A crucial swing bridge that provides a route for heavy freight, transit and emergency vehicles as well as cyclists and pedestrians is to close 7-14 October for the reinstallation of a turn cylinder.

One of the cylinders on which the Spokane Street Swing Bridge turns, Seattle.

The Spokane Street Swing Bridge in Seattle on the USA’s northwest coast is unique in that rather than rising to allow the passage of maritime traffic, the spans rotate 45 degrees. Each of the two swinging concrete spans rotates on a steel cylinder in hydraulic oil.

As part of Seattle Department of Transport’s normal maintenance the active cylinder on the east pier will be swapped out for a spare that had been under rehab. In 2018, the refurbished cylinder was removed from the west tower.

The bridge’s controls are getting an upgrade, too, this year, with the contract awarded to Taurus Power & Controls.