Seapower - March 2009

of the new components were subjected to “accelerated life testing” and others were fitted onto the original prototypes to demonstrate their capabilities, he said.

In addition to the redesign of other key components, the water jets, engines and transmission will benefit from “evolutionary reliability enhancements that we were able to find,” Moore said.

Because the EFV’s weight can determine whether the vehicle can obtain the required water speed, the program has had a constant battle to control the initial weight and provide a weight-growth margin of 1,500 pounds to allow for future changes.

The approved design would provide 700-750 pounds of weight growth, and General Dynamics has identified additional changes that should allow the remaining weight gain, Moore said.

Part of the weight margin was achieved by lowering the EFV’s original requirements to be able to maintain its high water speed under all conditions up to sea state 3.

With $60 million in the fiscal 2009 defense bill, the EFV program has $255.4 million to start production of the seven new prototypes, the program office said.

The first new prototype is expected to be delivered in May 2010, with an additional vehicle every month after that, Moore said.

Testing would begin in the first quarter of fiscal 2011, with four of the vehicles put through mission profile tests for 500 hours each to test reliability.

Although the approved design is supposed to provide 61 hours between mission failures, Moore said they expect the prototypes to demonstrate about 30 percent to 40 percent of that. Any component failing to reach those levels will be redesigned to meet the reliability goals, he said.

The vehicles also will go through an operational assessment to allow independent evaluators to determine if they can fulfill their mission.

The two sets of tests will produce a new design with a projected reliability that will be presented to the Defense Acquisition Board in the first quarter of fiscal 2012, Moore said.

If approved for low-rate initial production, the EFV could reach IOC in 2015.

While the new models are being tested, some of the original prototypes will be used for live-fire tests to measure their combat survivability. ■

U.S. NAVY

The complex hydraulic system and computerized “fly-by-wire” control system that allow the EFV to convert from a tracked vehicle into a flat-bottomed craft that skims over the surface of the water, propelled by water jets, then shift back into a tracked vehicle at the beach have been a massive challenge in the decade-long development of the vehicle. An EFV prototype is shown here undergoing maneuverability tests on the beach at Navy Amphibious Base Little Creek, Va., in May 2007.

requires congressional notification of program cost growth of more than 15 percent over the original estimate, and calls for the termination of programs whose total cost grow by more than 25 percent.

But Pentagon procurement officials determined the EFV was essential to national security and that no alternatives could provide equal or greater military capabilities at equal or less cost. The program was ordered to virtually start over, with a comprehensive redesign focused on reliability.

Moore said a high-level Pentagon review in December determined that “General Dynamics now has a design with a predicted reliability of 61 hours mean time between operational mission failures.”

Of the 180 significant design changes made, the main purpose of 87 of the changes was reliability enhancement, while others were to improve performance or offset weight or cost that had been added by other changes, Moore said.

Some of the design changes would improve corrosion resistance in the engine compartment; others were made in the turret, primarily to improve the main gun ammunition feed system to prevent jamming.