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发表于 2011-2-15 08:02
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来自： 中国江苏南通
回复 blackmclaren
可以所美国的军船，这有什么好喝茶的，那帮人想知道也不知道
goldenwa 发表于 2011-2-10 14:03 
您的美国军船钢板厚度
CVN 21 - 21st Century Carrier
The CVN 21 began as the CVX, a new ship class that is the second and long-term part of the Navy's two-track strategy for aircraft carrier recapitalization. The Navy's vision for CVX is to develop a new class of aircraft carriers to significantly reduce total ownership cost and incorporate an architecture for change and flexibility, while maintaining the core capabilities of Naval aviation (high-volume firepower, survivability, sustainability and mobility) for the 21st Century and beyond. Achieving this vision will require significant design changes to incorporate advances in technology and to focus the design on enhanced affordability since little carrier research and development has been undertaken since the 1960's.
The Department of Defense and the Navy stated on 19 December 2002 that they had decided to rename the CVNX program CVN-21 and that the first ship would have 80 percent of the kinds of new capability that was anticipated by the time the Navy would have reached the CVNX-2. This includes crew reductions, new flight decks, and a new nuclear reactor power plant, which will provide upwards of three times the electrical output of the current power plant. This would open up the opportunity to begin experimenting with the kinds of weapons systems that heretofore were not possible with the kind of electrical power available.
The design of CVN-21 is different than CVNX-1 in that there were changes in the deck spacing and arrangement which was to be a part of CVNX-2. Interior spaces are to be redesigned. Changes as a result of the power plant and some other improvements in the internal spacing with in the ship will result in a reduction in manpower levels. Crew reductions are expected to be roughly eight hundred fewer people -- other than the air wing. Based on these design changes the Navy and the DoD consider CVN-21 to be transformational.
According to studies conducted by the Newport News Shipbuilding Carrier Innovation Center, one possibility evaluated would have been to remove elevator number one (on the starboard side, near the bow catapults) and simply make it part of the flight deck. Elevators two and three would be widened and strengthened to handle up to three aircraft. This would vastly improve aircraft operating efficiency. According to Rear Admiral Alfred G. Harms, Commander, Carrier Group Three, the number one elevator is…"rarely used. Particularly at night because of the safety considerations." This improved flight deck layout would increase air operations safety as well as the ship’s sortie rate.
There's also been a recognition that electromagnetic rail guns were not ready for deployment with a ship in FY '07. They were still in the state of being developed so that they are not as test articles but as deployable systems. And so the notion that the Navy would back-fit into this first hole or into its next iteration those capabilities as they come on line is very much a part of current thinking, and it has to do with the interior space that is freed up and volume in a ship that otherwise wouldn't have been available.
Starting in the mid-1990s, the Navy focused on the development of high-strength low-alloy steel (HSLA-65, -80, and -100) for ship construction in the thickness range of 5/16-inch. to 1-5/8 inch. HSLA-65 and HSLA-100 steels are being considered for immediate application as the primary structure in the DD (X), CVN 77, and CVNX 1 for weight reduction and fabrication cost savings. More recently, Division metallurgists have collaborated with researchers from Japan in a cooperative program to develop structurally acceptable methods to use “under-matched” strength weldments for use with high-strength steel alloys (yield strength greater than 150 ksi). This technology has the potential to significantly reduce the costs of high-strength steel in ship construction.
The Navy believe that the new carriers can shed a few pounds if this steel is used in the carrier hulls. Preliminary calculations indicated that if it was used in hull plate, it could provide equal or greater service life than the traditional high-strength steel, but be thinner, and therefore weigh less. The same would be true for the hull's interior supporting structures. HSLA-65 is stronger and tougher than conventional steel, and has proven itself in commercial bridges, pipelines and other ship above-deck structures. Rigorous certification testing of this new steel is underway.
By early 2003 the CVNX (aircraft carrier, nuclear, experimental) program had been restructured to place as much technology as possible on the lead ship, now called the CVN-21. New propulsion plant, electric catapult, reduced manning, improved survivability and more efficient flight operations are the keys to this new carrier, planned to be available in the 2011 period. CVN 77, which will replace USS Kitty Hawk (CV 63) in 2008, began construction in 2001. CVNX 1, which will replace USS Enterprise (CVN 65) in 2013, was initially scheduled to begin construction in 2006. In fiscal year 1998, CVN 77 initiated the design process necessary to accomplish the technological changes planned for CVNX. The ultimate result of these design efforts will be a carrier class that has not only substantially lower life cycle costs, but also a significantly improved warfighting capability to successfully accomplish a wide range of future missions in what is rapidly becoming an increasingly uncertain world.
