Typhon DDG 47
With the ordering of the first 2 Typhon armed ships, the California class DLGN fitted with the AN/SPG-59, the new Typhon missile system was officially going to enter service in the USN. The complexity and cost of these ships however, was known to be considerable even in the early design stage. Not in the least this was because of the SPG-59 radar. The fact was, not enough Typhon cruisers and frigates were going to be build to fully exploit Typhons abilities in the fleet. The plan was that Typhon could be used by existing ships too, but without a refit this would offer next to no advantage over Terrier and Tartar. So, a second Typhon ship type was required by the USN. This ship would have to be considerably cheaper then the new California class design, which meant the new ship could not be nuclear. The ship would have to use existing or modified existing systems as much as possible, so it could be designed fast to enter service at the same time as the California class.
To realise this, the starting point of the design was the DDG FY67. The powerplant and basic arrangement of that design were used, meaning that the ship would get propulsion from 4 General Electric LM2500 gas turbines, of which 2 were placed in the engine rooms and 2 in deckhouses on the main deck level. The turbines on the main deck level were electrically coupled to the propeller shafts. This allowed efficient cruising (2 shafts on 1 gas turbine), silent running (during cruising no large engines or gearboxes were running inside the hull) and it allowed easy upgrade of the cruising gas turbines on the main deck to regenerative cycle gas turbines to make the ship even more efficient in the long run. The large free internal space in the engine rooms was used for better watertight subdivision and for the placement of generator sets to power the large electronic systems.
Different from the DDG FY67 were part of the weapons and sensor systems. The primary armament was the Typhon missile system, consisting of an Mk 10 Terrier GMLS Mod 5 firing RIM-50 Typhon LR(and RUR-5 ASROC) and an Mk 13 GMLS firing RIM-55A Typhon MR. 2 5''/54 Mk 45 guns were fitted, using the new Mk 86 GFCS for guidance.
Missile guidance was done by the second line Typhon B system, which used C-band advanced dish directors, based on the SPG-51, and AN/SPW-2 Missile Guidance Radars. Air search was done by the AN/SPS-48 while tracking and targeting was done by the AN/SPS-33B system, which was an smaller, lower power version of the SPS-33 used in the Hughes SCANFAR system. The radars were concentrated in a single deckhouse, so new ships of the class could use different radar systems if they became available, and even an refit of the early ships was not considered impossible.
For ASW, the ship was fitted with an AN/SQS-26 to guide ASROC and the self defence Mk 32 SVTT. ECM was done by an AN/ULQ-6 installation.
The ships were successful, but the system was not as capable as the SPG-59. This was not an real issue, as the ships were always meant to be an cheaper alternative, between 75% and 95% effectivity compared to the SPG-59 fitted ships (depending on conditions) was acceptable as the repeat ships costs were only 70% of that of the SPG-59 fitted DLGN's. 8 were build, of which the second series of 4 had their aft gun traded in for an small helicopter hangar, to give the ship more multirole capabilities. The first ship was commissioned in 1973, followed by two ships a year until the 8 were completed in 1977.
The DDG-47 had a length of 167.6m, a beam of 18.6m and a draft of 5.8m. The light ship displacement was 6600 ton and the ship was 8933 tons full load. The ship had an top speed of 30 knots and a range of 7500nm at 20 knots. She had a complement of 25 officers and 346 enlisted.
