With the Mahan class, American manufacturers resumed development of destroyer machinery. General Electric's impulse turbines, also called Curtis turbines, worked with double-reduction gearing. This allowed smaller, faster turbines and left enough hull space for dedicated cruising turbines. Boiler economizers used heat more efficiently to heat the water, reducing the energy wasted from burning fuel oil. Together, these changes improved fuel economy and pushed range to nearly 7,000 nautical miles at 12 knots. Five 5-inch/38 guns and twelve torpedo tubes gave the ships a powerful mixed armament. These ships had several years for their crews to work up before the Pacific War. They fought through campaigns including Guadalcanal and Leyte Gulf, with six lost in wartime service and two later expended in Operation Crossroads.
Chapter · 41:35-46:58
Mahan restored domestic machinery development and Pacific range
Smaller, faster turbines left space for cruising turbines, while boiler economizers reduced wasted heat. These changes helped the Mahan class approach 7,000 nautical miles of range at 12 knots.