Gerald R. Ford class (or Ford class; previously known as CVN-21 class) is a class of aircraft carrier being built to replace the USS Enterprise (CVN-65) and eventually the United States Navy's existing Nimitz-class carriers, beginning with the delivery of USS Gerald R. Ford (CVN-78). The new vessels have a hull similar to the Nimitz carriers, but introduce technologies since developed such as the Electromagnetic Aircraft Launch System, as well as other design features intended to improve efficiency and reduce operating costs, including sailing with smaller crews.
Video Gerald R. Ford-class aircraft carrier
Design features
Carriers of the Gerald R. Ford class will have:
- Advanced arresting gear.
- Automation, allowing a crew of several hundred fewer than the Nimitz-class carrier.
- The updated RIM-162 Evolved Sea Sparrow missile.
- An AN/SPY-3 X Band multifunction radar and an AN/SPY-4 S Band volume search radar. Designated together as Dual Band Radar (DBR), initially developed for the Zumwalt-class destroyers.
- An Electromagnetic Aircraft Launch System (EMALS) in place of traditional steam catapults for launching aircraft.
- A new nuclear reactor design (the A1B reactor) for greater power generation.
- Stealth features to reduce radar cross-section.
- The ability to carry up to 90 aircraft, including the Boeing F/A-18E/F Super Hornet, Boeing EA-18G Growler, Grumman C-2 Greyhound, Northrop Grumman E-2 Hawkeye, Lockheed Martin F-35C Lightning II, Sikorsky SH-60 Seahawk helicopters, and unmanned combat aerial vehicles such as the Northrop Grumman X-47B.
The US Navy aims to use modern equipment and extensive automation to reduce the crew size and the total cost of future aircraft carriers. The biggest visible difference from earlier supercarriers will be the more aft location of the island (superstructure). Ships of the Gerald R. Ford class are intended to sustain 160 sorties per day for 30-plus days, with a surge capability of 270 sorties per day. Director of Operational Testing Michael Gilmore has criticized the assumptions used in these forecasts as unrealistic and has indicated sortie rates similar to the 120/240 per day of the Nimitz class would be acceptable.
Maps Gerald R. Ford-class aircraft carrier
Development
The current Nimitz-class aircraft carriers in US naval service have been part of United States power projection strategy since Nimitz was commissioned in 1975. Displacing about 100,000 tons when fully loaded, a Nimitz-class carrier can steam faster than 30 knots, cruise without resupply for 90 days, and launch aircraft to strike targets hundreds of miles away. The endurance of this class is exemplified by USS Theodore Roosevelt, which spent 159 days underway in support of Operation Enduring Freedom without visiting a port or being refueled.
The Nimitz design has accommodated many new technologies over the decades, but it has limited ability to support the most recent technical advances. As a 2005 Rand report said, "The biggest problems facing the Nimitz class are the limited electrical power generation capability and the upgrade-driven increase in ship weight and erosion of the center-of-gravity margin needed to maintain ship stability."
With these constraints in mind, the US Navy developed what was initially known as the CVN-21 program, which ultimately evolved into CVN-78, Gerald R. Ford. Improvements were made through developing technologies and more efficient design. Major design changes include a larger flight deck, improvements in weapons and material handling, a new propulsion plant design that requires fewer people to operate and maintain, and a new, smaller island that has been pushed aft. Technological advances in electromagnetics have led to the development of an Electromagnetic Aircraft Launch System (EMALS) and an Advanced Arresting Gear (AAG). An integrated warfare system, the Ship Self-Defense System (SSDS), has been developed to allow the ship to more easily take on new missions. The new Dual Band Radar (DBR) combines S-band and X-band radar. Flight deck changes support the requirements for a higher sortie rate, around 160 a day with surges to 270.
These advances will allow the new Gerald R. Ford-class carriers to launch 25% more sorties, generate triple the electrical power with improved efficiency, and offer crew quality-of-life improvements.
Flight deck
Changes to the flight deck are the most visible differences between the Nimitz and Gerald R. Ford classes. Several sections have been altered to improve aircraft handling, storage, and flow, all in the service of increasing the sortie rate.
Catapult No. 4 on the Nimitz class cannot launch fully loaded aircraft because of a deficiency of wing clearance along the edge of the flight deck. CVN-78 will have no catapult-specific restrictions on launching aircraft, but still retains four catapults, two bow and two waist. The number of aircraft lifts from hangar deck to flight deck level was reduced from four to three.