On 10 July 2003 it was announced that the U.S. Navy had awarded Northrop Grumman Corporation a contract to support the future aircraft carrier program, CVN 21. Northrop Grumman's Newport News sector is the prime contractor for the award.
The $107.6 million contract allows the company to continue pre-system development and design efforts for CVN 21. Work performed under the contract includes research and design development efforts as well as pre-system development and design in support of ship construction with delivery planned for 2014. This contract is a modification to a previous contract, bringing the total value of the contract to $303.5 million.
According to the DOT&E, the technical risk for this program is moderate. The Navy is conducting a comprehensive early operational assessment in FY04 intended to identify additional risk factors in ten major areas of the ship. By using the proven Nimitz hull form the Navy reduced technical risk in Phase I of the ships development. The Navy plans to use Multi-Function Radar and Volume Search Radar for CVN-21 and these are being developed as part of the new DD(X) destroyer program. The greatest risk will probably be in the IWS, most of which is in Phase II of the CVN 21 program. Safe and adequate operational testing of the IWS providing self-defense against anti-ship cruise missiles will require testing with a selfdefense test ship.
The program has a competitive test and evaluation program set up for EMALS. A successful EMALS program should significantly reduce the complexity, space, and manpower consumed by legacy steam and hydraulic systems. It could also help increase the life expectancy of carrier aircraft due to a much smoother launch sequence.
The LFT&E program, as planned by the Navy and DOT&E, will be a comprehensive evaluation based on CVN survivability studies, battle damage lessons learned, flight deck accident lessons learned, relevant weapons effects tests, probability of kill versus probability of hit studies, damage scenario-based engineering analyses of specific hits, vulnerability assessment reports, a total ship survivability trial, a ship shock trial, and extensive surrogate testing. The CVN 21 program is designing the aircraft carrier for the 21st Century, as the replacement for the NIMITZ Class nuclear aircraft carriers. CVN 21 will be the centerpiece of tomorrow’s Carrier Strike Groups and a contribution to every capability pillar envisioned in Sea Power 21. CVN 21 will be a primary force in Sea Strike with enhancements such as a future air wing that will include the Joint Strike Fighter and Joint Unmanned Combat Air Systems.
CVN 21’s transformational command centers will combine the power of FORCEnet and flexible open system architecture to support multiple simultaneous missions, including integrated strike planning, joint/coalition operations and Special Warfare missions. The CVN 21 based strike group will play a major role in Sea Shield protecting United States interests, while deterring enemies and reassuring allies. CVN 21 will provide the United States the capability to quickly project combat power anywhere in the world, independent of land based support.
Overall, CVN 21 will increase sortie generation rate by 20 percent, increase survivability to better handle future threats and have depot maintenance requirements that could support an increase of up to 25 percent in operational availability. The new design nuclear propulsion plant and improved electric plant together provide three times the electrical generation capacity of a NIMITZ Class carrier. This capacity allows the introduction of new systems such as Electromagnetic Aircraft Launching System, Advanced Arresting Gear, and a new integrated warfare system that will leverage advances in open systems architecture to be affordably upgraded. Other features include an enhanced flight deck, improved weapons handling and aircraft servicing efficiency, and a flexible island arrangement allowing for future technology insertion.
On 21 May 2004, it was announced that the Navy and Northrop Grumman Newport News (NGNN) had successfully negotiated the construction preparation (CP) contract for CVN 21 with advance procurement and advance construction of components and associated design efforts in support of the anticipated FY07 ship procurement for CVN 21 being provided for under the contract. The CVN 21 CP contract was a three-year, cost type contract valued at $1.4 billion, which included a fee earnable to $161.9 million, for advanced procurement of material, design and engineering, and advance construction of CVN 21. This contract included cost, schedule and performance incentives designed to ensure CVN 21 requirements were met at an affordable price. The contract structure had a portfolio of incentives aimed at obtaining the most innovative ship design that would meet the program’s performance goals, while emphasizing timely delivery and control of all costs: material, labor, facilities, overhead and construction.
In August 2004 DoD began describing the CVN 21 program as a 3-ship program encompassing CVN 21 and two similar follow-on ships (CVN 79 and CVN 80) to be procured in later years. |
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