When the first steam locomotive crossed the Poughkeepsie Bridge in 1888, the massive steel-girdered span -- the first major rail crossing of the Hudson River -- was hailed as an architectural wonder. Today, its survival is a tangled political wonder.

The 6,767-foot-long giant of elaborate latticework, midway between New York City and Albany, opened Pennsylvania coal fields to the hungry industries of New England. The Northeast of the 19th century placed such importance on the structure that steel magnate Andrew Carnegie traveled to Poughkeepsie to join Matthew Vassar, founder of Vassar College, in dedicating it.

History has passed over and under the bridge. President Franklin D. Roosevelt's special trains crossed the usually freight-only bridge to reach his home at Hyde Park, within sight of the bridge on the Hudson bluffs 10 miles north.

But over the years, railroad mergers and changing freight-traffic patterns left the bridge an orphan. The Penn Central Railroad and its successor, Conrail, found it more efficient to marshal all New England-bound freight at Selkirk Yard near Albany, bypassing the bridge.

The span was closed by a major fire in 1974. Neither Penn Central nor Conrail made any effort to repair it. But the bridge refuses to die. The battle over its future only intensified after it burned.

Meanwhile, as politicians, investors and preservationists tussel over it, the bridge hangs like a huge sword of Damocles over part of the city of Poughkeepsie and navigation on the river 212 feet below, occasionally showering pieces on homes and cars.

Last November, Conrail sold the bridge -- which cost $10 million to build -- for $1 to Railway Management Associates, an anonymous limited partnership based in St. Davids, Pa. But the sale did nothing to mute the long-running battle.

The mysterious sale has preservationists wondering what the new owners plan to do with the bridge, which is on the National Register of Historic Places. The deal also has local officials worrying that they may get stuck with a white elephant.

"Railroads look to avoid demolition costs by dumping these things," said Gordon K. Cameron, executive director of the New York Bridge Authority, which operates five bridges across the Hudson north of New York City. "There doesn't seem to be anything illegal, but it's a question of morality."

"Let me tell you that if this is Conrail's way of shedding liability, in my judgment they have shed nothing at all," Poughkeepsie Mayor Thomas C. Aposporos said. "If this sale turns out to have been simply a way of avoiding responsibility, and the people of the city of Poughkeepsie are again threatened by that structure, Conrail can be assured of a lawsuit -- even if they're not the owner of record."

Poughkeepsie's corporation counsel, Richard Cantor, said the city had reason to fret about maintenance of the span, which he said is "a massive obligation" for Railway Management.

Conrail estimated the cost of demolition at $1.4 million.

It would cost $19.7 million to restore the bridge to handle trains again, according to a 1980 study by the Federal Railroad Administration. But trains would have no place to go because Conrail tore up the tracks on both banks of the Hudson before the sale.

Aposporos and preservationists said they are worried because the deed to the bridge does not reveal the names of the 15 principals of Railway Management. The partnership's agent, Gordon S. Miller, has refused to identify them or to say where the organization's three purported offices are located.

All Miller has told local officials is that his group plans to preserve the bridge and develop it into a tourist attraction during the next 10 years.

But he also has told a Poughkeepsie-based group of preservationists, the Committee to Save the Bridge, to develop their own plans for him to consider. Among the ideas being discussed is a single, self-propelled railroad car that would shuttle commuters from Ulster County on the west bank of the river to IBM and other businesses in Poughkeepsie.

Ann Loedy, head of the preservationists' committee, said she is disturbed that Miller's group apparently had no plan before buying the bridge. "I know that if I had bought a bridge, I would have had a plan in mind," she said.

Conrail has directed all calls about the bridge to the new owners or their attorney. Neither Miller nor Railway Management's attorney returned numerous calls to their office in Pennsylvania.

The bridge has had a string of owners. First, it was part of the Central New England Railway, then later absorbed into the New York, New Haven and Hartford Railroad system. In 1968, it became part of Penn Central Railroad. Conrail took over the bridge when Penn Central and other bankrupt railroads were merged into one federally run system.

"I liken the bridge to the Eiffel Tower," Loedy said. "It was built about the same time and has become a monument of sorts."

But the May 8, 1974, fire destroyed about 700 feet of ties and warped some of the bridge girders above Poughkeepsie. The span was closed.

Howard J. Leroy was driving his one-month-old Oldsmobile along State Route 9 on April 19, 1983, when a wooden railroad tie fell from the bridge and struck the right side of his windshield.

"I felt this awful boom," said Leroy, 66. "I could have been killed very easily. If it had hit on the drivers' side I would have got it right in the face."

Such incidents prompted Poughkeepsie to sue Conrail. The city won the suit in 1983, and Conrail spent $300,000 stripping the bridge of its ties and rails where they hung over land in the city.

Immediately after the city won the lawsuit, Cameron said he received a phone call from a Conrail representative offering to sell the bridge.

"I couldn't believe the guy was serious," Cameron said. "He asked if we wanted to buy the bridge by telephone. It was so informal and so kind of crazy. It was like somebody calling you to sell you the Brooklyn Bridge."

Last year, Conrail applied to the state Department of Environmental Conservation, the U.S. Coast Guard and Poughkeepsie for permits to demolish the bridge. But Conrail abandoned the plans when it sold the bridge to Railway Management for $1.

The sale infuriated Donald L. Pevsner, 40, a railroad buff and Miami attorney who obtained an option to buy the span from Conrail. He had previously helped save the Catskill Mountain Branch of the Penn Central system from destruction.

Pevsner wanted to turn the Poughkeepsie bridge into a "wonder of the world" by developing it into a tourist attraction incorporating a restaurant, shops and historical exhibits. But he said Conrail sold the bridge the day his option expired.

He charged that Railway Management has not adequately insured the bridge, and that "a catastrophic accident would quickly drain the insurance."

Richard Wolf, an attorney for Save the Bridge Committee, said Railway Management's reticence about its development plans has created a worrisome "informational gap."

"No one is accusing anyone of acting in bad faith," he said. "But when you have good-faith concerns about informational gaps, you're going to have a lot of questions.