it effectively expired due to war, but that still makes it a treaty ship.

Guess we can only agree to disagree.

[Nemo]

Guess we can only agree to disagree.

For what its worth, you're both right. The Iowa was designed as a Panamax fast battleship. Its beam was constrained by the size of the locks. Since it was intended as a fast battleship its length was constrained by the hydrodynamic equations derived from David Taylor Basin ship model studies governing waterline beam:length ratios. Given the max width of the canal as a constant, a ratio of 1:7.96 is derived.

The treaty was designed to limit construction in peacetime to save money, but not all politicians were Chamberlains. Escape clauses were included within the treaty that allowed signatories to build up their ships. The tonnage limit in the escape clause was lifted from 35,000 long tons to 45,000. This is not an accident. This was the expected tonnage of a Panamax capable warship. Both the United States and Britain wanted to constrain spending and limit potential foes as they both required access to the Atlantic and Pacific and designed the treaty around a hypothetical Iowa. Of course, this was not lost on potential foes Germany and Japan who only needed one ocean fleets.

The Iowa was not constrained by the treaty, the treaty was constrained by the Panamax Iowa. Even then the Iowa exceeded the escape clause tonnage limit of 45,000 tons to, among other things, increase her secondary battery because yes they were ignoring that limitation at the design phase.

[JQBogus]

1) The 155mm AGS on Zumwalt has a far higher rate of fire, each gun being considered about the equivalent of an entire battery (6) of M109s in delivered fire.

2) While both guns have a projectile diameter of 155mm, and carry a roughly equivalent bursting charge, the AGS round is more than twice as heavy. More propellant, a longer barrel, and a stronger/longer burning rocket motor means a lot more range. Nothing fishy there, really.

3) A Burke class destroyer costs $1.8b dollars. I very much doubt that one could build an Iowa equivalent today for $1.6b, no matter what a simple inflation calculation from its 1940s cost says. Even without its armor, an Iowa weighs ~2.5x as much as a Burke. That much more structure, piping, wiring, etc. And since it is a ship designed to carry on with its mission despite maybe being hit, that many more radars, fire controls, and so on, as redundancies. Oh, and while steel may cost only $1000/ton, most of the cost of armoring a ship wouldn't be in the materials, but in the labor. 2.5 Burkes = $4.5b, plus the cost of the armor and armor installation. A modern BB would cost more like $5b or $6b, probably.

4) And that's only the Unit Cost. Zumwalt has 140 crew. Iowa (80s refit version) had ~1800. Figure a 50 year expected lifespan on the ship, and each crew member costs $30k/year per average, with benefits. Crew cost for Zumwalt is $210m over it's lifespan, while crew cost for Iowa would be $2.7B. Add in the unit costs, and Zumwalt = $3.7b, while Iowa would be $7.7-8.7b. So you get 2 to 2.33 Zumwalts per Iowa.

Anyway tired of writing, thats all for now.

[discord]

JQ: on a modern remake of a iowa(or similar) i agree that 1.6 is more than a little optimistic, but simpler construction methods(no fancy pants radar absorbent materials or such) but yes, doubtful the unit cost would be under 3b.
a 'new' BB would undoubtedly be larger, nuke powered, and larger again....and with R&D probably at a few billion to boot, would be at a guess 5-6b/unit assuming at least two ships....yup, in agreement there.

crew...could probably be a hell of a lot lower compared to iowa, under 500 should be possible, less redundancy in crew admittedly, but should not be a major issue.

and on construction, it would be relatively simple, a nice uniform 2-3 inches ballistic steel used EVERYWHERE, do note, just plain steel is about half the cost of ballistic steel, 700USD/ton whereas armor steel is 1000+.
this uniform armoring makes repairs simpler, same plate thickness can be used on multiple ship types, and should keep both material and construction costs down, steel is simpler to work with compared to fancy pants stuff.

but seriously though, a simpler and smaller design might be in order....designed as a long ranged independent light cruiser, at about 10-15k ton range, armored patrol ship(would need defense against .50 and RPG's approx.), primary use in peace time? piracy patrol and flag waving, war time? Aegis(and decoy, due to zero stealth) for caps, useful for up and coming naval officers as learning ships.
weapons? i would design it with a couple of bofors 40mm twin barrel turrets(multi purpose+CIWS), Maybe a 5 inch gun, some VLS cells, ASW, and a helo pad.

http://en.wikipedia.org/wiki/DARDO <---- pretty much that, updated for bofors 3p rounds, those are nasty.

