The U.S. Navy’s sophisticated and versatile littoral combat ships (LCSs) can chase down speedy enemy boats in shallow waters, hunt for diesel submarines in the open ocean and defuse mines at any depth. The Navy plans to build 30 LCSs, and half of them will be powered by a pair of GE turbines originally developed for a different branch of the military: the U.S. Air Force (more on that later). The Navy commissioned the latest one from the GE batch, the USS Manchester (LCS-14), on May 26, and eight more powered by GE are set to follow.
The Navy clearly likes the cut of GE’s jib — some 97 percent of its ships that use gas turbines rely on technology from GE’s Marine Solutions unit. And now the company hopes to lend its reliable engines to yet another new crop of ships. In February 2018, the Navy announced plans to launch 20 new FFG(X) frigates, carrying guided missiles and designed to be even more fearsome than the littoral ships. GE has offered to power them with the latest variation of its GE LM2500 turbine, which features a new lightweight carbon-fiber composite enclosure that replaces its heavier steel predecessor. This quieter and lighter turbine enclosure is less prone to corrosion, a key issue in the marine environment.
The new design and composite materials shaved 2,500 kilograms off the turbine and reduced noise by 60 percent compared with the older version. Now the cooler engine room below deck is a safer environment for sailors.
The first ship to use a GE turbine was the USS Spruance, commissioned in 1975. Since then, GE turbines have powered some 646 ships in 35 navies — from German frigates to South Korean destroyers, ocean liners like Queen Mary II and the Francisco, possibly the world’s fastest ship, capable of hitting 58 knots, or 69 miles per hour.
What’s the engines’ secret? They are relatively small — they can fit inside a space a little larger than a shipping container — but they also pack a tremendous amount of power. Each of the two GE turbines on the USS Cincinnati, for example, can generate 29,500 horsepower, propelling the ship to 40 knots, or about 46 miles per hour. “The key requirement for the LCS program is being able to hit top speed quickly,” says George Awiszus, senior product marketing leader at GE’s marine business.
The GE turbine is perfectly at home in the water, but its story began in the air more than 50 years ago. In the 1960s the Air Force tasked engineers at GE Aviation with developing jet engines for a massive new cargo plane called the C-5 to carry heavy cargo across the Pacific Ocean. Today, civilian versions of the engine power many Boeing 747 jumbo jets, including Air Force One, and other passenger planes.
In fact, the engines were so powerful and reliable that GE decided to look for other possible applications. The company tweaked their design, adapted them to burn natural gas, diesel and other fuels in addition to jet fuel, and used them to generate electricity. Today they produce electricity for companies and utilities all over the world, and many navies, shipping companies and even cruise ship operators use them to power their vessels.
Ships can use the GE turbines in several configurations: They can drive the propellers, like on the USS Manchester; they can generate heat and electricity, like they do on cruise ships; or they can do a combination of both. “It’s been all hands on deck for us for the last 50 years,” says Awiszus. “We like to keep it that way.”