Another major change is that the smaller, redesigned island will be further aft than those of older carriers. This shift creates deck space for a centralized rearming and refueling location, and thereby reduces the number of times that an aircraft will have to be moved after landing before it can be relaunched. Fewer aircraft movements require, in turn, fewer deck hands to accomplish them, reducing the size of the ship's crew and increasing sortie rate.
As well, the movement of weapons from storage and assembly to the aircraft on the flight deck has been streamlined and accelerated. Ordnance will be moved to the centralized rearming location via relocated, higher-capacity weapons elevators that use linear motors. The new path that ordnance follows does not cross any areas of aircraft movement, thereby reducing traffic problems in the hangars and on the flight deck. According to Rear Admiral Dennis M. Dwyer, these changes will make it hypothetically possible to rearm the airplanes in "minutes instead of hours".
Power generation
The new Bechtel A1B reactor for the Gerald R. Ford-class is smaller and simpler, requires fewer crew, and yet is far more powerful than the Nimitz-class A4W reactor. Two reactors will be installed on each Gerald R. Ford-class carrier, providing almost 700 MW which is 25% greater than 550 MW of the two A4W. As the Gerald R. Ford-class is primarily an electric boat; electrical capacity of the reactors was increased by 2.5 times over that of the Nimitz-class.
The propulsion and power plant of the Nimitz-class carriers was designed in the 1960s, when onboard technologies did not require the same quantity of electrical power that modern technologies do. "New technologies added to the Nimitz-class ships have generated increased demands for electricity; the current base load leaves little margin to meet expanding demands for power."
Compared to the Nimitz-class reactor, the ''Gerald R. Ford-class reactor has about half as many valves, piping, major pumps, condensers, and generators. The steam-generating system uses fewer than 200 valves and only eight pipe sizes. These improvements lead to simpler construction, reduced maintenance, and lower manpower requirements as well as to a more compact system that requires less space in the ship. The modernization of the plant led to a higher core energy density, lower demands for pumping power, a simpler construction, and the use of modern electronic controls and displays. The new plant requires just one-third the watchstanding requirements and a decrease of required maintenance.
A larger power output is a major component to the integrated warfare system. Engineers took extra steps to ensure that integrating unforeseen technological advances onto a Gerald R. Ford-class aircraft carrier would be possible. The Navy expects the Gerald R. Ford class will be part of the fleet for 90 years, until the year 2105, which means that the class must successfully accept new technology over the decades.
Electromagnetic Aircraft Launch System
The Nimitz-class aircraft carriers used steam-powered catapults to launch aircraft. The Electromagnetic Aircraft Launch System (EMALS) installed on the Gerald R. Ford-class aircraft carrier is more efficient, smaller, lighter, more powerful, and easier to control. Increased control means that EMALS will be able to launch heavier and lighter aircraft than the steam catapult. Also, the use of a controlled force will reduce the stress on airframes, resulting in less maintenance and a longer lifetime for the aircraft. (EMALS will not be retrofitted onto the Nimitz class, which cannot generate enough electricity to power it.)
Advanced Arresting Gear landing system
Electromagnets are also being used in the new Advanced Arresting Gear (AAG) system. The current system relies on hydraulics to slow and stop a landing aircraft. While the hydraulic system is effective, as demonstrated by more than fifty years of implementation, the AAG system offers a number of improvements. The current system is unable to capture UAVs without damaging them due to extreme stresses on the airframe. UAVs do not have the necessary mass to drive the large hydraulic piston used to trap heavier, manned airplanes. By using electromagnetics the energy absorption is controlled by a turbo-electric engine. This makes the trap smoother and reduces shock on airframes. Even though the system will look the same from the flight deck as its predecessor, it will be more flexible, safe, and reliable, and will require less maintenance and manning.
Sensors and self-defense systems
Another addition to the Gerald R. Ford class is an integrated active electronically scanned array search and tracking radar system. The dual-band radar (DBR) was being developed for both the Zumwalt-class guided missile destroyers and the Gerald R. Ford-class aircraft carriers by Raytheon. The island can be kept smaller by replacing six to ten radar antennas with a single six-faced radar. The DBR works by combining the X band AN/SPY-3 multifunction radar with the S band Volume Search Radar (VSR) emitters, distributed into three phased arrays. The S-band radar was later deleted from the Zumwalt class destroyers as a cost saving measure.
