China moves closer to electric propulsion for naval ships

Published By United Press International


BEIJING, Aug. 29 (UPI) -- China Shipbuilding Industry Corp. said it has finalized its gas turbine electric propulsion system for naval ships, China Daily reported.

CSIC's Wuhan Institute of Marine Electric Propulsion has been developing the system with a view to making China less dependent on foreign-made gas turbines that produce electricity to power vessels.

China Daily quoted Wang Dan, deputy editor in chief of Modern Ships magazine, as saying the technology is imperative for China to keep up with British and American naval propulsion systems.

"With the achievement made by our technicians, we are seeing an opportunity to narrow the gap with Western naval powers," Wang said.

"The British navy's Queen Elizabeth aircraft carrier and the United States Navy's Zumwalt-class destroyers, which are under construction, will use the new electric propulsion technology. We must accelerate our development [of the technology] if we don't want to fall behind in building advanced ships."

An integrated electric propulsion system uses a gas turbine or diesel generator to produce electricity that powers motors, which turn propeller shafts or operate waterjets.

The system significantly does away with heavy mechanical clutches and highly sophisticated gearboxes that reduce or increase power to propeller shafts.

Wang said an integrated electric propulsion system saves space and weight and is easier to control and maintain. It also is quieter to run and can increase a ship's speed over conventional diesel engines.

The China Daily report gave no details of the CSIC's turbine system.

Rolls-Royce announced in January that it had installed into the Queen Elizabeth aircraft carrier the first of two marine gas turbine engines.

The MT30, a 36-megawatt -- about 50,000 horsepower -- engine, was lowered into the hull under construction at Babcock's Rosyth shipyard in Scotland.

Rolls-Royce said two MT30s will be installed in the Queen Elizabeth and also in the sister Queen-Elizabeth-class carrier Prince of Wales. The two engines will provide two-thirds of the 109 megawatts needed to power the nearly 72,000-ton vessel, Rolls-Royce said.

The MT30s are installed as part of a gas turbine alternator system that, along with enclosures, weighs about 120 tons.

The Queen Elizabeth is scheduled for sea trials in 2017 and flight trials in 2018.

The vessels will be the largest ever for the British navy and will carry up to 40 aircraft, including Lockheed Martin's F-35 Lightning II fighters.

Rolls-Royce's MT30 powers the U.S. Navy's Freedom Class variant of the Littoral Combat Ship, will power South Korea's FFXII frigate and are destined for the U.S. Navy's Zumwalt-class destroyers.

Huntington Ingalls Industries, formerly called Northrop Grumman Shipbuilding, in Virginia, and Bath Iron Works in Maine are building the Zumwalt destroyers.

Rolls-Royce said the MT30 gas turbine is derived from Rolls-Royce's Trent 800 aircraft engine that powers Boeing 777, with about 80 percent of the parts being the same.

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