carr wrote:
SumGui wrote:
Weight and simplicity is one of the main reasons I am leaning toward the Mk57 PVLS fit. VLS cells on edge of the flight deck should be pretty evenly distributed (I am currently envisioning 3 or 4 4 cell modules per side) and of course actual weight distribution will be finalized by actual loadout. The forward position seems able (by rough eyeball calculation...) to take 8 Mk57 (4×2).
The weight and stability issues on LCS-1 class are fairly well known. As you indicate, the weight and stability issue of LCS-2 class are less known although my understanding is that both classes have minimal weight margins. I'm guessing that the LCS-2 class does not have the same stability problem due to the trimaran design. The LCS payload capability is around 200 tons.
A single Mk57 4-cell module weighs 33,600 lb. With associated electronics, call it 35,000 lb. An SM-2 weighs 1558 lb.
So, for the max of 10 modules, as you describe, the Mk57 weight alone would be 350,000 lb or 175 tons. A loadout of SM-2's would add 62,320 lb or 31 tons.
So, 10 loaded Mk57 modules would add 206 tons.
Add in the various other weapons and whatnot plus, presumably, some extra crew to operate things and you've well exceeded the available payload capacity. The changes you're describing would undoubtedly require some structural reinforcement to physically support the cells plus lots of additional piping and wiring runs for extending the ships utilities to support the VLS - all adding significant weight. I'm guessing that additional bulkheads would be required between the cells and the ship's internal spaces, possibly armored - that's the whole point of the peripheral cells - to minimize internal damage in the even of a hit - yet more weight.
Can the LCS-2 class absorb that kind of weight increase? I don't know but at the very least it would be a challenge even if possible.
My point is that we need to be careful before we begin sprinkling additional weapons all over the ship if we're trying for realism. For a modelling "what if", hey, sprinkle away!
For example (to make up an absolutely silly change), adding a Mk71 8" gun to an LCS is an example of a totally unrealistic modification. The LCS is far too weak structurally to handle the weight and recoil. The first shot would probably rip the bow off. I would be foolish to think I could add an 8" gun just because the footprint was available on the deck. Even adding a 5" gun would require structural reinforcement and is probably not realistic.
Have fun with the modifications but be cautious if you're going for realism!

Thanks for the numbers, looks a lot like what I'd put in the Spruance thread for fun...
200 tons seems unreasonably low for the size and stability of the LCS-2 design, if true, it reenforces my desire to see these vessels recycled ASAP...One way or the other that number may need to be fudged upward to add utility (and I'm fine trading off some of the 44+ kt speed once they get weighed down). Do we know if that number is mission module payload, or total available on the platform? I'm going to go forward with the assumption that 200tons is the number the mission modules have to meet. I do not have as much concern about reduced stability on the trimaran due to overweight as I would on the monohull.
Getting 6 Mk57 modules (201,600-210,000 empty) by given weight estimates may be more plausible, a quad packed ESSM cell adds 2480lb (620lbs each RIM-162) each cell so loaded. So, assuming 8 cells quadpacked with ESSM, and using 2000lb/1 ton as a weight analogue for the other 16 cells, we get 261,840lbs (210,000 empty Mk57 + 19,840 for 32 ESSM + 32,000 reserve for the other 16 cells), or about 132 tons.
The existing 35mm version of the Millennium Gun in turret is 3300kg (probably empty of ammunition, but hey, it's what I've got...), or approx 7275lbs. Two of these will cost approx 15000lbs, or about 7.5 tons. lets up that to 9 tons just to account for ammo and spares.
So right now it sits at 141 tons added (of the estimated 200 tons available), clearly there will be some additional weight in structure to support the fit, and the added crew for operations of the weapons, all which I don't see as out of the realm of possibility.
As a separate item, the Archer Mobile Gun System sits at an estimated 66,000lbs - however that includes the truck chassis, and all of its weight as well. Assuming the truck chassis, engine, and armored cab are roughly equal to the weight support needed if mounted on the LCS-2 (marinization, mount to the vessel, ammunition - and i think this overestimates, but then, we do have to consider a couple of crew additions...) we would get about 264,000lb, or 132 tons. Yes, I know that is a SWAG. As I don't intend the Archer item to be a common or consistent fit, is it acceptable/plausible to have both of these items aboard? 141+132 puts us at 273tons, and with some slop room for support additions we sit within the realm of 300tons total for the whole shebang.
Accurate? No. Perfect? No. Plausible? Sure. Doable? Probably.
Especially the MGs+Mk57.
Thanks for the help.