Todjaeger
Potstirrer
Actually the original plans for the Mk 41 VLS anticipated replenishment at sea. The realities of handling ordnance of that size and weight while underway in open waters intruded though and it was deemed unfeasible (at least with a reasonable level of safety).I can appreciate the value of VLS systems,
High rate of fire, likely convenient on the drawing board to have neat vertical boxes in your design.
But really, we have VLS because that's simply where the thinking is at the moment.
Whatever loadout we guess is loaded, in expected practice you would imagine that they should never ever intentionally all be used.
The ship needs to leave the AO, and dock in order to re-arm.
So for that return transit, to avoid being a lame duck, a (you would guess) reasonable percentage of munitions would need to retained.
Simply because, no one (as yet, that I'm aware of) can be bothered dreaming up a solution to reloading on the ship itself in the AO.
I think of the Mk13 launcher, it has a magazine of 40.
How much space does that take up?
What about a Mk13 fore AND aft? = magazine of 80 rounds, how much space does that dictate.
Perhaps, for munitions that will not require rapid rate of fire reactions we could use Mk 13s and leave the VLS dedicated for the quick stuff?
Thoughts?
As for VLS... These systems exist at present because they are viewed as superior to older missile launching systems like the magazine-fed Mk 13 launcher. Aside from a VLS having a potentially faster launch rate, is also eliminates many potential points of failure that exist in mechanisms like the Mk 13 launcher. A electrical or mechanical failure in the feed system within the magazine below decks could occur and keep the entirety of the magazine out of action. In a VLS, that sort of failure would most likely only impact a single VLS cell.
There is another mindset problem people have with respect to a high number of VLS cells though. And that is what is the relevance in acquiring so many VLS cells, or even the potential capacity to fit so many VLS cells, if there is a never a plan to use them. I readily admit that I do not know the state of the RAN's SM-2 Block IIIA or ESSM warstocks. I would not be surprised if it was sufficient to arm every RAN vessel fitted with the appropriate launchers and then have some available in reserve to reload at least some of the vessels. That would mean in the neighborhood of 80+ SM-2 Block IIIA, and 320 ESSM, then some additional missiles for the reloads (does not include the AWD's since they have not reached FOC yet). Given the 128 VLS cells available on a single Sejong the Great-class DDG are greater than the VLS capacity of all the ANZAC-class FFH's and Adelaide-class FFG's combined...One of the big mindset problems I think people have is that if you build a ship capable of being fitted with 128 VLS then you must immediately fill it with 128 VLS. Personally I am good with the idea that Australia buys a ship the size of the Sejong the Great and just equipping it with 48 VLS. The old adage of steel being cheap and air being free is true enough ... so long as you leave those spaces full of air.
Having a ship that size will of course leave you with a lot more options in the future.
In some respects it would be nice if some RAN vessels could fit 128+ VLS cells, but not if that would mean most/all other RAN vessels are essentially unarmed & defenceless. IMO a primary justification for and driver of additional VLS cells for RAN vessels would be the entry into RAN service of new (to the RAN at least) VLS-launched munitions. Examples of what I mean would be weapons like ASROC (which IIRC the USN is working on developing a newer version to carry a Mk 54 LWT) and/or LACM's and the situation would be not unlike that of some USN Arleigh Burke-class DDG's where IIRC approximately half of their 90- or 96-cell VLS capacity depending which build flight is for air defence missiles, with the rest for ASW or land-attack roles.
EDIT: Just saw Alexsa's post on VLS which went up while I was composing mine.