In a peer fight involving hypersonics where the potential defended footprints possible with weapons like PAC-3 or SM-6 are - due to the intercept geometry challenges - so small as to almost point-defense range, there is some logic to needing your missile-shooter having a good enough sensor suite to at least protect itself.
In any event, since LRHW range is currently bigger than unrefueled CVW strike fighter range for the foreseeable future, there's also an argument that the CVW will be the primary defensive shield of the fleet, with the LRHW or weapons like it being the primary alpha strike, at least in the opening phases against critical targets.
That's worth noting, I hadn't thought of that. I assume offboard targeting is viable? Couldn't you use an Aegis-equipped warship to guide in a missile from whatever platform is most advantageously positioned?
I feel like we have to find a solution that doesn't involve a billion-dollar radar on every single boat in the fleet.
capital ship guns force enough other constraints onto a ship that it's likely they're no longer viable as an offensive weapon, even if we're doing Gerald Bull things to them and launching say 8" extremely low drag shapes out of a 12-16" tube for ludicrous range. What did they call it, "Strategic Long Range Cannon"?
Thing is, once you get past about 25km range, you really do need a terminally-guided cannon projectile. Because a 1mps difference in muzzle velocity will put your point of impact off by over 250m. A 1-mil error in gun azimuth will put you off by (range in km).
Accuracy at long range is a good point, but there are gradations of costs here. A steerable fin and either GPS or a seeker head is one level of cost--the projectile you're proposing is going to need thrust vectoring and glide wings. For evidence, look at LRLAP and look at Excalibur. Both are guided 155mm rounds, but LRLAP cost $500,000 per round delivered and was expected to increase to $800,000-$1,000,000 each. They also never demonstrated the claimed range. Excalibur, on the other hand, reached a peak price of $250,000 each in the early days and is now around $70,000 each. So by increasing the capability of the round from "guided" to "guided and self propelled" we have caused a 2x to 14x price increase, depending on which numbers you take. For a VGAS system, you are talking even more complexity than LRLAP.
Because a ship with LRHW and the AAW flag is getting shot at by high end AShCM and AShBM strikes, plus whatever hypersonics the enemy chooses to throw your way.
Yes, so it will have BMD escorts. I'm in favor of defending warships that need defense, I'm not in favor of giving every warship every capability under the sun.
Ships spend a whole lot of time doing things other than shooting, and having a couple of helicopters is such an advantage for all the other jobs (plus ASW) that the Burke IIs added a 2-ship helo hangar instead of just the lily pad of the Burke Is. Nevermind those little British ASW frigates with hangar space for a pair of Sea Kings!
Yes, helicopters are an advantage for all these other jobs
that a missile boat shouldn't be doing! Why does a Burke need ASW helicopters? Design and build a dedicated ASW destroyer/frigate that isn't trying to pull double duty as AAW.
None of this is a satisfactory answer for "why should a dedicated ballistic missile warship waste space on irrelevant capabilities."
The point of naval gunfire support is that the ship is already at the firing position, in the hot zone. Because it takes way too long for a ship to get into position after a call for fire. 30 knots is 30 nautical miles per HOUR, you cannot hide 100nmi off the coast and respond to a call for fire in less than 3 hours.
You need to be waiting so close to the shore that you're scraping barnacles off the hull, and you're going to need to gangster lean the ship to gain a couple more degrees of gun elevation to shoot far enough inland.
What *is* the mission here?
To be honest, as much as I love big guns, I am having a hard time imagining any plausible target or mission set existing that would justify new construction super-large naval guns. The AGS CONOPS, even if it were valid today, does not need super-large guns, since no common land target (AFVs, foxholes, camouflaged berms and trenches for ATGMs/AT guns/howitzers) needs anything bigger than 8" (203mm) HE or cargo - and those are the only target sets that can let one argue the point that you'd rather use naval shells to blow them up rather than more expensive munitions.
Really the only target that might justify super-large ordinance is other capital ships, but then they're the type of target where "spare no expense" already definitely applies and you would be perfectly right to expend expensive large subsonic/supersonic/hypersonic cruise missiles, heavy and superheavy torpedoes, DF-21D/26s and LRHW type missiles.
Even if one accepts the need for super-large naval guns, twelve 18"s is insane, even for the Imperial Japanese who might have considered such a payload for their Super Yamato battleships. Even if you didn't use Yamato/Montana-level passive protection schemes, such a number of heavy guns would likely require greater than 40ktons of ship just to have mounts and a ship that can survive the blast and carry 100rpg, and mass would increase significantly if you want these to be autoloaders. There's also the fire-distribution issue; unless you have a comically long ship with twin or even single mounts you're likely packing four turrets maximum, so you're not engaging more than 2-4 targets at a time.
