The bulkhead doors that started to swing open instead of closed on the historic battleship Missouri were the first clue that something was amiss.

The heavy steel doors on the Mighty Mo are designed to close naturally, but gravity was having the opposite effect, and those who operate the museum and memorial at Pearl Harbor recently found that the 887-foot battleship is listing one degree to starboard.

The problem was traced to a 34,000-gallon fuel oil ballast tank that had long ago been washed clean by the Navy, and is one of 600 tanks on the ship that was the scene of Japan's surrender on Sept. 2, 1945, officially ending World War II.

Seawater had leaked in through a deteriorated rivet seal at a rate of three gallons a minute, filling the tank in a week.

"One degree seems like more than one degree (when you are on the ship)," said Don Hess, president and chief operating officer of the USS Missouri Memorial Association.

But it's a small problem that soon will be fixed, and nowhere near as big as some others now being addressed. The nonprofit museum's operators need to do rust control and painting on the superstructure above the main deck, replace nearly 53,000 square feet of teak deck planking, and in the longer term, re-coat the underwater portion of the hull, which could require drydocking.

The biggest capital improvement projects since the Missouri pulled into Pearl Harbor in 1998 as a museum are dead ahead. The costs are, well, as big as a battleship.

MAINTENANCE EXPENSIVE

Officials estimate that drydocking and lower-hull repainting could run $5 million to $8 million, superstructure rust control and painting may cost $1 million, and the decking could be anywhere from $5 million to $15 million.

A national fundraising campaign will be mounted to pay for it.

Hess and others who are part of the Mighty Mo take it all in stride, and say it's just the expected cost of doing business when you're running a circa-1944 floating battleship museum.

He puts it in terms to which owners of smaller boats can relate.

"The saying is that the two happiest days in the life of a boat owner are the day you buy the boat and the day you get rid of it," Hess said, "because in between are all the things that are normal to boat ownership, and what we're looking at are those things. We're in a marine environment, and it just costs a heck of a lot."

In addition to being the site of Japan's surrender in Tokyo Bay in 1945, the Missouri was the last battleship ever built, was called into action in the Korean War and was sent on a last combat tour to the Persian Gulf during Operation Desert Storm in 1991.

There are at least seven battleship museums around the country. None is inexpensive to run.

The Texas Parks and Wildlife Department is seeking millions for repairs to the battleship Texas, the only remaining battleship to have fought in both World War I and II. The ship is moored at the confluence of the Houston Ship Channel and San Jacinto River.

ASSESSING THE SHIP

Drydock repairs to the ship's hull cost $15 million from 1988 to 1990, according to the Houston Chronicle. Officials believe that because of hull deterioration since then, the best preservation course of action is to berth the ship on land, which could cost about $20 million, the Chronicle reported.

Museum officials with the Mighty Mo will have a better idea in December or January how much repairs will cost. The museum's board recently agreed to pay Massachusetts-based Ocean Technical Services up to $200,000 for a marine survey.

Starting in November, divers will be checking the hull and other Ocean Technical Services employees will be looking topside and in tanks and other crevices.

Hess said company owner Joe Lombardi is an expert on historic naval ships, and has surveyed other battleships, aircraft carriers and destroyers that have become museums.

"We want to take all of those things, the hull, the teak, the superstructure ... and we want to bundle that into something that's cohesive in the sense of what can we do, and how should we program it out?" said Hess, a retired Navy captain.

The teak alone will be a formidable and expensive challenge.

"It's a major endeavor. Think of 53,000 square feet of teak — and each plank has to be almost individually milled," Hess said.

The battleship North Carolina, now a museum in its namesake state, was extremely lucky in the mid-1990s when a visit by the minister of forestry from Myanmar, formerly known as Burma, led to that country donating 40 tons of teak and offering a reduced price on an additional 137 tons.

Myanmar, a major source of teak, is experiencing civil strife and there's a trade embargo, Hess notes.

Originally, the Missouri deck was solid teak, but in the 1950s that was replaced by a fir and teak laminate. The acidity corroded the teak, and let water in the seams, which led to some deck corrosion.

"The teak's over steel, so nobody's going to fall through the deck," said Bob Dewitz, chairman of the Missouri board's capital improvements committee. That steel is at least an inch thick.

Missouri workers have replaced teak planks piece by piece, but now more planks need to be replaced than they can possibly work on. It's also possible that lead-based paint will be found beneath the old teak, which would require working with cocooning tents to prevent release of that into the environment.

"Is (the teak replacement) ... something that needs to be done now? It needs to be done soon," Hess said, guessing that means within a couple of years.

PRESERVING THE PAST

The Missouri sees about 400,000 thousand visitors a year and "is doing good" financially, Hess said. "At the same time, the teak is rotting out on us."

The museum's operating budget is about $7 million a year, and more than $5 million has been spent on maintenance and upkeep of the ship since it arrived.

Hess also calls the volunteer effort "magnificent," with more than 55,000 people giving their time to help the Missouri.

Engineered woods are a possibility for the deck, but Navy purists want teak. What Hess doesn't want is for the ship to be closed to visitors, and that may mean doing sections of teak one at a time.

The other big question mark is the hull.

"At some point, every ship needs to go into drydock, but it could be a year, it could be 10 years, it could be 20 years" before it's the Missouri's next turn up, Hess said.

The last drydocking was in 1992, when the battleship was decommissioned, and the underwater hull coating was checked at the time.

"What we're trying to do is make sure that we don't wait too long," Hess said, "because there are cases of ships that waited too long and they can't be moved into drydock for fear that something is going to happen because their underwater hull is so thin."

Dewitz said the Mighty Mo's hulls are solid, but a dive assessment is needed to see if the paint is holding up and if cathodic protection using an electric current is continuing to work.

Below the water line, the battleship's hull thickness ranges from 7 or 8 inches to about 1.5 inches, officials said.

Hess said the last cost estimate he got to just be in a Pearl Harbor drydock, which was about a year and a half ago, and exclusive of all work, was $60,000 a day.

Sarah Tenney, vice president of development for the Missouri, said the fundraising for the restoration will have to be blocked off into pieces.

"It's all about phasing with fundraising," she said, adding that the marine assessment is critical to planning that out.

But raising $20 million or more in total "is a normal capital campaign number in terms of a major effort" for a museum like the Missouri, she said.

A contractor will soon be hired to fix the small leak that has led to the ship list.

The marine survey coming up, meanwhile, will be looking to the future of the battleship Missouri, which is a bookend to the USS Arizona Memorial as the start and end to World War II.

"That's one of the reasons we're doing this," Hess said. "We don't want to mortgage the future and say, 'Oh, don't worry about it,' and then, not me, but the person after that all of a sudden will say, 'It seems like we're a little lower in the water than we used to be.' We don't want that to happen. We have to make this thing last into perpetuity."

Reach William Cole at wcole@honoluluadvertiser.com.