The U.S. Navy is adding a hybrid-electric drive to its 34 newer Arleigh Burke-class guided missile destroyers, in essence turning them into floating Priuses. Hybrid drive cars, like the Prius, use batteries that are recharged by the conventional engine and that allows the use of more efficient (under certain conditions) electric motor. On the Burkes The added electric motor will help propel the ship at speed of up to 24.1 kilometers per hour, speeds at which the four LM-2500 gas turbines on the ship have much less efficiency. The gas turbines are most efficient at high speeds, but a lower speeds waste a lot of fuel compared to diesel and electric drive. The hybrid electric drive for ships is not new and was first used in submarines during World War II.
When the Burke program began in 2008, the Navy was driven more by high oil prices (well over $150 per barrel). While the price has dropped (to $40), the Navy is continuing the program. In this case, the green technology will actually make a lot of sense operationally. In this case, the hybrid drive will buy 60 more hours of on-station time between at-sea refueling. That eases the burden on replenishment vessels – and also allows the Navy to keep an eye on trouble spots a bit longer. The Navy plans to install the hybrid drive on the first two Burkes in 2015-16.
An Arleigh Burke-class destroyer displaces 8,315 to 9,800 tons, and can travel at a top speed of over 56 kilometers per hour. They carry a five-inch gun, 90 or 96 cells in Mk 41 Vertical Launch Systems, two triple –mounted 324mm torpedo tubes and the newer Burkes can carry two MH-60 helicopters. The ships use the AN/SPY-1D radar system to locate and track aerial targets.
The U.S. Navy has 62 Burke-class destroyers in service. Japan has another six in service, while South Korea has three in service. The United States is building another six vessels with plans to build at least seven more, while South Korea has three under construction, and Japan is considering adding up to four more. – Harold C. Hutchison