EMALS is an
acronym for
Electromagnetic
Aircraft
Launch
System. It refers to a set of subsystems, still under development at the time of this writeup, which are intended for first use in the future U.S.
aircraft carrier Gerald Ford (
CVN 78). One of the most important systems on a modern supercarrier is that of the
catapult, used to accelerate heavy
aircraft to flying speed and launch them off the carrier. At present, modern carriers use a
steam-pressurized system. For U.S. carriers especially, this is simplified by the fact that high-pressure steam is easily obtained from their
nuclear reactor power plants. Other countries are watching closely, as modern small carriers no longer use high-pressure
boilers, and their
CODAG plants cannot produce steam in the quantities required to operate steam cats.
The problem with steam is that it requires an awful lot of heavy-duty piping running all over the ship, and is very difficult to fine control. In addition, the steam catapult is very sensitive to leaks or damage. EMALS was proposed as a solution. Essentially, EMALS is a linear motor (sort of like a mass driver or railgun) which uses large amounts of electricity to move a catapult head (and, hence, airplanes). The system currently being built for the Ford is capable of putting out 60 megajoules, or roughly thirty sticks of dynamite, with every shot. The energy used is stored in motor generators until needed. With feedback gained during the shots, firing can be controlled much more precisely than that of a steam system, resulting in less wear and tear on the catapult and the aircraft it is accelerating.
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