Port told Skagit-type collapse unlikely on HR toll bridge

Port board learns it will receive state grant for waterfront trail

By BEN MCCARTY

News staff writer

The old bridge appears to be safe.

The Port of Hood River received a report Tuesday from its bridge engineer regarding the vulnerability of the Hood River Toll Bridge to accidents like the one which resulted May 23 in the collapse of a bridge over the Skagit River on Interstate 5 in Washington.

Bridge engineer David McCurry provided general analysis based on the Hood River bridge structure and type, compared to that of the Skagit River Bridge.

According to McCurry, only the lift span of the Hood River bridge contains a through-truss, the area that a semi-truck hit on the Skagit Bridge which caused the collapse.

Unlike the Hood River bridge, the Skagit bridge did not contain any contingency supports. On the Hood River bridge the two lift towers on either side of the span provide the through truss with stability and support.

According to McCurry, the main vulnerability on the Hood River bridge would be a vehicle striking one of the side rails. However, he said that a vehicle hitting the rail would be unlikely to collapse the bridge, as the bridge does not rely on the rails for stability.

Additionally, unlike the Skagit Bridge, vehicles drive above “deck trusses,” where the vehicular traffic is above the road and cannot impact the truss.

Speed limits on the Hood River bridge also help protect it. The Skagit Bridge saw vehicles crossing it at freeway speed — including the truck which hit the bracing frames leading to the collapse. Cars cross the Hood River bridge at much lower speed, which may reduce the risk of collapse since a passing vehicle cannot impact the bridge with as much “energy.”

McCurry added a disclaimer that the analysis was based on “generalization based on our knowledge of bridge types, behavior and vulnerability, and not the result of an actual analysis or engineering evaluation.”

In other business:

  • The Port received grant approval from Oregon Parks and Recreation for a bicycle-pedestrian trail along the west edge of the Nichols basin. The Port received $123,000 in grant funding, and with $35,000 in Port matching funds the 160-foot trail section will have a budget of $158,000. When completed the trail section will link up with the Hood River waterfront trail which runs west to the Hook.
  • The Port will continue its Lot 1 planning process later this month. The swath of land, which sits just north of the event site and west of slackwater beach, is one of the Port’s highest remaining development priorities. The Port will be holding a lunchtime meeting June 19 for stakeholders in the Lot 1 development. Representatives from local groups and the business community will meet with the commission to discuss their visions for Lot 1 development. It will be the first of several stakeholder meetings to be held throughout the summer.

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