DD 963 class upgrade intention (long)
January 2nd, 2009 From
>Date: Mon, 18 Aug 1997 15:17:16 -0700
>From: Mike Potter
>Reply-To: mike.potter@artecon.com
>Organization: Artecon, Inc.
>X-Mailer: Mozilla 3.01Gold (WinNT; I)
>To: mahan@microworks.net, trooker@CAPACCESS.ORG
>Subject: DD 963 class upgrade intention (long)
>Precendence: bulk
>Sender: mahan-owner@microworks.net
>
>This analyzes an interesting note (snipped herein) that Tracy Johnson
>forwarded from the CONSIM-L list while I was on vacation . . .
>
>-snip #1-
>The Spruance was designed to take advantage of several programs then
>under development. All of these were part of the original plan. the
>Spruance was designed to have 2 8″/72 mounts replacing the 5″/54s.
>Although some people claim that only one was intended. I had a friend
>who was a gunnery officer on a DD963 and he told me the figures
>comparing the magazine loadout of 5″ shells on his ship. Considering the
>difference in size of the 8″ and 5″ rounds I believed him when he said
>they were supposed to have 2 8″ guns.
>-end snip-
>
>Comment: DD 963 spec was actually for just one 5″ mount to be replaced
>by an 8″ or 175mm mount. In Litton’s winning design, only the forward Mk
>45 5″ mount (Mt 51) location had enough hull depth beneath it for a Mk
>71 8″ mount. I doubt that the Navy would or could re-design the Mk 71
>mount to fit in the aft 5″ (Mt 52) location, because:
>- The 8″ mount would need more depth for the loading tray to swing down,
>and also would need a higher loader tube for the longer 8″ round. If the
>Mk 71 mount were raised to the 01 level, it would block the Sea Sparrow
>launcher.
>- Retaining a 5″ mount aft would still be valuable because it would hold
>more rounds (600 vs 250 in the forward-8″ plan), and because of the
>greater variety of 5″ ammunition types than of 8″.
> BTW: When VLS was installed on DD 963 ships, retaining the margins
>for Mk 71 or another mount was not required. The ships had to be
>ballasted to compensate for the VLS weight, making a heavier-weight gun
>mount forward unattractive since then.
>
>-snip #2-
>The ship was also designed for the VLS. It just wasn’t available when
>the original ships were built. That is also why the Shah got the Mk26
>(?) luanchers for SAMs, it was the only thing ready at the time. The
>DD963 VLS was intended to carry more than THAWK though. The were vague
>intentions for a vertically launched ASROC, possibly a VL Harpoon, and
>some SAM. I think the intention for the latter was to have a
>multi-channel FCS that could be used to gunfire or to guide 1 or 2
>missiles. Presumably this would have been some variation of the Standard
>missile. They only became Strike DDs when all the programs but THAWK
>lapsed.
>-end snip-
>
>Comment: The ships were designed (1968-69) for Mk 26 twin-arm launchers.
>Mk 41 VLS launchers were developed in the late 1970s and went into
>production in the early 1980s. Even had VLS been available for the
>Shah’s cruisers, Standard SM-1 missiles were not VLS-compatible.
>- Mk 41 VLS was designed to be compatible with Mk 26 so it was an easy
>retrofit in the Mk 26-compatible DD 963 design. In fact, the US Navy
>plans to replace the Mk 26 launchers on the first 5 Aegis (Baseline 1)
>cruisers with VLS.
>- The original VLS design was too shallow for Tomahawk. SecNav Lehman
>cancelled VL-Harpoon and pushed a deeper VLS to push the Navy toward
>Tomahawk. An early Tomahawk variant was an anti-ship missile (TASM), now
>withdrawn for reasons of obsolesence and policy.
>- VL-ASRocs exist and are issued to deploying VLS ships. They carry Mk
>46 torpedoes only, not Mk 50 or nuclear depth charges.
>- A VL SAM system for the DD 963 is technically feasible but
>development has never been considered cost-effective. Several DD 963s
>are getting rolling-airframe missile (RAM) launchers to upgrade their
>air defense capability. The launcher is installed on the starboard
>quarter.
>
>-snip #3-
>The beamy hull of the Burke class has little to do with future growth .
>. . The Soviets had consistently built ships that were much beamier,
>because there were some drag resistance benefits at high speeds.
>-end snip-
>
>Comment: It’s correct that the “broad waterplane” hull design of the DDG
>51 class is not primarily related to growth margins, but speed isn’t the
>advantage. The broader hull is theoretically fuel-inefficient at high
>speeds but with gas turbines you can’t achieve the theoretical ideal
>anyway so there’s no real loss. What’s important about the broad
>waterplane design is that it greatly improves seakeeping, which the Navy
>noticed in broad-waterplane Soviet warships. The Navy wanted an even
>wider hull (by 2 feet) than the DDG 51 actually has.
> BTW: Gibbs & Cox’s competing DD 963 design was beamier than Litton’s
>winning design with an identical power plant. A former Litton designer
>has stated that Litton’s narrow-hull design resulted from a towing-tank
>test interpretation error. OTOH Litton’s ships are faster than the Navy
>required.
>
>I have sources for all the above if anyone is interested. I liked seeing
>the post from trooker@CAPACCESS.ORG and am pleased at the interest in
>the DD 963 class.
>
>–
>Michael C. Potter, Mgr, TelCo/Govt Programs mike.potter@artecon.com
>Artecon, Inc. | | mail PO Box 9000
>6305 El Camino Real -|- _|_ Carlsbad CA
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