Mayor Martin J. Walsh pledged Friday to restore the 63-year-old Long Island Bridge and reopen the link to an island sanctuary that houses Boston’s largest homeless shelter, programs for recovering addicts, and a camp where urban youth escape summertime violence. But that could take as long as five years.
The city closed the bridge Wednesday after a state inspection found that it was too unstable for vehicles. Repairs could cost $80 million, a daunting undertaking that has given ammunition to critics pushing for the bridge to be razed and replaced by ferry service.
But Walsh remained resolute that the city would repair the rusting, 3,450-foot steel truss structure that has been a lifeline to many.
“I’ll fix the bridge,” Walsh said. “We have a lot of social programs on Long Island. We have a shelter, and we have a reentry program that is vital to reducing crime. This is a social service island that has a lot of agencies.”
The city has invested tens of millions of dollars to keep the bridge operable, and Walsh said he will ensure that Long Island maintains its role in the city.
He said he has no plans to move the social service agencies to other locations. City officials are trying to ensure that the hundreds of people who were displaced find accommodations elsewhere in Boston, the mayor said.
The estimated five-year timeline described by Walsh raises the prospect that the homeless and others receiving services on the island will be taken in by alternative shelters for years, unless the city devises a temporary transportation option, such as a ferry.
The administration of Walsh’s predecessor, Thomas M. Menino, initiated an effort to replace the bridge, and the city’s most recent capital budget, signed by Walsh, included $35 million to cover the cost of half the project over the next five years. The goal was to get matching grants from the state and other sources.
The city also spent tens of millions of dollars on repairs over the years, with $4 million more in fixes budgeted for this year.
“Anytime we were notified that there was a problem, we took care of it,” Menino said Friday, adding that it had been prohibitively expensive to replace the bridge sooner. “It cost $80 million to do, and the state would not cooperate.”
Walsh said that when he took office, he was made aware that the bridge was deteriorating but hoped the bridge could be used a few more years while the city planned a restoration. He envisioned restoring a large section of the bridge, and city officials had been soliciting bids for a design, a spokeswoman said.
The Massachusetts Department of Transportation has agreed to pay half the design costs, which are expected to be $9 million. The state does not plan to contribute any additional funding, said Michael Verseckes, a department spokesman.
The replacement project would be done a span at a time, said Walsh spokeswoman Melina Schuler.
“We hope that half of the project costs will come from outside sources, most likely MassDOT,” Schuler said in an
The bridge was constructed in 1951 and has 16 spans, according to city documents. Bridges are typically built to last for more than 50 years, and the bridge has been rehabilitated at least seven times since 1990, according to city records.
But it was besieged with problems.
A 2007 inspection found the superstructure of the bridge in poor condition because of widespread corrosion and “section loss that has reduced the load-carrying capacity of the structure,’’ that report said.
In a 2008 report, engineering consultants hired by the city noted that the bridge might be worse than it looked because loose rust often conceals holes, The Globe reported.
In 2010, the city conducted a comprehensive inspection of the bridge, including its large metal plate connectors, city engineer Para Jayasinghe said in an account released through Walsh’s press office.
Another inspection was completed in 2012, focusing on the potentially vulnerable areas identified in the 2010 report, Jayasinghe said.
The 2012 inspection resulted in the city allocating $15 million to strengthen weakened areas of the bridge
“Deterioration, spalling, or scour have seriously affected primary structural components,’’ the 2012 report said. “Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present.”
Maintenance of the bridge was continuing this year, city officials said.
State inspectors, using new criteria to judge the reliability of bridges, determined that the rusting mass of steel plates, concrete, and rebar was no longer safe, a finding that resulted in the bridge’s closing this week.
A gate has blocked access for years, and only authorized vehicles, such as buses that bring an average of 440 homeless people a night onto the island, were allowed to pass by guards.
The bridge has long been a source of contention among Boston, Quincy, and the state. The bridge can be reached only through Quincy, but is owned and controlled by the City of Boston, which operates a guardhouse at the entrance.
When tall ships sailed into Boston Harbor in 1992, a throng of angry Quincy residents marched on the guardhouse and chanted, “The Tall Ships are coming, and so are we.”
The crowd of 400 wanted access to Long Island, the best vantage point for viewing the ships, but Boston’s mayor at the time, Raymond L. Flynn, barred Quincy residents.
During his 20 years in office, Menino developed an emotional attachment to Long Island. The former mayor and businessman Jack Connors used the far end to build Camp Harbor View, which aims to stem summer violence by giving urban youth a place to experience Boston Harbor.
Menino said his administration never entertained moving the homeless shelter and other facilities, including recovery programs, off Long Island.
“That’s the only location in the city of Boston that works,” the former mayor said.
But through the years, the city has had to grapple with a critical question: Is the bridge worth saving?
“I say forget the bridge and start looking for alternatives that can cost much less,” said Norfolk District Attorney Michael W. Morrissey, a former state senator from Quincy who has long urged the dismantling of the bridge. “But the city has never been willing to consider that.”
State Representative Bruce J. Ayers lives in Quincy about a mile from the bridge and was with the crowd that marched to the guard house in 1992. Ayers had long called for the bridge to be torn down.
“It was not only a hazard to the vehicles that drove over it, but a maritime hazard to the boats that drove under it,” Ayers said Friday. “I would have constituents — fishermen out in Squantum — that would literally witness debris falling off the bridge.”
Ayers and Morrissey have been pushing for ferry service to replace the bridge.
Ayers filed legislation that would have increased inspections of the bridge and forced the city to establish ferry service if the span were determined to be unsafe.
Walsh said he is open to ferry service, but said other matters loom, such as how to handle medical emergencies experienced by the homeless people and others on the island.
Meghan Irons can be reached at email@example.com.