Friday, March 23, 2007

CVN-21 The US Navy's future aircraft carrier









Compare 13% to 20% reductions in manpower in the first ship to 30 to 40 % reductions in manpower in the second ship. Compare total ownership cost reductions of 8 to 18 % in the first ship to 20 to 50 % reductions in the second ship.








The CVN-21; a catalyst for change.



Essentially, CVN-21 carriers are expected to generate savings in two major ways. One is through an array of design and automation changes to various areas of the ship that reduce the required number of sailors aboard. The other is through reduction in the number of major maintenance overhauls required. NAVSEA expects these changes to save $5 billion per ship over the ships' projected 50-year lifetime. Meanwhile, measures are being taken aimed at improving the carriers' effectiveness and survivability electromagnetic aircraft launching system (EMALS) will replace the steam-powered system used on current ships. The current steam catapults are large, heavy, and operate without feedback control. They impart large loads to the airframe via sudden shock, and are difficult and time consuming to maintain. Additionally, the trend towards heavier, faster aircraft will soon result in energy requirements that exceed the capacity of steam catapults.
EMALS offers a 30% increase in launch energy potential, as well as substantial improvements via reduced weight, smaller volume, and more flexibility; plus increased controllability, availability, reliability, and efficiency. Self-diagnostics can be embedded in it, simplifying maintenance. The other thing that simplifies maintenance is the removal of the 614 kg of steam required for each aircraft launch, plus hydraulics and oils, water for braking, and associated pumps, motors, and control systems. Because an EMALS-based system will take up far less space, it also provides design flexibility. EMALS launchers can be moved far more easily, downsized and incorporated into a ramp to provide additional launchers for short take-off aircraft, etc.
Finally, its steadier acceleration reduces launch strains on naval aircraft, which helps extend their airframe life. That isn't calculated as part of cost savings for the ship, but it definitely adds up over time.
Rear Adm. Dwyer has estimated that these changes will enable the size of the CVN-21 ships' crews to be reduced from about 3,000 to 2,500 and possibly as low as 2,100. Note that some 2,500 personnel are also carried in the air wing, and will not be subject to reductions from any of the methods described here.



These are some new technologies being introduced into the last Nimitz carrier.

A new automated JP-5 jet fuel system with programmable consoles and an improved filtration system (for significant reduction in operational/maintenance workload)


A new vacuum collection sewage system that utilizes fresh water instead of sea water for flushing. This creates fewer long term corrosion problems, and reduces the quantity of sewage from water closets and urinals by ratio of 10 to 1.


Enhanced radio center automation, which involves integrating communications apertures and C4I systems within the radio room to enable an automated full service integrated network that operates at greater effectiveness and efficiency.


A composite mast made from a lighter, composite material instead of steel that reduces topside weight (up to 20 tons) and reduces electromagnetic blockages. It also includes accelerated introduction of new antenna technology: mast clamp current probe antennas will eliminate numerous HF antennas.

Some propulsion plant changes to reduce manpower and maintenance requirements, though this will not represent a full conversion to the new CVN-21 nuclear power plant.


http://www.defenseindustrydaily.com/2005/11/design-preparations-continue-for-the-usas-new-cvn21-supercarrier-updated/index.php


The beauty of this next generation carrier is its progressive design. Each new carrier is suppose to incorporate new cost saving technologies ; If it be reduction in crew size or a more efficient carrier design. You can see this progression in the two CVN-21 carrier charts above. I personally wonder what new improvements we will see in the third carrier. Another great thing that might be possible is unmanned vehicles that can drive up and load munitions onto airplanes. This would provide two benefits. One benefit would be a reduction in personnel, another would be reduction of people on the carrier deck moving around. This would help increase sortie rate. With the coming of unmanned air combat vehicles there will also be a reduction in combat wing personnel. The possibilites of future carrier designs are unlimited.

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