The Ship Model Forum

Two AGS mounts on a Spruance hull.

Based on Data from:
http://dspace.mit.edu/bitstream/handle/ ... BStudy.pdf

There were three options proposed, and one more mentioned.

Option 1 was remove VLS and Mount 51 for an AGS forward
Option 1 Ref drawing: http://www.shipbucket.com/images.php?di ... on%201.png

Option 2 was remove Mk 29 Sea Sparrow and Mount 52 for an AGS aft
Option 2 ref drawing: http://www.shipbucket.com/images.php?di ... on%202.png

Option 3 was as option 2, with an additional deck house where 52 used to be for more ammo
Option 3 ref drawing http://www.shipbucket.com/images.php?di ... on%203.png:

Option 4 was AGS forward and aft.

Much of the paper covered the operational capabilities provided by the pre-refit platform, and the author clearly believed that Tomahawk was a critical asset to the vessels. The loss of Tomahawk and VLASROC is why the author chooses Option 2; Option 3 was eliminated due to weight aft; and the electrical load required for two AGS led him to drop Option 4.

I’d like to pick up option 4.

In so doing, I say losing one more Tomahawk shooter in a group is really not that big of a deal; there are plenty of other VLS cells out there, no other platform has NGFS capability like this, so it is a net add to a battle group by increasing capabilities. VLASROC is lost. Everything has to cost something...

For the sake of this exercise, I’ve replaced the SSGTGs. In order to take the increased electrical demand of the AGS systems, I have the SSGTGs replaced with the RR AG9140 SSGTG (3000kw), which is what is fit to the DDG-51 Flight II starting in 1998, so it certainly would be available.

This re-levels the theoretical electrical load of the ship to pre-refit levels. 3600kw availability and 2743kw load pre-refit (76.2%), 5400kw available and 4212kw load post refit (78%). This is based on two SSGTG online running 90%, leaving the third as backup – just as mentioned in the paper.

Clearly, modification to freshwater cooling for Mounts 61 and 62, and the fire main for mag sprinklers would need to be done.

Because the platform can be expected to need to position itself for best delivery of 155mm solutions, it can be expected to close the objective coast, leading to the need to increase small boat defense (the bombing of the USS Cole was in 2000, and would certainly be on the mind of the designers of this project in 2003/2004), thus the addition of four Mk38mod2 mounts.

And clearly, loss of Sea Sparrow is not acceptable.

Thus:

USS Thorn (DD-988) 2004-5 AGS conversion:

Forward:

Mount 51 and the Mk 41 VLS removed and replaced with mount 61, an AGS with 320 rounds. This is option 1 in the paper. Weight lost forward: -156 Tons

Mk48mod2 VLS with 32 RIM-162 ESSM is placed aft of mount 61, essentially where the Mk41 VLS was, but this is above deck, as the below deck space of the Mk41 is now AGS magazine. Weight of loaded VLS: +16 tons

Mk38mod 2 25mm chain guns are mounted abreast the Mk48 VLS, Port and Starboard. Weight of mounts: +4.5 tons

Net weight lost forward: -135.5 tons

(If space is available forward, I would consider adding Mk 141 Harpoon/SLAM canisters forward of the bridge. A forward FC channel for ESSM would also be a good add.)

Aft:

Mk 29 Sea Sparrow launcher and mount 52 are removed. AGS installed with 304 rounds. This is option 2 of the paper. Weight added aft: +237 tons

Removal of 153 tons of ballast added aft to compensate for Mk41: Weight lost: -153 tons

Mk38mod 2 25mm chain guns are mounted abreast the Helo pad on the Sea Sparrow deck, the same location used by the Ticonderoga Class. Weight of mounts: +4.5 tons

RAM on the fantail. (Already aboard, just mentioned for clarity)

Net Weight added aft: +88.5 tons

All other systems remain as-was aboard USS Thorn as of 2003 (CIWS, SPS-40, Mk23 TAS, SQQ-89, SH-60B, etc)

So she ends up light by the bows, needing ballast forward to trim properly.

This would probably be a very expensive refit, considering replacing the SSGTGs, all the deck work and re-arranging involved.

This melds into my alternate timeline I’ve posted elsewhere, as Thorn was not yet allocated to the LFS refit I envisioned (Mk 71 MCLWG), or the AAW refit I envisioned (NTU moved from decomming CGs to create near Kidds).


Mk 38 ref:
http://www.baesystems.com/cs/groups/pub ... 027609.pdf

Mk 48 Ref:
http://en.wikipedia.org/wiki/ESSM

AG9140 ref:
http://www.rolls-royce.com/marine/produ ... ag9140.jsp

Wish I was good a Shipbucket so I could make it myself.

Opinions? (no need to bash AGS here - we've done that enough...myself included)

Wow, that went over like an aluminum turd...

I guess i should congratulate you guys on listening to mom: "If you don't have anything nice to say, don't say anything at all..."

I plan to model a basic version of this in 1/700, and leave mount 61 and 62 unglued so I can change them out with mount 81 and 82 (Mk 71 MCLWG)

I need to get Mk 38 Mod 2, AGS, and MK 71 in 1/700. I've got the rest.

Uhhhm, where are you going to get a Mk 38 Mod 2 or a Mk 71 in any scale?

exactly my problem. I'm going to have to fabricate them, and the Mk38 is so small at 1/700, I may have to find some way to re-purpose photo etch from something else.

That will be interesting, at 1/700 the "eyeball", for lack of a better description, on the MK38 Mod 2 would be reeeeealy tiny, like sand grains.