USS Iowa vs. her weight in 1790s British frigates

[Iceberg]

Well, if I've learned anything from this thread, it's that the majority of SDnetters believe that I am, in fact, insane.

[phongn]

Well, if I've learned anything from this thread, it's that the majority of SDnetters believe that I am, in fact, insane.

You like mecha, duh </obligatory HAB comment>

Next up on SDN, Nazi Germany vs. the United States but with 2003 technology and historical OOBs.

[Zoink]

All the British ships fire, by some freak incident a canon ball lands in every Iowa gun barrel just as it’s firing. The resulting conflagration destroys Iowa’s turrets.

So, that makes there odds what? 1 in 10^100 ? Maybe 1 in 10^83 if they're saying "Arghh!" at the same time?

[Rogue 9]

Not Argh. Arrrrr. Argh is the sound of panic or frustration, which they would be experiencing.

[Perinquus]

To give you an idea of just how much ordnance is coming out of those barrels, it takes a modern supercarrier flying airstrikes 12 hours to put the same weight of ordnance ashore that an Iowa class battleship can put ashore in 18 minutes!.

Wait, are you sure about that? There's not actually that much explosive even on the HC 16" shells, despite their enormous weight.

I read it in a pretty reliable source. It was a well researched book on the history of U.S. Navy battelships. Unfortunately, it's no longer in my library. There's more explosive in a 1900 pound HC (high capacity) 16 inch shore bombardment shell than there is in a five hundred pound bomb. And a battleship gun can fire again in about thirty seconds, where a carrier plane has to return to the carrier, land on the deck, refuel, reload with bombs or missiles, hook up to the catapult, relaunch, fly back to the target area, etc. etc.

This is why the battleships served so long after they were obsolete for ship to ship combat. They were absolutely devastating for shore bombardment. And with modern electronics and cruise missile launching capabilities, they remained competitive warships - especially with all that armor, which would make them largely immune to missiles like the exocets that sank the H.M.S. Sheffield during the Falklands war.

IIRC, the USN estimated it'd only take six Exocets to take down a battleship. The armor is not particularly useful against modern ASMs.

Again, the source I read indicated otherwise. The exocet is designed to kill a modern warship, and for that it does not need all that powerful a warhead. Modern warships have largely dispensed with armor, and rely on being able to destroy inbound missiled before they hit. Most modern naval vessels carry no more than a few inches of armor plating at most, and in an effort to save weight, have even used aluminum in their superstructures. By contrast, the Iowas were all built in an era before missiles, and since you could not shoot down or destroy an incoming shell back then, the ships were built to withstand the tremendous destructive power of naval gunfire.

The underwater protection was sesigned to absorb the energy from an underwater explosion equivalent to a 700 pound charge of TNT. All the systems needed to keep the ships combat effective such as magazines, engineering spaces, steering, plotting rooms, command & control, weapons, etc. are protected by heavy armor. There is no modern warship with survivability comparable to that of the Iowa class battleships.

[Melkor]

Just out of curiousity, would a Phalanx CIWS be able to shoot down an incoming 16 inch shell. How does the speed of an incoming missle and shell compare?

[CmdrWilkens]

To give you an idea of just how much ordnance is coming out of those barrels, it takes a modern supercarrier flying airstrikes 12 hours to put the same weight of ordnance ashore that an Iowa class battleship can put ashore in 18 minutes!.

Wait, are you sure about that? There's not actually that much explosive even on the HC 16" shells, despite their enormous weight.

Part of that might be pointing out that despite the capacity of 100+ aircraft even the Nimitz-class usually doesn't have more than two or three dozen planes available for air to mud work. A lot of the problem would be due to the loss of the A-6 and its heavier capacity but nonetheless you can't expect an aircraft carrier to be rotating more than about 36 plaens through strike missions. Given that those planes will, today, mostly be F/A-18Es they have a rather limited conventional capacity wheras, as was poitned out, the Iowa can sustain a round down range every thirty seconds until her ammo supply is exhausted.

With relaod and refuel (plus refit) times on aircraft you aren't going to get more than 2-3 missions per day out of each and even if you could cram that all into 12 hours it gives you MAYBE 72 sorties, most likely yes. In 18 minutes the Iowa should crank out upwards of 36 rounds so if the capacity of a single 16" HC was twice what an -18E can carry he's definately right though if it were equal then either you would have to assume fewer sorties 9likely) or add some time for the Iowa (possible too).

[Sea Skimmer]

To give you an idea of just how much ordnance is coming out of those barrels, it takes a modern supercarrier flying airstrikes 12 hours to put the same weight of ordnance ashore that an Iowa class battleship can put ashore in 18 minutes!.

And the carrier's aircraft can do so over ranges of several hundred miles with higher accuracy, and while the munitions weight is the same aircraft bombs pound for pound pack far more explosive.

This is why the battleships served so long after they were obsolete for ship to ship combat. They were absolutely devastating for shore bombardment.

To a point, however far cheaper and 6 and 8 inch cruisers could destroy almost all targets a battleship could anyway. With heavy fortifications, well it was really just a matter of getting lucky and having a shell hit directly on an embrasure.

However battleships once obsolete rapidly left service, the Vietnam reactivation was greatly opposed by much of the Navy and came very close to being called off in favor of the alternative, which were two heavy cruisers. The 1980's reactivation was driven by the demand to get Tomahawks into the fleet quickly and cheaply.

