Electromagnetic catapult


An electromagnetic catapult is a type of aircraft catapult that uses a linear induction motor system rather than the single-acting pneumatic cylinder system in conventional steam catapults. The system is typically used on aircraft carriers to launch fixed-wing carrier-based aircraft, employing the principles of electromagnetism and Lorentz force to accelerate and assist their horizontal takeoff from the shorter flight deck runways.
Currently, only the United States and China have successfully developed electromagnetic catapults, which are installed on the Gerald R. Ford-class aircraft carriers, the Type 003 aircraft carrier Fujian and the upcoming Type 076 amphibious assault ship Sichuan.

Advantages

Electromagnetic catapults have several advantages over their older, superheated steam-based counterparts.
  • Electromagnetic catapults are more compact and also weigh less than steam catapults, the latter requiring extensive and sophisticated piping, pump, pressure container, boiler and energy-intensive desalination systems below the flight deck, thus freeing up spaces for the hangar and other equipment system installations.
  • Electromagnetic operation recharges via electric energy and thus much faster than the pressurization process of steam systems, where steam takes time to boil and accumulate.
  • Electromagnetic catapults are configurable and can assign varying power outputs to different sections of the catapult rail, thus allowing them to tailor optimal acceleration to individual aircraft according to different payload weights and takeoff behaviours.
  • Electromagnetic catapult does not suffer power loss with distance, temperature changes and fluid leakages.
  • Electromagnetic acceleration is more uniform, unlike steam acceleration, whose accelerative force is always highest at the very initial phase thus creating a distinct "jolt" at the start. This therefore considerably reduces the impulsive stress upon the airframe, resulting in increased safety and endurance as well as lower maintenance costs for the aircraft.
  • Electromagnetic systems have a more minimalistic construct with fewer linkage components, and thus are expected to cost less to build and require less maintenance.

    History

Developed in the 1950s, steam catapults have a proven history of reliability due to it being a mature technology. Carriers equipped with four steam catapults have been able to use at least one of them at 99.5% of the time. These have, however, several drawbacks. One group of Navy engineers wrote: "The foremost deficiency is that the catapult operates without feedback control. With no feedback, there often occurs large transients in tow forces that can damage or reduce the life of the airframe." The steam system is massive, inefficient, and hard to control. These control problems allow steam-powered catapults to launch heavy aircraft, but not aircraft as light as many unmanned aerial vehicles.
In the United States, General Atomics Electromagnetic Systems developed the world's first operational modern electromagnetic catapult, named Electromagnetic Aircraft Launch System, for the United States Navy. The system was installed on USS Gerald R. Ford and currently fitting-out USS John F. Kennedy, the lead ship and second ship of the new Gerald R. Ford-class supercarriers, replacing the traditional steam catapults on the retiring Nimitz class. The innovations on EMALS eliminate the traditional system requirements to desalinate, boil, convey and store steam, freeing up considerable area below deck. With the EMALS, Gerald R. Ford can accomplish 25% more aircraft launches per day than the Nimitz class and requires 25% fewer crew members. The EMALS uses a linear induction motor, which uses alternating current to generate magnetic fields that propel a carriage along a track to launch the aircraft. A system somewhat similar to EMALS, Westinghouse's electropult, was developed in 1946 but not deployed.
In China, the China Shipbuilding Industry Corporation and the Chinese Academy of Engineering have jointly developed an electromagnetic catapult system in the 2000s for the People's Liberation Army Navy's aircraft carrier programme, but with a different technical approach. The Chinese adopted a medium-voltage, direct current motor-supercapacitor propulsion system, instead of the alternating current motor-flywheel catapult system that United States developed for the Gerard R. Ford class. The system first installed on the aircraft carrier Fujian, and video footages of catapult launch tests of the J-15T, J-35 and KJ-600 aircraft during its seventh sea trial was officially released on September 22, 2025, making the ship the first aircraft carrier in the world confirmed to launch fifth-generation fighters successfully using an electromagnetic catapult system.
The concept of a ground carriage is intended for civilian use and takes the idea of an electromagnetic aircraft launch system one step further, with the entire landing gear remaining on the runway for both takeoff and landing.

