The new seals and wearing band on the turn cylinder’s newly machined piston are critical to keeping the pressurized system working. Photo credit: SDOT.
Fri, 11/03/2023
By Ethan Bancroft for SDOT
Following the successful reinstallation of the low bridge’s turn cylinder that we removed earlier this year, the Spokane St Swing Bridge (low bridge) reopened on Tuesday, October 10, to people walking, biking, rolling, and driving!
We closed the low bridge between October 7-10 to all traffic. During this time, we completed our planned maintenance work ahead of schedule. Our bridge maintenance crew used their experience removing the turn cylinder earlier this year to maneuver it back into place more easily.
Next year (2024), we’ll reinstall the refurbished cylinder we removed during the most recent closure, and then rehabilitate the two remaining turn cylinders in the west bridge pier. Check out the photos below for some highlights from the removal and reinstallation work.
Turn cylinders push and pull on the lift cylinder to rotate the bridge span, allowing it to open and close. Earlier this year, one of the east pier’s turn cylinders was damaged when the piston head became stuck. When the unexpected damage occurred, preparations to overhaul all four of the bridge’s hydraulic turning cylinders were already underway as part of our comprehensive repair and maintenance efforts, which allowed us to complete repairs sooner than if we had been starting from scratch. Our bridge maintenance crews, along with our team of design and repair experts, redeveloped a part of the turn cylinder so that this type of malfunction is much less likely to occur in the future.
A specialty hydraulics repair shop reassembles the piston and rod and places it into the turn cylinder’s barrel. Photo credit: SDOT.
A new spherical bearing at the end of the turn cylinder’s barrel connects to a bracket within the pier house wall and anchors the barrel as the rod extends and retracts, turning the cylinder. Photo credit SDOT.
Crews removing the second turn cylinder from the pier house for rehabilitation. Photo credit: SDOT.
What’s next
Over the next two years, additional short-term closures will be required as part of our ongoing preventative maintenance work on this bridge. That means that in the future, the low bridge will be closed again to people walking, biking, rolling, and driving.
The next step in our preventative maintenance process is upgrading the control and communications system. We will share more details about the timing of this upcoming closure as planning efforts continue.
