12-6-06

Walpole Bridge Choices Not Simple as 123

By Charles C. Bingaman, Contributing Writer

            Democracy was in full flower at Tuesday’s informational meeting on designs for the new Rt. 123 bridge over the Cold River with New Hampshire DOT leaders carefully taking the public pulse, competing advocates pushing for their bridgely visions, and over 100 citizens listening, questioning and commenting.

            Though DOT will make no design decision until after the official hearing Janaury 24, options it is considering remain a single span concrete butted box beam bridge, a double arched concrete bridge in appearance something like its historic predecessor, and a “composite” timber/concrete/steel structure to be proposed by Tedd Benson of Bensonwood Homes in Walpole.

            What is known for sure is:

·             >     Residents of Upper Walpole Road desperately want a new bridge as soon as possible to relieve the heavy truck traffic roaring through their neighborhood as a result of the October 2005 Cold River flood’s destroying the old bridge.

·              >      Residents of Cold River Road north of the river want both traffic relief and a return to the convenience of an operating bridge.

·             >       The Federal Emergency Management Agency (FEMA) will fund a new bridge to an estimated cost of $1.3 million, but it has to be in operation by April, 2008.  (An extension might be obtainable, but it would be highly risky to rely on getting one.)

·             >       Because asphalt producers usually close in November, any new bridge to be completed before the April 2008 FEMA deadline must actually be completed by November 2007.

NHDOT Project Engineer Robert Landry conducted the meeting and noted that he is “stretching some rules and pushing people” to get the project moving quickly for a fall 2007 completion.

Internationally renowned timber frame designer, advocate and builder Tedd Benson—a resident of Alstead and whose company is headquartered in Walpole—outlined the potential advantages of a “composite” bridge made of timber, steel and concrete.  Benson described and showed pictures of several such composite bridges he has seen in recent years in Europe that have been installed as replacements for flooded out spans.   While Benson has not yet designed a composite bridge for the Cold River, he and Bensonwood engineer Annette Dey are consulting with New Hampshire DOT engineers to make certain that any composite design they might propose would meet all required load, size, durability, maintenance and cost limits.  Most of the pictured bridges had timber/steel superstructures—something like 21st century covered bridges—that bear some of the loads and shield the roadway from the elements

“A composite bridge,” he said, “would meld the ideals of the past with realities of the present and intentions of the future. And we are confident we could complete it by November ‘07”

Benson argued that structural use of timber would add interest and beauty to the new bridge and that a composite bridge might be in place more quickly than a traditional bridge because large elements of it would be built off-site and trucked to the site for rapid assembly.  And, he noted, the composite superstructure, while hinting at the look of a traditional New England covered bridge, would transfer much of the load bearing elements from under the bridge where traditional designs must have it to above the road surface, thus adding to the water clearance distance.

John Hansel of Walpole followed Benson to the microphone and said “I am thrilled that Tedd’s here and opening our eyes to new possibilities.”  Hansel reviewed the history of Cold River bridges and suggested that, while speed of completion is important, a design that is fitting with the historical site and physically attractive setting is equally important.

DOT’s Landry reviewed the Department’s favoring of the single span bridge because “that is what we know” and because “the resources agencies—natural resources and environmental services—prefer not to put another pier in the middle of the river.”  Landry also said that the composite examples shown by Benson “may work too.  We have some concerns with them, but I think they could be worked out.”

Gerald DeMuro of South Acworth, President of Northern Heritage Mills, a sustainable resource educational organization, argued passionately for the timber composite design alternative and said that “replacing the Cold River bridge is a once in a lifetime opportunity for Walpole to be a leader, to make a statement to our children and our world that we are connected to New Hampshire forest resources that are so symbolic of—and important to—our state.”

DeMuro also noted that the stones from the demolished bridge had been inventoried and kept for possible future use on or near the new bridge or for another historically relevant project.

Landry declined to take a straw poll of the audience on whether they favored the plain single span or a possible Benson-produced composite design.  But a hasty show of hands sought by Hansel appeared to show an evenly divided audience.

Duncan Watson of Cold River Road, near the bridge site, garnered cheers when he observed that the photo of a typical DOT single span bridge, projected by DOT planners, “was appallingly boring” and that “I am wildly in favor of a wooden bridge option.”  Others in the audience asked questions suggesting that they doubted whether a composite design would have the strength or durability needed and whether it could be built within the budgetary limits. Other audience members seemed unmoved by the prospect of a modern design and, instead, preferred a traditional design.

Landry closed the meeting by telling those present that they “were part of the solution but we also have to weigh the needs of the traveling public and our natural resources agencies.”

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