One of the most advanced systems for launch an aircraft from a ship is nearing completion, and it's located inland at the Naval Air Engineering Station in Lakehurst, New Jersey. The system is a new electromagnetic aircraft launch system (EMALS) for the U.S. Navy.
EMALS overcomes many drawbacks of the steam catapult systems in service on today's aircraft carriers, which are large, heavy, energy-inefficient, manpower-intensive and require steam production from a carrier's engineering plant. EMALS, which uses magnetic pulses to launch planes, provides better performance, requires less manpower and costs less to maintain than steam catapults. EMALS is capable of launching all conventional and short takeoff fixed-wing carrier aircraft, including the Joint Strike Fighter.
For the EMALS facility, "Our goal will be to stay ahead of the fleet in terms of the number of shots," says Dough Swope, EMALS test-site engineer. "This site will always have more shots than the older ship to catch fatigue issues."
Overall, the Lakehurst base is 7,400 acres; EMALS takes up about 15 acres and is situated next to an old steam catapult built there in the 1950s.
To get a taste for the technology, engineers visited the nearby amusement park Great Adventure to examine the Batman and Robin ride, which also uses electromagnetic propulsion. But as Swope is quick to point out, while the same technology, "It is a different energy level for different loads." Instead of a crowd of screaming teenagers out for an afternoon thrill, EMALS will be capable of accelerating a heavy fighter jet from a standing start to 180 knots in just 307 feet.
Loftus Construction of Cinnamonson was the concrete, excavation and sitework contractor on the project. DMJM was the designer of the project and Hensel Phelps Construction Co. is providing construction management services.
Swope says the project will look and perform similar to the top of an aircraft carrier when complete. Included will be 900 feet of break rail, and anywhere within 100 feet of the launcher will be a simulated aircraft deck. The actual launch motor is 348 feet, and will be mounted in a trough with roughly 3-1/2-foot-thick concrete walls.
Because of a high water table, Loftus had to sheetpile the entire area. Environmental sensitivities, such as a dewatering limit, mandated multiple pours. Surrounding the steel-plated trough top will be 175 feet of landing load-rating runway.
To help manage the project, Hensel Phelps used Vela Systems' mobile field management software. According to the company, by replacing field notebooks with Vela software and Tablet PCs, its customers save four to eight hours per week per user, accelerate project delivery by two days per month, capture the true cost of quality, and reduce litigation risk through standardized documentation.
The software enables people in the field to mark up drawings, make notations and initiate work processes while on the job site in their own handwriting. With the VelaViewer, field personnel can mark up plans on the screen and insert pushpins to pinpoint issues that need to be addressed. Vela Systems software streamlines and accelerates all field processes in construction and capital projects.
"With Vela Systems, our superintendent could mark the exact location of a work item or issue on a structural drawing with a pushpin and add text, a photograph and audio," said Jeff Brown, project manager for Hensel Phelps. "Timely, concise information could be readily transferred from the field to the owner, the architect and subcontractors in a manner that could be clearly understood so issues could be quickly resolved.
"Vela enabled our staff to cut the amount of time it takes to bring an issue to the attention of the responsible parties and get it turned around," Brown continued. "The superintendent liked how Vela allowed him to prepare punch lists, work lists and to-do lists without typing. It improved his productivity and increased accuracy by eliminating redundant data input."
Adds Josh Cantor, Velas Systems co-founder, Hensel Phelps communicated faster and more accurately because information flowed more rapidly and accurately from the field to subcontractors, executives and design engineers. It also saved time and increased productivity, as the Hensel Phelps team no longer needed to spend eight to 12 hours per week transcribing information from paper field documents into computers, and could instead focus on resolving problems and moving the project forward. Vela also reduced risk, as the software created documentation that can be used to answer questions and, thanks to improved communications, reduced the risk of misunderstandings and error.
According to the Navy, EMALS is a complete launch system designed to replace the existing steam catapult on CVN-78, the first ship of the CVN-21 Future Aircraft Carrier Class.
The basic design consists of six subsystems that combine to provide a highly capable launch system that expands the operational capability of future carriers to permit increased sortie rates while reducing manpower and costs. These six systems are: 1. The Prime Power Interface Subsystem (PPIS) draws from the ship's power grid and charges energy storage devices; 2. The Energy Storage Subsystem (ESS) stores energy kinetically in generators, and releases energy upon the initiation of a launch; 3. The Energy Distribution Subsystem (EDS) distributes the stored energy to the appropriate launcher power conversion system; 4. The Power Conversion Subsystem (PCS) controls the power pulse and delivers it to the launch motor; 5. The Launch Motor Subsystem (LMS) is a linear induction machine that provides thrust to the aircraft; and 6. The launch Control Subsystem (LCS) provides real-time active control of the launch process.
The project was started in the summer of 2004 and as of press-time is 99-percent complete. The new U.S.S. Ford aircraft carrier, slated to be launched in 2014 or 2015, will be America's first carrier fitted with the technology.