War on rust


POSTED: Thursday, October 22, 2009

The battleship Missouri, a veteran of many conflicts, is in a new war against rust.

Ship workers at Pearl Harbor Naval Shipyard yesterday hung tarps, called a body glove, inside Drydock 4 to create an airtight seal of the working area around the vessel.

The body glove will keep paint, noxious gases and airborne particles from escaping when crews sandblast the ship's steel hull starting next week.

That arduous process will be done by about 400 workers laboring around the clock, blasting off paint, then adding a layer of primer within hours before the steel rusts.

The three-month, $18 million renovation began Oct. 14 when the Missouri was pulled out of Pearl Harbor's battleship row, its home for the last 11 years. The Missouri, now a floating museum, was launched nearly 66 years ago and was the site of Japan's surrender in World War II. It also participated in Desert Storm in 1991.

It's the first battleship to be drydocked at Pearl Harbor since World War II, and likely the last one in decades because the U.S. Navy has no more active battleships.

About 1,400 tons of sand will be used to strip the 887-foot-long vessel over the next two months.

On the floor of the drydock yesterday, the 45,000-ton battleship rested on 310 wooden keel blocks 6 feet tall and weighing eight tons each.

Underneath the nearly 30-story-high vessel, engineers pointed out damage to the ship since it was last drydocked in Long Beach, Calif., in 1992.

Ron Chavez, chief engineer, said the ship's corroded hull is leaking and needs preservation work for a stationary vessel that will last another 20 years.

He said at least a dozen steel caps, or cofferdams, that cover saltwater intake vents are leaking seawater.

While the ship was in operation, 156 intake vents took in salt water that was converted into fresh water for firefighting, restrooms and cooling systems.

When the ship became inactive, the intake system was shut down and the openings were covered with boxes of one-half-inch- thick steel. One of those boxes dripped water yesterday from a 1-inch hole.

Exposed rivets holding together inch-thick steel plates in the ship's hull also showed areas that may be leaking.

In addition to the hull repair, crews will install an electronic anti-corrosion system designed for a stationary ship and reseal the propeller shafts.

When repairs are nearly finished, the ship will be refloated, or bounced, and moved forward 4 feet to repair the areas covered by the keels.

A more durable paint, made for a stationary object in water, will be the ship's final touch. About 375,000 gallons of paint will cover the eight acres of surface area on the ship.