After A Close Shave, Drawbridge Working Better

By: Alan Pollock

Topics: Bridges

The drawbridge's center span is raised to allow boats to pass. ALAN POLLOCK PHOTO

CHATHAM Using a low-tech approach, contractors may have fixed the sticky Mitchell River drawbridge.

The bridge, which has a timber superstructure, periodically did not close completely, and engineers speculated that the problem was related to the wood swelling during humid or wet weather. Last Wednesday, the contractor shaved away some of the timber on the fixed portion of the bridge where it abuts the movable span. Crews also used a grinder to remove a small amount of the metal casing that receives the bridge's span locks, which act like deadbolts on a door.

Coastal Resources Director Ted Keon said the bridge has been opened and closed several times since the repairs, and the problem has not recurred. If the problem is related to swelling caused by humidity, “the swelling ultimately must reach a maximum. Whether we're there or not remains to be seen,” Keon said.

“I know MassDOT still plans to meet with their bridge engineers,” and is bringing in wood experts from the West Coast “to discuss and review whether or not there will be additional approaches to dealing with this,” Keon added.

The town has been operating the $14 million bridge for about a year, but it remains the property of MassDOT and its general contractor until town officials formally accept ownership, something that is expected to happen in October. Town officials have indicated that they won't take ownership of the bridge until the problems are resolved.