And with modern electronics and cruise missile launching capabilities, they remained competitive warships

Once your done piling enough new equipment on they can be competitive, but there incredibly inefficient no matter what, a mere Perry can and sometimes does carry as many or even more Harpoons while cruisers and destroyer with a fifth the displacement carry twice the Tomahawks and with 350 rather then 1500 crew.

- especially with all that armor, which would make them largely immune to missiles like the exocets that sank the H.M.S. Sheffield during the Falklands war.

Quite completely wrong actually. The USN calculated that six Exocet missile hits would have a 40% chance of sinking an Iowa and would knock the ship out of action regardless. Exocet hits high in the hull, well above the armor, and then starts a massive fire. The armor can't protect against that. It also can't protect against the most common threat anti ship missile, the Styx/Silkworm. That missile hauls around a shaped charge weighing nearly a thousand pounds that will easily pierce any thickness of armor on any battleship, though its main intention was to blast open a long line of compartments, allowing the missiles large fuel load to spread throughout the ship. That will still be happening to the Iowa, the Russians tested the missile against one of their old battleships among other things, with the warhead jet reaching well into the engine room

The Iowa's also have massive radar signatures that chaff launchers would be hard pressed to mask. In any case, a modern warship no matter the armament is near worthless without an extensive electronics and communications fit, and there is no way to armor those systems.

[Perinquus]

Just out of curiousity, would a Phalanx CIWS be able to shoot down an incoming 16 inch shell. How does the speed of an incoming missle and shell compare?

Probably not. Even if the phalanx could hit it, it probably could not destroy the shell. Missiles can be destroyed inbound because they are actually quite light. Any extra weight degrades performance, so they are built as lightly as possible. A 16 inch shell, on the other hand, is almost solid metal carrying an explosive charge. It's quite heavy, as it needs to be to withstand the tremendous force of the powder explosion that sends it on its way. Any 7.62mm bullets that managed to hit one would probably bounce off with little to no effect, and not even significantly deflect it in its flight path, unless one managed to hit the fuze.

[PeZook]

<snip?

Any 7.62mm bullets that managed to hit one would probably bounce off with little to no effect, and not even significantly deflect it in its flight path, unless one managed to hit the fuze.

Phalanx CIWS is actually a 20mm gun.

EDIT: And the Silkworm, for example, weighs twice as much as a 16-inch shell (it's 2300 kg vs. 2100 pounds if i recall correctly) - this with relevance to the claim about how CIWS shoots missiles down in flight because they are light.

[Sea Skimmer]

With relaod and refuel (plus refit) times on aircraft you aren't going to get more than 2-3 missions per day out of each and even if you could cram that all into 12 hours it gives you MAYBE 72 sorties, most likely yes. In 18 minutes the Iowa should crank out upwards of 36 rounds

As many as 324 shells actually, though that is very unlikely since at longer ranges it would mean firing the next salvo before the first impacts.

so if the capacity of a single 16" HC was twice what an -18E can carry he's definately right though if it were equal then either you would have to assume fewer sorties 9likely) or add some time for the Iowa (possible too).

A 16 inch HC round has a 154 pound burster, a single Mk82 bomb has 275 pounds, Mk83 416 and a Mk84 945. The BLU-109 has around 315 as I recall, it might be a bit higher then that. This does mean the HC round is going to throw out alot more fragments, but the explosive power is much lower. Then theres cluster bombs, which are around 15 times more effective then the same weight of unitary shell or bomb, unless the target has significant overhead cover.

[Sea Skimmer]

Phalanx CIWS is actually a 20mm gun.

And its ammunition is actually an 11mm saboted penatraitor, made of either DU or Tungstun. Its can crack the sometimes armored shells of an anti ship missile warheads to explode them very well. But a 16-inch shell would almost certainly be too strong. However its highly unlikely the system could ever hit such a fast and small target.

[Perinquus]

<snip?

Any 7.62mm bullets that managed to hit one would probably bounce off with little to no effect, and not even significantly deflect it in its flight path, unless one managed to hit the fuze.

Phalanx CIWS is actually a 20mm gun.

Oops. My mistake. Hmmm... I'm not sure even a 20mm could do it, but it just might. I doubt it could hit one though. The shells travel at 2,690 feet per second. I haven't yet found any data on the speed of ASMs, but I don't think they're that fast.

[PeZook]

Phalanx CIWS is actually a 20mm gun.

And its ammunition is actually an 11mm saboted penatraitor, made of either DU or Tungstun. Its can crack the sometimes armored shells of an anti ship missile warheads to explode them very well. But a 16-inch shell would almost certainly be too strong. However its highly unlikely the system could ever hit such a fast and small target.

Well, it WAS just a minor nitpick

[Sea Skimmer]

Oops. My mistake. Hmmm... I'm not sure even a 20mm could do it, but it just might. I doubt it could hit one though. The shells travel at 2,690 feet per second. I haven't yet found any data on the speed of ASMs, but I don't think they're that fast.

One or two designs can get close to that, but most anti ship missiles are in the high subsonic range, though all recent designs are in the mach 1.4-2.5 range and they are rapidly growing in number. But for costal defence the current favorite is multiple rocket launchers. They won't sink ships, but there's no way a vessel can escape being hit dozens if not hundreds of times and the submunitions will tear up the substructure and electronics of anything. Though using them to drive an warship into a minefield can be a very nasty tactic.

[Zoltan]

I dont think it can be done. I think the Iowa would own them.