Virginia Class Submarine Approaches Cost Benchmarks

Defense News has an update regarding the cost of the Virginia class submarines.

Designers, managers and builders of the U.S. Navy's SSN 774 Virginia-class nuclear attack submarines say they have finally cut the program's cost to about $2 billion per sub.

"As of September, we are about $50 million away from the $2 billion submarine," Capt. Dave Johnson, the Navy's Virginia-class program manager, said Oct. 19. As of now, he said, "we are at about $2.05 billion."

The figure has been key to the Navy's hope to begin building two subs per year starting in 2012. Submarine proponents in Congress are hoping to jump-start that effort in the current defense bills, now in House-Senate conference. If they succeed, an additional sub could appear as soon as 2009.

The new Navy cost estimates are for the 2012 submarine, and assume that two subs would be ordered in that year.

Managers for General Dynamics Electric Boat, the chief design shipyard for the submarines, are optimistic they can get the cost even closer to the $2 billion goal.
With a redesigned bow and at least 150 more improvements on the way, the program is "within about $15 million," John Holmander, Electric Boat's Virginia-class program manager, said Oct. 19. "And we have actual plans that should get us to the balance."

What I find interesting is that it appears the Block III changes will both enhance capability and interoperability while reducing costs. The ASDS lockout chamber was retained despite earlier warnings it would be removed. Also interesting are the changes to the sonar and VLS.

The new LAB sonar array will substitute the sonar sphere's active/passive transducers for a listening-only hydrophone system. Replacement of the water-backed LAB array for the air-backed sonar sphere will save about $11 million per sub, wrote Johnson.

Much of those savings will come from eliminating hundreds of penetrations associated with the sphere. Electric Boat also will no longer need to shape the spheres using a very expensive and sophisticated five-axis cutting machine.

The new LAB array will feature two primary components: the passive array - using hydrophone technology from the Seawolf SSN 21-class submarines - and a medium-frequency active array.
The new hydrophones will last the planned 33-year life of the submarine, while the transducers will need replacement at about 17 years.

Another advantage, said Kurt Hesche, EB's design and engineering director for the submarines: While the sphere needed more than a thousand transducers costing more than $5,000 apiece, the LAB's 1,800 hydrophones cost only $600.

The Defense News article goes on to describe a number of changes to the VLS. The 12 Tomahawk vertical launch tubes are out, replaced by two larger tubes. The missile tubes are slightly wider modifications of the 7-foot diameter D-5 Trident ballistic missile tubes with changes similar to those done in the Ohio-class SSGN conversions.

The tubes will be newly manufactured and somewhat shorter than the Ohio tubes because of the smaller Virginia hull. Each will be able to carry a Multiple All-Up-Round Canister (MAC) fitted with six Tomahawks removing the center one for an access tube.

The missile canister will be removable from the new Virginia Payload Tubes leaving room for larger weapons or underwater vehicles. The connectors and width dimensions are the same as the tubes fitted on the Ohio SSGNs which will allow interoperability between the two submarine classes for new payloads. The new tubes will nearly double the amount of payload space of the existing tubes, going from 1,200 cubic feet to 2,300. The new missile tubes are expected to save an estimated $8 million per ship beginning with the 2012 ship.

While the article is behind the firewall at Defense News, you can find the entire Defense News article in the Monday October 22nd Office of Information News Clips.