The three faces dedicated to the X-band radar are responsible for low altitude tracking and radar illumination, while the other three faces dedicated to the S-band are responsible for target search and tracking regardless of weather. "Operating simultaneously over two electromagnetic frequency ranges, the DBR marks the first time this functionality has been achieved using two frequencies coordinated by a single resource manager."
This new system has no moving parts, therefore minimizing maintenance and manning requirements for operation. The AN/SPY-3 consists of three active arrays and the Receiver/Exciter (REX) cabinets abovedecks and the Signal and Data Processor (SDP) subsystem below-decks. The VSR has a similar architecture, with the beamforming and narrowband down-conversion functionality occurring in two additional cabinets per array. A central controller (the resource manager) resides in the Data Processor (DP). The DBR is the first radar system that uses a central controller and two active-array radars operating at different frequencies. The DBR gets its power from the Common Array Power System (CAPS), which comprises Power Conversion Units (PCUs) and Power Distribution Units (PDUs). The DBR is cooled via a closed-loop cooling system called the Common Array Cooling System (CACS).
The REX consists of a digital and an analog portion. The digital portion of the REX provides system-level timing and control. The analog portion contains the exciter and the receiver. The exciter is a low-amplitude and phase noise system that uses direct frequency synthesis. The radar's noise characteristics support the high clutter cancellation requirements required in the broad range of maritime operating environments that DBR will likely encounter. The direct frequency synthesis allows a wide range of pulse repetition frequencies, pulse widths, and modulation schemes to be created.
The receiver has high dynamic range to support high clutter levels caused by close returns from range-ambiguous Doppler effect waveforms. The receiver has both narrow band and wideband channels, as well as multichannel capabilities to support monopulse radar processing and side lobe blanking. The receiver generates digital data and sends the data to the signal processors.
The DBR uses IBM commercial off-the-shelf (COTS) supercomputers to provide control and signal processing. DBR is the first radar system to use COTS systems to perform the signal processing. Using COTS systems reduces development costs and increases system reliability and maintainability. The high-performance COTS servers perform signal analysis using radar and digital signal processing techniques, including channel equalization, clutter filtering, Doppler processing, impulse editing, and implementation of a variety of advanced electronic protect algorithms. The IBM supercomputers are installed in cabinets that provide shock and vibration isolation. The DP contains the resource manager, the tracker, and the command and control processor, which processes commands from the combat system.
The DBR utilizes a multi-tier, dual-band tracker, which consists of a local X band tracker, a local S band tracker, and a central tracker. The central tracker merges the local tracker data together and directs the individual-band-trackers' updates. The X band tracker is optimized for low latency to support its mission of providing defense against fast, low-flying missiles, while the VSR tracker is optimized for throughput due to the large-volume search area coverage requirements.
The combat system develops doctrine-based response recommendations based on the current tactical situation and sends the recommendations to the DBR. The combat system also has control of which modes the radar will perform. Unlike previous-generation radars, the DBR does not require an operator and has no manned display consoles. The system uses information about the current environment and doctrine from the combat system to make automated decisions, not only reducing reaction times, but also reducing the risks associated with human error. The only human interaction is for maintenance and repair activities.
The Enterprise Air Surveillance Radar (EASR) is a new design surveillance radar that is to be installed in the second Gerald R. Ford-class aircraft carrier, USS John F. Kennedy (CVN-79), in lieu of the Dual Band radar. The America-class amphibious assault ships starting with LHA-8 and the planned LX(R) will also have this radar. The EASR suite's initial per-unit cost will be about $180 million less than the DBR, for which the estimate is about $500 million.
The carrier will be armed with the Raytheon Evolved Sea Sparrow missile (ESSM), which defends against high-speed, highly maneuverable anti-ship missiles. The close-in weapon system, and the rolling airframe missile (RAM) from Raytheon and Ramsys GmbH are also on board.
Possible upgrades
Each new technology and design feature integrated into the Gerald R. Ford-class aircraft carrier improves sortie generation, manning requirements, and operational capabilities. New defense systems, such as free-electron laser directed-energy weapons, dynamic armor, and tracking systems will require more power. "Only half of the electrical power-generation capability on CVN-78 is needed to run currently planned systems, including EMALS. CVN-78 will thus have the power reserves that the Nimitz class lacks to run lasers and dynamic armor." The addition of new technologies, power systems, design layout, and better control systems results in an increased sortie rate of 25% over the Nimitz-class and a 25% reduction in manpower required to operate.