Operational systems

China

Rear Admiral Yin Zhuo of the Chinese Navy said in 2013 that China's Type 003 next aircraft carrier would also have an electromagnetic aircraft launch system. Multiple prototypes were spotted by the media in 2012, and aircraft capable of electromagnetic launching were undergoing testing at a Chinese Navy research facility.
According to a report in July 2017, construction of Type 003 was rescheduled in order to choose between a steam or electromagnetic catapult, and the latest competition results showed electromagnetic launchers would be used on Type 003.
China's electromagnetic catapult was installed on its third aircraft carrier Fujian in 2021, becoming the only carrier besides the U.S. Navy's Gerald R. Ford-class to deploy this technology. The electromagnetic catapult is also installed on the upcoming Type 076 amphibious assault ship, enabling the ship to launch unmanned combat aerial vehicles and possibly manned carrier-based aircraft.
Fujian began sea trials in May 2024. By May 2025, she had completed eight sea trials, including takeoff and landing tests with J-15T heavy multirole fighters, J-35 stealth fighters and KJ-600 AEW&C aircraft. In August 2025, Chinese media released a video teasing the launch of the Shenyang J-15T variant on the Fujian with electromagnetic catapults. Though no complete sequence of the take-off and recovery was shown, analysts believed the carrier and its air wing were reaching an important milestone.
On 22 September 2025, the Chinese state broadcaster released multiple videos and photos — suspected to be from a sea trial earlier in the year — showing the complete catapult launch and arrestor recovery sequence for J-15T, J-35 and KJ-600 aircraft on the Fujian. PLA Navy also announced that Fujian had achieved "initial full-deck operational capability", laying the foundation for the subsequent integration with the carrier aviation wing and the carrier battle group. The EMALS of Fujian is powered by a Medium-Voltage Direct Current integrated power system—the first of its kind in the world, which is more reliable compared to the AC-based EMALS of the Gerald R. Ford-class.
The planned Type 004 aircraft carrier, a suspected nuclear-powered supercarrier currently in construction at the Dalian Shipyard since 2024, will almost certainly be also equipped with electromagnetic catapults due to the success of the system on Fujian.

United States

was designed for and into the. A proposal to retrofit it into carriers was rejected. John Schank said: "The biggest problems facing the Nimitz class are the limited electrical power generation capability and the upgrade-driven increase in ship weight and erosion of the center-of-gravity margin needed to maintain ship stability."
On 28 July 2017, Lt. Cmdr. Jamie "Coach" Struck of Air Test and Evaluation Squadron 23 performed the first EMALS catapult launch from USS Gerald R. Ford in an F/A-18F Super Hornet.
By April 2021, 8,000 launch/recovery cycles had been performed with the EMALS and the AAG arrestor system aboard USS Gerald R. Ford. The USN also stated that the great majority of these cycles had occurred in the prior 18 months and that 351 pilots had completed training on the EMALS/AAG.
The Ford was certified for flight deck operations using the EMALS in 2022.

Systems under development

India

In 2013, the Indian Navy reportedly sought to equip the aircraft carrier with electromagnetic catapult, which could enable the launching of larger aircraft as well as unmanned combat aerial vehicles.
As per August 2024 media report, Research & Development Establishment has developed a scaled-down technology demonstrator, known as Electro-Magnetic Launch System capable of launching payloads up to over a short span of. The demonstrator is being further developed into a full-scale EMLS for application on future aircraft carriers. Industry partners were reportedly being sought to develop the full-scale system to launch platforms weighing up to 40 tons can be handled by the system. Two crucial technologies including Pulse Power and Linear Electric Machine were successfully developed.

Russia

Russia's United Shipbuilding Corporation is developing new launch systems for warplanes based on aircraft carriers, USC President Alexei Rakhmanov told TASS on 4 July 2018.

Ships with electromagnetic catapult

United States