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An EMALS catapult test range in the United States |
It could still be a long while before Chinese engineers master a technology that the US has been working on since the mid-1980s
Chinese engineers are reportedly trying to develop an electromagnetic catapult system for China's future aircraft carriers, the
People's Liberation Army Daily claimed in a 28 April report.
General Ma Weiming (馬偉明), a professor at the PLA Naval University of Engineering, is said to have led the efforts to develop the system, which seeks to emulate the development of the Electromagnetic Aircraft Launch System (EMALS) in the United States.
Compared to existing steam catapult technology, an electromagnetic catapult is seen to offer improved efficiency, increased launch energy, lower through-life costs and improved end-speed control. Additionally, the scalability of the system is better suited for launching unmanned aerial vehicles.
My article, published today in
Jane's Defence Weekly, continues
here (subscription required). What follows is background information not included in my
JDW article:
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General Ma Weiming |
Aside from older carriers, like China’s refurbished ex-
Varyag, which use ski jumps to launch aircraft, modern nuclear aircraft carriers use steam catapult technology to give naval aircraft the extra boost necessary to launch (push) from their decks. However, steam technology — which usually uses a piping system to collect steam from the ship’s nuclear reactor (heat is transmitted to a secondary loop via a heat exchanger)* — is very stressful on airframes and is maintenance intensive.
EMALS catapults use a process similar to an electromagnetic rail gun to accelerate (pull) the shuttle that propels an aircraft on the deck, and allows for more gradual acceleration which reduces stress on the airframe. Given the amount of energy required to propel an aircraft from a deck within 3 seconds — enough to power 12,000 homes, according to
Defense Industry Daily — carriers using electromagnetic propulsion require generators that can weigh as much as 80,000lbs.
Provided the technology is developed in time, the US Navy’s CVN-21 Gerald R. Ford-class aircraft carriers, which are in the building stage, will use EMALS on their decks. The UK has also mulled the technology for its Queen Elizabeth-class carriers, in part to accommodate F-35C aircraft. The US-based General Atomics is spearheading the efforts. Among the advantages of EMALS catapults are their higher energy, which allow for launching of heavier naval aircraft on a deck. It is also said that EMALS make it easier to control the sequence of UAV launches.
Test launches using EMALS have already been successful with a variety of aircraft, with further compatibility testing scheduled for this year and reliability tests next year. System integration and certification expected in 2015, the same year the first CVN-21 hull, the USS
Gerald R. Ford, is scheduled for commissioning.
China reportedly has plans to build two conventional and two nuclear aircraft carriers by 2020. Unconfirmed reports also indicate that the conventionally powered ex-
Varyag, which is expected to enter service in August, could eventually be retrofitted as a nuclear-powered carrier and outfitted with EMALS catapults.
*With thanks to James Holmes of the US Naval War College for explaining the principle behind this.