Breakthrough waste management technology will be deployed on Gerald R. Ford. Co-developed with the Carderock Division of the Naval Surface Warfare Center, PyroGenesis Canada Inc., was in 2008 awarded the contract to outfit the ship with a Plasma Arc Waste Destruction System (PAWDS). This compact system will treat all combustible solid waste generated on board the ship. After having completed factory acceptance testing in Montreal, the system was scheduled to be shipped to the Huntington Ingalls shipyard in late 2011 for installation on the carrier.
The Navy is actively developing a weapon system called the free-electron laser (FEL) to address the cruise missile threat and the swarm-boat threat against Gerald R. Ford-class carriers. An FEL uses an electron gun to generate a stream of electrons. The electrons are then sent into a linear particle accelerator to boost them to near light speeds. The accelerated electrons are then sent into a device, known informally as a wiggler, that exposes the electrons to a transverse magnetic field, which causes the electrons to "wiggle" from side to side and release some of their energy in the form of light (photons). The photons are then bounced between mirrors and emitted as a coherent beam of laser light. To increase the efficiency of the system some electrons are then recycled to the front of the particle accelerator via an energy recovery loop. The cost to fire one shot from an FEL is about $1 and draws about 10 MW of electrical power.
3D computer-aided design
Newport News Shipbuilding used a full-scale three-dimensional product model developed in Dassault Systèmes CATIA V5 to design and plan the construction of the Gerald R. Ford class of aircraft carriers. This enables engineers and designers to test visual integration in design, engineering, planning and construction of components and subsystems. CVN-78 is the first aircraft carrier to be designed in a full-scale 3D product model. This modeling enabled the rooms within the ship to be modular, so that future upgrades can be implemented by designers simply by swapping a box in and locking it down.
This method of designing workflow also resulted in improvements to weapon handling procedures and an increase in potential sorties-per-day. Weapons-handling paths on Nimitz-class ships were designed for the potential nuclear missions of the Cold War. The current flow of weapons from storage areas in the interior of the Nimitz-class ship to loading on aircraft involves several horizontal and vertical movements to various staging and build-up locations within the ship. These movements around the ship are time-consuming and manpower-intensive and typically involve sailors manually moving weapons loaded on carts. Also, the current locations of some of the Nimitz-class weapons elevators conflict with the flow of aircraft on the flight deck, slowing down the generation of sorties or making some elevators unusable during flight operations.
The CVN 21 class was designed to have better weapons movement paths, largely eliminating horizontal movements within the ship. Current plans call for advanced weapons elevators to move from storage areas to dedicated weapons-handling areas. Sailors would use motorized carts to move the weapons from storage to the elevators at different levels of the weapons magazines. Linear motors are being considered for the advanced weapons elevators. The elevators will also be relocated such that they will not impede aircraft operations on the flight deck. The redesign of the weapons movement paths and the location of the weapons elevators on the flight deck will reduce manpower and contribute to a much higher sortie generation rate.
Planned aircraft complement
The Gerald R. Ford class is designed to accommodate the new Joint Strike Fighter carrier variant aircraft (F-35C), but aircraft development and testing delays have affected integration activities on CVN-78. These integration activities include testing the F-35C with CVN-78's EMALS and advanced arresting gear system and testing the ship's storage capabilities for the F-35C's lithium-ion batteries (which provide start-up and back-up power), tires, and wheels. As a result of F-35C developmental delays, the US Navy will not field the aircraft until at least 2018--one year after CVN-78 delivery. As a result, the Navy has deferred critical F-35C integration activities, which introduces risk of system incompatibilities and costly retrofits to the ship after it is delivered to the Navy.
Crew accommodations
Systems that reduce crew workload have allowed the ship's company on Gerald R. Ford-class carriers to total only 2,600 sailors, about 600 fewer than a Nimitz-class carrier. The massive, 180-man berthing areas on the Nimitz class are replaced by 40-rack berthing areas on Gerald R. Ford-class carriers. The smaller berthings are quieter and the layout requires less foot traffic through other spaces. The racks are typically stacked three high, with one locker per person and extra lockers for those without storage space under their rack. The berthings do not feature modern "sit-up" racks with more headroom (each rack can only accommodate a sailor lying down). Each berthing has an associated head, including showers, vacuum-powered septic-system toilets (no urinals since the berthings are built gender-neutral) and sinks to reduce travel and traffic to access those facilities. Wifi-enabled lounges are located across the passageway in separate spaces from the berthing's racks.
