US Navy testing electromagnetic catapult on aircraft carrier
For almost as long as aircraft carriers have existed, they've been equipped with steam-powered catapults to help fighters and bombers get airborne. That's a remarkably old-fashioned technology when you're launching stealth fighters that cost upwards of $20 million each. Aircraft carriers are gigantic, but the runways simply aren't long enough for most planes to generate sufficient lift under their own power.
The US Navy is now testing a replacement system called the Electromagnetic Aircraft Launch System (EMALS) aboard the new USS Gerald R. Ford. It works by using an electric current to generate magnetic fields that propel a carriage down the track built into the runway, launching planes much more smoothly and efficiently than the old steam catapults with improved reliability. A steam catapult takes up a great deal of space and weigh in excess of 1,300 pounds. These systems take a long time to recharge after each launch, and the launch itself is rather abrupt. There's no smooth acceleration with a steam piston, resulting in increase wear on the body of the aircraft. Steam catapults also use more power than the EMALS system.
The US Navy is now testing a replacement system called the Electromagnetic Aircraft Launch System (EMALS) aboard the new USS Gerald R. Ford. It works by using an electric current to generate magnetic fields that propel a carriage down the track built into the runway, launching planes much more smoothly and efficiently than the old steam catapults with improved reliability. A steam catapult takes up a great deal of space and weigh in excess of 1,300 pounds. These systems take a long time to recharge after each launch, and the launch itself is rather abrupt. There's no smooth acceleration with a steam piston, resulting in increase wear on the body of the aircraft. Steam catapults also use more power than the EMALS system.
Article:
http://www.edn.com/design/analog/4341471/Electronics-poised-to-replace-steam-powered-aircraft-launch-system