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CVN 78 comes with a brand new propulsion plant design. The A1B reactor plant and its associated propulsion plant would require 50% fewer people to operate and maintain than a Nimitz class. The new A1B reactors also have 25% more energy than legacy A4W reactor plants, allowing for more steaming days and increased operational availability for the Combatant Commander over a 50-year service life.

The Gerald Ford-class carriers have more powerful and simpler A1B reactors reported to be 25% more powerful than A4W, hence about 700 MWt, but running a ship which is entirely electrical, including an electromagnetic aircraft launch system or catapault. Accordingly, the ship has 2.5 times the electrical capacity of Nimitz class. Ford-class are designed to be refuelled in mid-operational life of 50 years.

The Bechtel Marine Propulsion Corporation (BMPC) designed the A1B to be smaller, more efficient, and to have three times the electrical power of the A4W reactor. BMPC designed the reactor to have a higher core energy density, which resulted in a decrease of required maintenance, by 2/3 of the A4W reactor.

The christening of the USS Gerald R. Ford (CVN 78) unveiled the new generation of super carrier. She is the first of three planned for the new Ford-class. This all new redesign incorporates the new A1B nuclear reactor, which generates three-times the power of the Nimitz-class A4W. The reactor would power the new Electromagnetic Aircraft Launch System (or EMALS) and would also replace other traditionally-assigned hydraulic with electromagnetic systems, scaling back the amount of crew needed for the ship. The Ford would accommodate up to 90 aircraft and would be among the first wave of navy ships to utilize stealth technology.

One major change is that the reactor plants would deliver a substantially greater electric power generating capacity to support the shift to electromagnetic catapults and arresting gear, and to power future high-energy weapons. Nimitz-class CVNs have 64 MWe electric generating capacity. Ford-class CVNs are expected to have 300 MWe generating capacity. A switch to electrical systems would make possible major reductions in the maintenance and operating crew required. Additionally, electric systems, such as catapults, can be easily programmed to provide optimum mechanical power for any aircraft loads.

For ships as large as aircraft carriers, electric propulsion does not offer operational, cost or weight advantages over steam. In the longer term, electrically driven, ducted propellers or water jets could be attractive since noise-producing cavitation can be significantly reduced.

Distribution of energy in electrical form through a ship is much easier and more reliable than traditional energy forms (steam, hydraulic and pneumatic power). Ability to quickly switch power to priority uses and to redirect power as needed in an emergency enhance ship survivability, provides new peak power options and significantly reduces crew needed for damage control.

The A1B has 50 percent fewer valves, piping, pumps, condensers, and generators, which supports a projected two-third reduction in watch standing requirements and significantly less maintenance.

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Page last modified: 07-02-2016 19:41:16 ZULU