A special maintenance project is slated to bring a series of overnight closures of the Hood Canal Bridge beginning Saturday, March 18 and continuing each night through Saturday, March 25.

The internal mechanics of the floating bridge’s draw span are to be rebuilt and replaced, a project that requires traffic closures and marine vessel passage limitations. All the work is scheduled to take place between 11 p.m. and 5 a.m., according to the Washington State Department of Transportation (WSDOT).

Starting Saturday, March 18, contractor crews working on the Hood Canal Bridge Special Repair Project are to begin the task of rehabilitating the structural, electrical, mechanical and hydraulics systems of the longest floating bridge (7,869 feet) located in a saltwater tidal basin, and the world’s third-longest floating bridge overall.

Crews are slated to replace or rebuild the mechanical devices that open and close the bridge, replace the hydraulic hoses and fluid, and adjust the wheels that allow portions of the bridge to move, according to WSDOT.

The work requires as many as 12 long-term overnight closures between the hours of 11 p.m. and 5 a.m., and a maximum of 20 short-term closures of as long as an hour each between midnight and 4 a.m. An overnight work schedule was chosen in order to minimize traffic impacts.

Additional periodic closures are to be announced as dates are scheduled. The project’s completion is expected in the fall of 2017.

Marine vessels may be affected by this project, according to WSDOT. While bridge operators are still be able to open the draw span up to 300 feet, there are to be times during the project when the span will not be opened to its maximum 600 feet.

The critical maintenance is intended to help prevent breaks and malfunctions in the bridge’s mechanisms, which can multiply if not prevented or addressed early. A crew error caused a mechanical problem with the draw span on July 10, 2017, which closed the bridge unexpectedly for seven hours, and was followed that month with 22 other scheduled closures for maintenance.

An average of 17,000 vehicle trips are made across the bridge on a daily basis, according to WSDOT.

“The Hood Canal Bridge is a lifeline for thousands of residents and motorists,” said John Wynands, WSDOT Olympic Region administrator, in a press release. “We know closures are disruptive and we ask for the public’s patience. Maintaining the structure and its mechanical components in a state of good repair is critical to ensuring its continued operation.”

Learn more about the bridge, including how to sign up for alerts, at wsdot.com.