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Disrespect hydraulics at taxpayers’ peril

By Ken Korane | June 25, 2018

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Let’s face it, fluid power is not considered avant-garde or flashy. But it’s rugged, precise, safe, economical and, for decades, has proven to run reliably. That message has been lost on the U.S. Navy, which has spent a staggering $13 billion on its newest aircraft carrier, the USS Gerald R. Ford. The ship launched 25% over budget and three years late, in large part because designers made the ill-advised decision to replace time-tested fluid power systems with cutting-edge—and expensive—electrical motion systems that, to date, don’t work as planned.

Carriers are built to launch aircraft, a task steam-pneumatic catapults have done admirably for years. A shuttle connects the aircraft nosewheel to a piston in the deck, and opening a valve lets high-pressure steam push the piston down the deck and accelerate a plane fast enough for take-off.

The Ford’s new Electromagnetic Launch System (EMALS) catapult was touted as being lighter and more durable than steam units. EMALS stores an enormous electrical charge in four heavy flywheel-generators and then quickly releases the current into massive electromagnets that propel the shuttle down the track. Unfortunately, its immature technology has not lived up to its promise. The system thus far fails about once every 450 launches, 90% worse than the 4,100 launches expected per specifications.

Of course, jets need to land, too. Carriers have used hydraulically braked arresting systems since the 1960s. A hook on the landing aircraft catches a cable on the deck which, in turn, pulls the rod of a hydraulic cylinder inside the ship—essentially acting as a large shock absorber. Displaced fluid meters thorough valves to dissipate energy and bring the aircraft to a controlled stop.

Yet on the Ford, an untested Advanced Arresting Gear electrical system replaced the hydraulics. The pull of the deck cable spins a paddlewheel inside a cylinder of water, connected to a large induction motor, to provide braking force. Reliability is so poor that it fails every 25 landings, 660 times fewer than the Navy’s requirement of 16,500. And the original price tag of $172 million has now ballooned to an astounding $1.3 billion.

Making things worse, these systems can’t be electrically isolated, so crews can’t repair a catapult while continuing to launch planes from adjacent ones, which is routine on other carriers. Now, repairs have to wait, or all flight operations must stop.

And the Navy just announced it will need another $120 million, in part to fix the electric linear-motor Advanced Weapons Elevators, used to move munitions to the deck. Previous carriers’ elevators use—you guessed it—hydraulics. None of the Ford’s weapons elevators are operational, but a couple are being tested to identify other “developmental issues,” said DoD officials.

The new catapults, arresting gear and weapons elevators are all mission critical, but the propensity for breakdowns restricts the ability to launch sorties and makes the ship more vulnerable. Based on current poor reliability estimates, the ship is unlikely to be able to conduct the type of high-intensity flight operations expected during wartime, said a report from the Pentagon’s Director, Operational Test and Evaluation.

The Navy and defense industry have rushed ahead with fragile, unproven technologies that cost more yet perform worse. For all those billions, Congress should demand that our service men and women have equipment that works.


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