Do note that the reason for >6 large calibre guns for dreadnought-era combatants was due to need for uniform and sufficient splashes to help estimate range, then to ensure at least one hit against large targets (i.e. other battleships) quickly. This probably does not apply as much now in the era of modern radar and optical fire control.
The primary mission is not NGFS, I did not make that clear. The mission is strike and the warship complements existing cruise missile capabilities.
The Ukrainians and Russians regularly intercept each others' cruise and ballistic missiles at high rates, so China could certainly shoot down very large numbers of subsonic, non-stealthy Tomahawks. Passive surveillance will likely spot the incoming strike package soon after launch and allow interceptors to gather. Tomahawks can be shot down by cheap and numerous heat seeking missiles on their way to target, and gun or missile GBAD will take a toll as well whenever they fly too close. Then they'll suffer further attrition in the terminal phase. Overall, a package of hundreds of missiles might be required to actually impact the target with 50+ missiles.
The enemy has more than one target, and they will be making repairs. You don't hit an air base
once, you hit it
once per month. If the stockpile count of 4,000 missiles is to be believed, and US production is indeed currently <100 per year, then we'll blow through all of it in very little time--weeks if we really try. Adding more missile production isn't the solution, missiles are just too expensive to engage large numbers of protected, hardened targets. Guns, on the other hand, are much more affordable to feed, and that is the role of a large gun-armed warship.
So I think the mission profile looks something like this:
18" gun battery fires saboted 12" shells. Range of approximately 180km, GPS guided, bursting charge of approximately 80lbs. I'm not an engineer, I'm just loosely basing this on the USNSFA concept described
here, but I thought the given bursting charge was optimistic, so I reduced it to the 80 lbs bursting charge of the historical 12" HC Mark 17. If that description is believable, then a saboted shell fired out of an 18" gun should be capable of even longer range or larger payload.
Approach to 180km away from the target (naval base, air field, beachhead, whatever you're destroying that day). Volley the 12 guns as fast as you can. 180km is pretty far, and you have AAW escorts plus SeaRAM and Phalanx to catch incoming, but there's no reason to dilly dally. The Mk7 could manage 2 RPM, I'm going to humbly suggest 1.5 RPM sustained--the barrels might have some level of active cooling or at least improved materials science. A 30-minute bombardment would sling 500 shells per ship. Explosive effects are complex to model, they can't be boiled down to just comparing weight of filler--the crater of a Tomahawk with 250 lbs explosive filler is comparable to or smaller than a 16" HC shell with 150 lbs of filler, because thick shell walls concentrate energy to create a more complete detonation, and I suppose because the kinetic energy plays some kind of role. But, regardless, a 3-ship mission could deliver a
lot of effects, seriously damaging the targeted facility. As usual, complicate the repairs by mixing in 200 or so remote mining shells, with ~100 submunitions each.
The value proposition here is cost, so let's look into it.
A 16" HC shell in the 1940s probably cost the equivalent of $70,000 in today's money. That might not be perfectly accurate to say, as the number is just a straight transcription of the cost in 1940 in line with inflation. We've made advances in manufacturing since then, everything has gotten cheaper to make. A modern dumb 155mm shell only costs $1k-$2k, so that would put a 16" shell at 20x the mass and 35x-70x the cost. Curious on others' thoughts, whether anybody has a good source on price, once you get the production lines running and economy of scale benefits. For now, though, let's assume a cost of $70,000 for the basic shell, and similar costs for smaller shells due to increased complexity with the sabot.
GPS-guided Excalibur costs $70,000 and the overwhelming majority of that is going to be the guidance kit. Mounting the same technology on a much larger, roomier shell is going to make it cheaper--estimate $50k for guidance tech, so $120,000 total. Furthermore, precise GPS navigation isn't really needed, we just need to keep the CEP down to 300-500 yards at 180km range, not <5 meters like Excalibur. So guidance is needed until the last 30 miles or so, still pretty high in the ballistic arc, at which point it cuts out to make it jam/spoof resistant.
So this mission would cost $180,000,000 in offensive munitions, the same as ~50 TLAM. It delivers as much explosive filler as 480 TLAM, assuming no interceptions in both cases, but explosive filler isn't the whole equation so the effects would be even more superior for the shells. The interception rate would be much lower for the shells. If guidance kits can keep CEP below 500 meters, the number of hits on an area target like a naval base or airfield would be identical.
The major downside is that the guns have to approach much closer than the missile launchers would. However, that's what navies are for. The mission is going to need escort by many ASW frigates, stealth counter-air to kill enemy recon, attritable drones for counter-recon, Aegis destroyers for terminal defense, and likely 2-3 carriers for air and missile interception. Preparing the battlefield by throwing VLRAAM and CPS at anything that radiates will reduce the enemy's ability to detect the force. The task force should be designed for 30 knots while in the hot zone to further minimize detection chances.
Not the only strike option the USN should have. But it should be one of them.
