PORTLAND – The city plans to restore the arched footbridge at Deering Oaks this summer and install decorative cast-iron street lamps similar to the park’s original lights.
City officials must decide how attentive they will be to historic standards and whether it will be worth the extra cost.
The main issue is whether to repair the concrete-and-stone bridge with modern patching or use a traditional method for historic structures. The traditional method would be better for retaining the bridge’s original appearance, but would cost more and require more maintenance.
The standards are high because the 51-acre park is listed on the National Register of Historic Places.
At 5 p.m. today, the city’s seven-member Historic Preservation Board will examine the bridge and examples of the two repair methods. At 7 p.m. at City Hall, the board will hold a public hearing and then decide which method to use.
The board wants to make sure that the repair project meets the goal of preserving the historic nature of the bridge, said Deb Andrews, who manages the historic preservation program.
“They are reasonable and balanced in their thinking,” she said of the board, which includes three architects and two contractors.
Using money from the 2009 capital improvement budget, the city has awarded a $111,000 contract to Gorham-based Knowles Industrial Service Corp. to repair the bridge, install six lights and repair the surface of the wading pool next to the man-made ravine under the bridge.
The Historic Preservation Board has interceded and may require the city to use restoration methods typical for historic buildings. That would increase the cost by $40,000 to $60,000, said Mike Bobinsky, director of the city’s Public Services Department.
The method preferred by preservationists also would require more maintenance. Bobinsky said the modern repair work would last 20 years, while the preservation method would last seven to eight years.
When the bridge was built in 1911, replacing a wooden structure, it cost the city $3,355. Over the past century, weather has worn away the outer layer of the bridge’s concrete and exposed aggregate, creating a rough texture that adds to the bridge’s visual appeal.
On Tuesday afternoon, Scott Bourgoin, a foreman for Knowles Industrial Services, was repairing two small concrete sections of the upright portions of the bridge. For the purpose of tonight’s meeting, he used both repair methods.
The modern method consisted of patching over a cracked section of concrete, then applying a sealant. The appearance and texture of the patched area were obviously different from the original concrete.
Several feet away, Bourgoin used the traditional method favored by preservationists. He patched the section with more mortar, then pressed small stones into the mortar. The result was a repair that closely matched the color and texture of the old concrete.
With more practice, Bourgoin said, he can do better. “I think I can get it a little closer” to the original, he said.
Besides the repair method, the Historic Preservation Board will decide tonight what to do about lights.
The plan calls for six lights at a total cost of about $35,000. Unlike the original glass globes installed in 1912, the new globes will be made of a vandal-proof polycarbonate.
The original lights, which were 8 feet tall, were removed in the 1970s.
Installing lights at the original height would be more expensive because it would require that two cast-iron sections be bolted together for each pole, said Andrew Lawson, a senior vice president for Knowles Industrial Services.
Six-foot-tall lights would be cheaper because the poles could be built in one piece, he said.
Also, while the 8-foot-tall lights would be harder for vandals to reach, the extra height would make it easier for vandals to rock the poles and damage them.
“There are a lot of concerns if the lights are going to be able to survive the vandals,” he said. “They may not last two weeks.”
Staff Writer Tom Bell can be contacted at 791-6369 or: firstname.lastname@example.org