UNITED STATES COAST GUARD (UNITED STATES OF AMERICA)

Project history: These large high-endurance cutters were among the first US warships lo be powered by gas turbines, Pratt & Whitney FT 4As in a CODOG (Combined Diesel or Gas turbine) system. Such propulsion was specifically justified by the combination of high endurance (I4,000nm at 11kts on diesels) and high maximum speed (29kts on gas turbines, with a range of 2900nm), the latter to run out to the scene of a rescue. There is also a retractable bow manoeuvring unit, described as useful for some oceanographic work. The unusual twin-funnel arrangement can be traced to the desire to place the helicopter pad at the most favourable point in the ship from the point of view of ship motion, about three-quarters of the way aft. The price paid is the narrowness of the hangar, which can accommodate only one HH-52 turbo-shaft helicopter. In the Perry class, a very similar configuration was originally selected (albeit with one rather than two shafts), but the uptakes were amalgamated when the design was altered to accommodate two helicopters: the hangar had to be widened and the helicopter pad consequently moved right aft.

    The design originally called for a Hedgehog superfiring over the single 127mm/38 gun forward, but Hedgehogs were removed from those ships which had them; all have the standard pair of triple Mk 32 lightweight torpedo tubes controlled by a Mk 309 Panel.