The new nuclear attack submarine USS Hawaii and other Virginia-class subs will be the major source of work for the Pearl Harbor Naval Shipyard in coming years, officials said.

The $2.4 billion vessel was commissioned May 5 in Groton, Conn., and is expected to arrive for the first time at its home port of Pearl Harbor in 2009.

Submarines account for about 90 percent of the work done by Pearl Harbor's shipyard, the state's largest industrial employer with a work force of 4,740.

Pearl Harbor has 16 Los Angeles-class submarines. The USS Buffalo is expected to move to Guam this summer, while the USS Jacksonville is scheduled to be shifted from Norfolk, Va., to Hawai'i in 2008.

The USS Hawaii is the third in the new Virginia class. The second submarine in the class, the USS Texas, was commissioned last September. Reports had placed its home port at either Groton or Pearl Harbor.

Although published Navy reports last year pointed to Groton as the base for the Texas, Pearl Harbor may still be in the running. Cmdr. Mike Brown, spokesman for the U.S. Pacific Fleet submarine force, yesterday said only the home port "still is a question mark."

"I have not seen a formal announcement to say that it's going to go to Groton, or any definitive location, yet," Brown said.

Adm. Gary Roughead, who this month stepped down as commander of U.S. Pacific Fleet, recently said as the new Virginia-class attack submarines continue to come on line, "you are going to see the numbers in substantial amounts out here in Pearl Harbor."

Virginia-class and Los Angeles-class submarines are basically similar, said Michael Kawachi, the shipyard's Virginia-class planning manager.

"(But) with new technologies come new challenges," Kawachi said. "There will be new equipment and different systems, which we have to learn and prepare for."

The 377-foot Hawaii is 17 feet longer than Los Angeles-class subs. Gone is the old hull-penetrating periscope, replaced by cameras and sensors mounted on masts.

The Navy expects a slight rise in shipyard workload with the Virginia-class basing. Longer term, the Navy plans to shift from an equal balance of submarines in the Atlantic and Pacific to 60 percent of its force in the Pacific.

A team of Pearl Harbor shipyard workers in February visited the USS Texas in Groton, and the shipyard is identifying changes needed to accommodate the Virginia-class subs.

The shipyard said it needs about 40,000 square feet of covered space in a single facility close to the waterfront for Virginia-class equipment storage and workspace.

The need also is part of a struggle to modernize to stay competitive with other Navy yards. Most of the buildings within the core of the shipyard and around four drydocks were built during World War I or II, and the classes of ships and many of the functions the buildings were built to support no longer exist.

"It's absolutely essential that we have the flexibility to be able to build the facilities we need near the waterfront, and that's what's been hurting us," said Kerry Gershaneck, congressional and public affairs officer for the shipyard.

Gershaneck said the Navy is working on a memorandum of agreement with the historic preservation community to determine what changes can be made.

Reach William Cole at wcole@honoluluadvertiser.com.