[Senanthes]

JQ: on a modern remake of a iowa(or similar) i agree that 1.6 is more than a little optimistic, but simpler construction methods(no fancy pants radar absorbent materials or such) but yes, doubtful the unit cost would be under 3b.
a 'new' BB would undoubtedly be larger, nuke powered, and larger again....and with R&D probably at a few billion to boot, would be at a guess 5-6b/unit assuming at least two ships....yup, in agreement there.

crew...could probably be a hell of a lot lower compared to iowa, under 500 should be possible, less redundancy in crew admittedly, but should not be a major issue.

and on construction, it would be relatively simple, a nice uniform 2-3 inches ballistic steel used EVERYWHERE, do note, just plain steel is about half the cost of ballistic steel, 700USD/ton whereas armor steel is 1000+.
this uniform armoring makes repairs simpler, same plate thickness can be used on multiple ship types, and should keep both material and construction costs down, steel is simpler to work with compared to fancy pants stuff.

but seriously though, a simpler and smaller design might be in order....designed as a long ranged independent light cruiser, at about 10-15k ton range, armored patrol ship(would need defense against .50 and RPG's approx.), primary use in peace time? piracy patrol and flag waving, war time? Aegis(and decoy, due to zero stealth) for caps, useful for up and coming naval officers as learning ships.
weapons? i would design it with a couple of bofors 40mm twin barrel turrets(multi purpose+CIWS), Maybe a 5 inch gun, some VLS cells, ASW, and a helo pad.

http://en.wikipedia.org/wiki/DARDO <---- pretty much that, updated for bofors 3p rounds, those are nasty.

I've got a couple questions...

One is on the use of 2-3 inch ballistic plate. What are you armoring it against? I mean, it will stop small arms, but an RPG-7's PG-7V warhead (the original, if memory serves), will ideally penetrate 10.24 inches of RHA (lets halve that for a REALLY terrible hit, so 5.12 inches), so I'm not too sure if it would even be worth the effort as opposed to, say, a layer within the hull to contain the blast... And it certainly won't stop anything fired from another ship, CIWS, ships gun, or missile. How is it not just dead weight and extra cost?

Secondly, from the description in the latter part of your suggestion, isn't that pretty much an (possibly upsized) Arleigh Burke with steel plates and a couple of 40mm twin turrets? Why bother with the plating when it wont stop the threats envisioned? Just use the Burke.

Don't get me wrong, I can see a use for gun platforms beyond 155mm or 5 inch, but armoring up every ship in the fleet with thin steel plating really doesn't seem like it would be much more than an expenditure of resources for little to no performance increase. If we're going to increase protection, why not go with Kevlar liners within the hull in addition to those they already have around critical areas? Or ERA mounts on the outside? Or just mount a few active defense modules (ala Trophy, ARENA, ad nauseum) below the CIWS systems to protect against smaller munitions?

[discord]

senanthes: the points are as following.
#1 the current generation ASM are not designed to penetrate armor at all, so pretty much ANY armor will make them explode on the outside, making them pretty much ineffectual, this is the primary reason for a thicker external armor.
#2 arbitrary number, mostly for it being the amount of steel you need to halve primary radiation(Gamma), ease of math.
#3 seems like a reasonably easy thickness to work with, economics and ease of repairs and maintenance, keeping costs down.
#4 the primary current and future threat would be HEAT based weapons, steel plating is notoriously bad at stopping those, and the use of spaced armor is well known to be effective against HEAT(with liquid filled spacing for external and 'vitals' for extra defense).

think of it like this, first layer will trigger the HEAT, and might wreck the room behind it, but will not go further, damage contained, layers upon layers....this armoring scheme is of course most effective with really large ships, liquid spacing breaks up the explosive jet, since it has to move the water while there is no place for it to move, pretty much the same for kinetic...forces the penetration to basically have a much larger penetration cross section, improving effectiveness of armor.

the optimal thickness and ratios is to me unknown, i am not a materials engineer with a specialization in armor, but it seems to me that ANY armor is better than no armor, and spaced liquid filled(exactly what you fill it with....dunno, but non-newtonian fluid pops to mind.) armor should work pretty well.

#5 such a armored extra anti-stealthy cruiser would also be a gloriously good escort and decoy for stealthy capitals...

#6 in the role of pirate hunter, it would need protection against .50 and RPG-7 and that is about it, 2inch+liquid+2inch external armor should stop most of that.

[Nemo]

And once more, the next generation missile capable of destroying this thinly armored ship could be designed tested and fielded in large quantities before this ship is complete.