Having produced the privately designed Spruance class and its
Ticonderoga offshoot, Litton Industries (Ingalls Shipbuilding) offered
the Navy an alternative to the evolving DDX. This 1980 sketch shows
the firm's DDM (destroyer, missiles) proposal. Like DDX, it offered
the Aegis system with vertical launchers in a less expensive hull. A
May 1980 Ingalls brochure described DDM as a variant of the final
Spruance-class destroyer, USS Hayler (DD 997). This design was
compared to a 6000-tonner {note: info of which is omitted here -
erik_t}, which was presumably the DDX variant then under
consideration. Both ships had two 61-cell vertical launchers (106
Standard Missiles and 16 Tomahawks)... DDM had a 5-inch gun (aft) plus
2 Phalanx for close-in defense... each also had Mk 32 torpedo tubes,
but only DDM had reloads. The DDM combat system was based on Aegis...
DDM had the existing Aegis system... DDM would use the standard type
{of SQS-53}. Each ship was powered by three (rather than four of a
standard Spruance LM 2500 gas turbines, for a sustained speed of 29
knots (range 5000nm)... DDM did not {use integrated electric drive}
(its most economical mode, with only one turbine running, required it
to trail one shaft)... 6900 tons (529' waterline/563' overall x 55 x
15 ft; displacement was also given as 5859 tons light and 7145 tons
fully loaded, compared to 8040 tons fully loaded for Hayler) for
DDM... DDM could accommodate two {helo} parking spots. Litton also
claimed that its design offered far more growth potential (30-40
percent vs. 10-15 percent in payload). Estimated cost in FY 80 terms
was $187 million for a lead ship and $130 million for a follow-on...
compared to a Spruance, DDM offered better survivability and better
fuel economy. Survivability improvements included relocating CIC to
the hull, all-steel construction, and some armor (about 50 tons of
HY-80). This sketch does not quite match the May 1980 brochure, in
that it shows a pair of 3-inch guns (no 5-inch). There are also three
rather than four illuminators (in the May 1980 version, the fourth
illuminator was placed atop a lattice foremast, where the sketch shows
a pylon). In the May 1980 version, the ship has a Phalanx forward
where the 3-inch gun is in the sketch, the other being abaft the after
uptakes; the 5-inch gun is right aft, abaft the helicopter platform.
In the sketch, the helicopter platform has been relocated to the
fantail, presumably to shorten the ship.