The Army said it plans to look at the environmental impact of basing up to three “joint high-speed vessels” in Pearl Harbor — speedy craft capable of carrying large loads, similar to the defunct Hawaii Superferry’s ships.

Last March, Hawaii Superferry shut down operations of its ship Alakai after the state Supreme Court ruled the company couldn’t operate without completing an environmental impact statement. The company filed for bankruptcy in May.

Mike Formby, deputy director of the state Department of Transportation Harbors Division, said yesterday the impacts are unclear should the Army decide to base one or more of the 338-foot catamarans in Hawai’i.

“One thing we don’t know that needs to be fleshed out is where the vessels are going to operate, if they are deployed or positioned in Pearl Harbor,” Formby said. “Are they going to go to Pōhakuloa (Training Area) on the Big Island? Are they going to use our state piers? Where are they going to offload their military equipment and troops? None of that has been discussed with the state.”

The Army published a notice in the Federal Register on Friday saying it would conduct a programmatic environmental impact statement analysis of basing up to 12 joint high-speed vessels at five locations.

Officials with the Army Environmental Command in Maryland could not be reached for comment yesterday.

The notice said the Army is working in coordination with the Navy, which is scheduled to receive 10 of the catamarans.

The environmental analysis will consider the impacts of stationing the Army catamarans in the Virginia Tidewater area; San Diego; Seattle-Tacoma, Wash.; the Pearl Harbor area; and Guam.

The joint high-speed vessel “is a strategic transport vessel designed to support the rapid transport of military troops and equipment in the U.S. and abroad,” according to a statement from the Army Environmental Command.

The shallow-draft vessel includes a weapons mount, a flight deck for helicopters, and an off-load ramp that allows vehicles to drive off the ship quickly.

The Superferry’s Alakai catamaran was 349 feet long and could carry 866 passengers and up to 282 cars. The state in July stopped pursuing an environmental impact statement after Hawaii Superferry declared bankruptcy two months earlier.

Formby, with the state DOT, said about $750,000 had been spent for an EIS, but the completion of the environmental analysis would have cost about $500,000 more.

The Alakai made its last scheduled roundtrip between O’ahu and Maui in March.

A second Superferry vessel destined for Hawai’i, the Huakai, was retrofitted with a vehicle loading ramp that would have allowed the catamaran access to large piers without having to use onshore ramps and barges financed by the state. The vehicle ramps also make the vessels more useful to the military.

Formby said he didn’t know if the Hawai’i Superferry vessels could become part of the military’s joint high-speed vessel plan.

“There was some initial discussion that the (Pentagon) might have been interested in chartering one or both of the vessels as interim use until the (joint high-speed vessels) come off the production line,” Formby said.

He added that he hasn’t “seen anything to indicate they are moving in that direction, but it was discussed.”

The Army said it will look at three options as part of the joint high-speed vessel examination.

One option is stationing five high-speed vessels at port facilities in the U.S. or its territories as well as overseas locations, with up to three vessels at any one of the locations noted above.

A second option the Army said it will examine is the basing of 12 high-speed vessels, with up to three vessels at any one location. The Army said it also would examine a “no action” alternative.

High-speed vessel detachments consist of a 31-member crew and can accommodate up to 360 additional soldiers. The vessels can reach speeds of 35 to 45 knots (40 to 51 mph) and have an equipment carrying capacity of about 700 short tons.

The vessels will require fueling-at-sea training; helicopter training; live-fire training; and high-speed, open-water training, the Army said.

The Army said the vessels will spend 150 days or more away from the home station. The home-station sites would be used to support berthing and training requirements in and around the stationing location for 170 days per year.

Military joint high-speed vessels have periodically been in Hawai’i for testing and training before.

The HSV-2 “Swift,” a 320-foot all-aluminum catamaran, was in Hawai’i in 2004 for Rim of the Pacific war games, as was the HSV-X1 Joint Venture, a high-speed vessel leased by the Army, which was in the Isles for an extended period.

The Army at the time said it was interested in basing high-speed vessels in Hawai’i in part to transport its fast-response Stryker brigade of eight-wheeled vehicles.

Reach William Cole at wcole@honoluluadvertiser.com.