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thedrifter
03-07-09, 07:42 AM
EFV Redesign Makes Tracks

Mar 6, 2009
By Bettina H. Chavanne


The U.S. Marine Corps’ Expeditionary Fighting Vehicle (EFV) negotiated its latest hurdle, a Critical Design Review (CDR), in December with relative ease, clearing the way for the first hull to roll off the assembly line as a prototype in May 2010.

The CDR was what EFV Program Manager Col. Keith Moore calls “the last off-ramp” since the program emerged from its Nunn-McCurdy law violation and subsequent recertification in 2007. An Overarching Integrated Product Team gave its blessing for the program to move forward without another review of the CDR results.

Nevertheless, the Marines (and prime contractor General Dynamics) face plenty of critics. The EFV failed its first System Design and Development evaluation, requiring a redesign and an eight-year program delay. A December Congressional Research Service report, moreover, cites stunning figures: What started out as 1,025 EFVs for $8.5 billion could wind up as $13.2 billion for a little more than half as many vehicles.

A critique from Dakota Wood of the Center for Strategic and Budgetary Assessments (CSBA) suggests the Marines dump the EFV in favor of two separate platforms. “It seems that the investment in producing a vehicle that solved the ship-to-shore closure challenge has been overcome by advances in land- and sea-based weapons development,” he writes.

“People are raising their eyebrows on EFV,” says Andrew F. Krepinevich, Jr., president of the CSBA. “Because of the growing threat, the fleet is moving farther from shore, [so the EFV] has to swim farther.” And, he adds, “It’s relatively vulnerable to improvised explosive devices (IEDs).”

The biggest issue facing the Marines in the last round of reviews was whether the vehicle could satisfy the reliability key performance parameter. The EFV prototypes, built in 2003-04, have the equivalent of 25 years of use on them, but were useful for testing component-level reliability issues. “We backfit [new designs] on the old vehicles so we could get an indication of whether the fixes and redesigns were going to do what they were intended to do,” Moore says.

General Dynamics and the Marines also addressed the laundry list of problems revealed in the 2006 operational assessment, including criticism that the vehicle won’t withstand an IED blast.

“The thing we have going for us is we’re pretty heavy,” Moore says. “The heavier you are, the easier it is to deal with IEDs.”

Engineering studies uncovered that for the level of V-hull that could be retrofitted on the EFV, “you could get as good or better protection by doing a material-thickness change.” The Marines propose an add-on kit that could be used during sustained combat operations. The kit would add “substantially higher protection with just a few inches of armored plate to the bottom of the vehicle,” Moore says. But IEDs are not a big concern during the initial stages of an operation. “They don’t lend themselves as weapons of mobile offensive warfare.”

Another issue is vehicle noise, which is due to the tracks and suspension, not the engine, Moore says. “We were able to clean up the design of the track envelope, changing materials in the external drive and road wheels. The projection is that we’re just below the threshold of single hearing protection.” (For a report on operational noise and hearing loss, see Defense Technology International, November 2008, p. 37.)

Managing weight is an issue the Marines are tackling with the Army’s help. The Army has been researching a lighter-weight linked track that, if it fits on the EFV, could provide 800 lb. of weight savings. The Marines want a prototype set of the tracks in the next 12-18 months, says Moore. The requirement for the current track on the EFV is 3,000 mi., but General Dynamics may offer a track that, while it only lasts 2,000-2,500 mi., costs far less, even with replacements.

The first EFV is slated to begin testing in May 2010. As prototypes are delivered at about one a month, the Marines will run performance verification tests and a 500-hr. reliability test. “That will give us our first demonstrated new reliability numbers on a redesigned system,” Moore says. The Marines are hoping the numbers will be where they need to be. Demand for the vehicle is too high for more missteps.

Photo: USMC

Ellie