Medical facilities
Gerald R. Ford, first in the class, has an on-board hospital that includes a full lab, pharmacy, operating room, 3-bed intensive care unit, 2-bed emergency room, and 41-bed hospital ward, staffed by 11 medical officers and 30 hospital corpsmen.
Construction
Construction began on 11 August 2005, when Northrop Grumman held a ceremonial steel cut for a 15-ton plate that will form part of a side shell unit of the carrier. Construction began on components of CVN-78 in early 2007 and is nearing completion. It is under the final steps of construction at Newport News Shipbuilding, a division of Huntington Ingalls Industries (formerly Northrop Grumman Shipbuilding) in Newport News, Virginia. This is the only shipyard in the United States capable of building nuclear-powered aircraft carriers.
In 2005, it was estimated to cost at least $8 billion excluding the $5 billion spent on research and development (though that was not expected to be representative of the cost of future members of the class). A 2009 report said that Gerald R. Ford would cost $14 billion including research and development, and the actual cost of the carrier itself would be $9 billion. The life-cycle cost per operating day of a carrier strike group (including aircraft) was estimated at $6.5 million in 2013 published by the Center for New American Security.
Originally, a total of three carriers have been authorized for construction, but if the Nimitz-class carriers and Enterprise were to be replaced on a one-for-one basis, eleven carriers would be required over the life of the program. However, the last Nimitz-class aircraft carrier is not scheduled to be decommissioned until 2058.
In a speech on 6 April 2009, then Secretary of Defense Robert Gates announced that the program would shift to a five-year building program so as to place it on a "more fiscally sustainable path". Such a measure would result in ten carriers after 2040. That changed by 2016, when former Secretary of the Navy Ray Mabus recommended a 355-ship fleet, with 12 aircraft carriers, in the December 2016 Force Structure assessment (FSA). If enacted, this policy would necessitate an increase to a three to four-year building program.
First-of-class type design changes
As construction of CVN-78 progresses, the shipbuilder is discovering first-of-class type design changes, which it will use to update the model before the follow-on ship construction. To date, several of these design changes have related to EMALS configuration changes, which have required electrical, wiring, and other changes within the ship. Although the Navy reports that these EMALS-related changes are nearing completion, it anticipates additional design changes stemming from remaining advanced arresting gear development and testing. In total, over 1,200 anticipated design changes remain to be completed (out of nearly 19,000 planned changes). According to the Navy, many of these 19,000 changes were programmed into the construction schedule early on--a result of the government's decision at contract award to introduce improvements during construction to the ship's warfare systems, which are heavily dependent on evolving commercial technologies.
Naming
There was a movement by the USS America Carrier Veterans' Association to have CVN-78 named after America rather than after President Ford. Eventually, the amphibious assault ship LHA-6 was named America.
On 27 May 2011, the U.S. Department of Defense announced the name of CVN-79 would be USS John F. Kennedy.
On 1 December 2012, Secretary of the Navy Ray Mabus announced that CVN-80 would be named USS Enterprise. The information was delivered during a prerecorded speech as part of the deactivation ceremony for the previous USS Enterprise (CVN-65). The future Enterprise (CVN-80) will be the ninth U.S. Navy ship to bear this name.
Ships in class
There are expected to be ten ships of this class. To date, five have been announced:
See also
Notes
References
External links
- Aircraft Carriers - CVN - US Navy Fact File
- Building The Ford Class Aircraft Carriers - Newport News Shipbuilding
- Design & Preparations Continue for the USA's New CVN-21 Super-Carrier (updated), Defense Industry Daily. Provides an extensive briefing re: the new ship class, and adds entries for many of the contracts under this program.
- Gerald R. Ford Class (CVN-78) Aircraft Carrier on Navy Recognition site
- GAO Reports: Poor Outcomes Are the Predictable Consequences of the Prevalent Acquisition Culture (October 2015), Follow-On Ships Need More Frequent and Accurate Cost Estimates to Avoid Pitfalls of Lead Ship (June 2017)
Source of the article : Wikipedia