Magnets vs. steam drives debate over future carrier catapults

President Donald Trump wants the Navy to go back to the future by restoring steam catapults to launch planes from aircraft carriers, a directive that critics say will cost billions of dollars, exacerbate construction delays and introduce logistical hurdles.

The national security memorandum that Trump signed Aug. 13 would end the use of Electromagnetic Aircraft Launch System, or EMALS, in future Gerald R. Ford-class carriers. The order directs Defense Secretary Pete Hegseth and acting Navy Secretary Hung Cao to deliver a plan to Trump within 60 days outlining the timeline and resources needed to make the changes aboard the fourth Ford-class carrier, USS Doris Miller.

“The United States Navy has experienced a series of shipbuilding setbacks stemming from overly complex designs and iterative design change procedures,” the memo states.

Magnets are out and steam is back in, Trump directed.

U.S. carriers use a CATOBAR (Catapult-Assisted Take-Off But Arrested Recovery) system. The 10 Nimitz-class carriers operated by the Navy use steam generated from the carrier’s nuclear power plant to fling strike fighters 300 feet in under three seconds. The aircraft accelerates from zero to 160 mph and into the air.

With EMALS, currently only in service on Ford, electromagnetic coils under the deck are used to accelerate the shuttle attached to aircraft.

The directive doesn’t call for tearing out existing EMALS systems.

USS Gerald R. Ford, commissioned in 2017, uses EMALS. So does USS John F. Kennedy, which is scheduled to be commissioned in March 2027.

EMALS would also stay in the USS Enterprise, currently being built at HII Newport News Shipbuilding in Virginia and slated for commissioning in 2030.

But beginning with the fourth Ford-class carrier, USS Doris Miller, the launch system would go back to steam under Trump’s memo. The Navy’s long-range plan is to add another six Ford-class carriers in coming decades, which would use steam catapults under the Trump directive.

So far, support for the return to steam has mostly come from within the Trump administration.

Jerry Hendrix, director of the shipbuilding office within the White House Office of Management and Budget, said in a series of tweets that critics of steam catapults aren’t considering “the hard math driving these considerations.” Hendrix contends that Ford-class carriers take too long to build because of complex designs.

Outside of the White House, Trump’s directive has faced widespread criticism.

Russell Vought, then acting director of office of management and budget, views USS Gerald R. Ford’s advanced weapons elevators during a tour of the ship in September 2019. (Connor D. Loessin/U.S. Navy)

Bryan Clark, a former Navy officer who is a senior fellow at the Hudson Institute, said retrofitting steam catapult systems into the design of future carriers would require expensive and time-consuming changes that “risks crippling fleet readiness — already at its lowest point in decades.”

Clark noted the supply chain and steam catapult production lines shut down after the last Nimitz-class carrier, USS George H.W. Bush, was commissioned in 2009. Restarting manufacturing would demand massive financial investments and extended lead times and delay the Ford-class program further.

Proponents say the EMALS system can be more precisely calibrated for the type and weight of aircraft being launched.

Whereas steam catapults jerk the plane down the deck when engaged, EMALS magnets both push and pull the shuttle, attaining launch speeds without the initial jolt. In the long run, EMALS proponents say it saves wear on both aircraft and the catapult system itself.

Under routine operations, Ford can launch 160 sorties per day during sustained 12-hour operations, compared with about 120 for Nimitz-class carriers, according to the Navy. That means three Ford-class carriers with EMALS can launch as many planes as four Nimitz class carriers using the steam system.

Adm. Daryl Caudle, the chief of naval operations, speaking last week at the Tailhook Symposium in Reno, Nev., said that during its recent deployment, Ford produced between 120% and 130% of the Nimitz-class sorties, according to Aviation Week. “We saw numbers in that that were as advertised,” he said.

Clark said changing the design at this point would push the delivery of Miller into the late 2030s.

“The Ford also has been costing the Navy $100 million less to operate per year than its predecessors because they replaced all the ship’s steam equipment with electrical,” Clark said.

With more electrical systems, the number of crew needed on the carrier is about 500 less than Nimitz-class carriers. Operating a steam catapult requires a crew of 12, while the highly automated EMALS system needs only two to operate.

Sen. Roger Wicker, R-Miss., the chair of the Senate Armed Services Committee, is a supporter of Trump’s $1.5 trillion defense spending plan. But he’s against abandoning EMALS, which is developed in part in Tupelo, Miss.

“I think there’s overwhelming support in the Congress and in the Pentagon for moving forward with EMALS,” Wicker said in an Aug. 18 statement.

Steam from the catapult envelopes a Navy F-14 Tomcat as the flight crew prepares it for launch from the flight deck of the aircraft carrier USS Harry S. Truman on Feb. 22, 2005, while underway in the Persian Gulf.  (Ryan O’Connor/U.S. Navy)