DD

↑By 1966 it became apparent that the many of the missile ships converted from World War II cruisers would soon have to be retired. Therefore a new class of missile ships was required. at the same time the end of the DE-1052 program was in sight and a new (ASW) escort ship program had to be restarted. for 1968 the secretary of defence requested a contract definition for a new guided missile destroyer or escort, designated DXG, and also for a new ASW escort, DX. It was observed that 'joint funding will permit investigation of the desirability of various degrees of commonality between the DX and the DXG'. From the beginning, the new program was seen as an major fleet escort, which those days meant missile escort. The DXGs had to replace the missile cruisers and partially the DEGs, which were seen as marginal at best. The DX was seen as an ship propelled by the new gas turbine. At this point the DX was seen as little more than a DE, hardly fast enough for carrier operations. However, in the fall of 1967 it was suggested that there were enough DE types, but there was a need for 30-knot ASW ships with better guns than the DE. DX and DXG would at this point not share more than some systems, but would complement each other in the carrier escort fleet. There were less AA launchers required then ASW screen ships, so some fast DX ships could replace some of the current missile ships in the formation. The 1966 OSD concept called for 18 DXGs and 75 DXs in FY 69-74. One of the options was for the 2 classes to share identical hulls, and differ only in weapon systems. This would maximize standardisation and would take benefit from the economics of large scale production. However, if the DX would grow to such sizes that it might still be preferable to keep the classes separate. A common hull would facilitate modular construction though, in which the systems would be nearly ready to operate when installed in the hull, making it easier to build and to modernise the ships in later years. The procurement of these vessels would be on a total package basis, with a single private contractor creating the design and then building all units. The ships were to be designed with modernisation in mind, so there were margins for future growth ready in the design. This was something entirely new in warship design back then. Such an modernisation would occur about every 10 years. After it was decided DX and DXG would have the hull in common, was conversion. In case a thread would arise in which DDGs were more valuable than DDs, the DXs were to be converted to an 'AAW Area Defence Escort', in other words a frigate. On 23 September 1966 a special study group called for a five year program of 18 DXGs and 85 DXs to replace 250 elderly escorts. The first units would have to be ready in 1973. In this study was the DDG FY67, mentioned above, which was the latest design available, and the DX would be an 'deconverted' DXG, reduced to DE-1052 standard of weapons. In June 1967 a new study was done which looked at what capability was needed. Out of this was concluded that there were to be ASW/shore support destroyer (DX 2) and an AAW/ASW DDG (DXG 1) respectively 40 and 20 were seen as needed. The requirements for the DX/DXG were finally set in January 1968, calling for: - CVA escort. - two guns for fire support. - sustained speed of 30 knots in sea state 4. - 6,000 nm endurance. - ASROC. - the conversion from DX to DXG had to be simple and economical. - DX would have helicopter facilities, DXG only a platform. Image courtesy of Shipbucket.

↑The procedure followed by the navy was to sketch a series of notional ships (baseline designs) that would test the feasibility of the proposed performance standards. Only those standards would be transmitted to the bidders in the form of requirements. These studies indicated quite early that the DX would be an exceptionally large destroyer. The reason for this is not hard to find. Although the DX had roughly the DE arnament, it had to be converted to be a DDG, which was by now very close to an frigate. That meant the DX would in size be close to an DLG. In addition, the combat system fitted in DX was to be the one developed for Seahawk, which would drive up cost without providing an obvious increase in weapons or firepower. Current experience also learns that modular construction adds size as each space has to be slightly bigger than what actually fits in. Had the systems not driven size though, the outcome would still be an very big ship. This was because of the speed requirement in sea state 4, which could not have been done by an much shorter ship. Still, the greatest driver for size would be the conversion to DXG. At first this entailed an quite austere DDG, replacing the Mk. 16 ASROC and one 5in/54 by an single arm launcher for both tartar /ASROC launcher (Friedman notes that even the Mk. 22 was suggested, but this, as is known, cannot fire ASROC) it was estimated by NAVSEC that such a ship could be had on about 5700 tons, light ship. These designs are following the drawings by A. D. Baker III but had no measurements given. These are thus scaled by their various parts and compared with the final DX designs for reference. They might be off, but they should be pretty close. Notional ship B (ASW) shows very well how 'empty' the DX was proposed to be. Interesting is that SPS-49 was supposed to be placed (Spruance had SPS-40), Mk 25 sea sparrow launcher (Spruance had Mk. 29 NSSM) and the remote optical sight of the Mk. 86 FCS (instead of the SPG-60 with the optical sight on it) the ship is also steam driven. Image courtesy of Shipbucket.

↑Notional ship B (AAW) seems to not fill the requirement for the DXG, as it no longer has a helideck. However, the empty stern might make helicopter operation possible. This drawing was also the only one having a ECM system specified, named 'Shortstop'. Image courtesy of Shipbucket.

↑This design is the most interesting. It is not mentioned in the text. The ASMS system fitted on it is, according to Friedman, in this setup only possible to be fitted on a DLG(N) and this design seems to prove otherwise. The ASMS system was supposed to be fitted inside 2 deckhouses which would be installed as late as possible in the construction process. Only the CIC equipment would stay out of these deckhouses. On the ship is also an unknown launcher, and an unknown missile which I have represented by Tartar here. It is unknown if at this stage the missile would be developed new or based on 3T, as was done in AEGIS. The radar on the aft mack is also unknown. It is interesting to see that this ship is the only ship with a different hull then the others. Even the DX 2 (shown underneath this one), while not part of the same series, is represented by the same hull as the ones above. Image courtesy of Shipbucket.

↑Notional ship DX2 is similar to notional ship B (ASW) except that it uses the common launcher, also known as Mk. 26. Note that the forward gun is not the Mk. 71 but the 175/60 gun developed for the LFS (fire support ship) most likely this ship was part of another series, as I suppose there would have been an DXG with the Mk. 26, but I have found no references for this and thus have no drawing of these designs. Image courtesy of Shipbucket.

↑The notional designs were not shown to the yards, but were used to set a benchmark for the yards. the designs the yards supplied would be judged by comparing them with these. Littom won the contest, with the 3-gas turbine design shown below. Bath Iron Works on the other hand lost, but it is interesting to compare what they came up with. Image courtesy of Shipbucket.

駆逐艦