Mystic - The state Department of Transportation tentatively plans to close the Mystic River drawbridge for a 54-hour period, most likely beginning on Nov. 1.
It is one of two 54-hour closures that will be needed in the last season of the rehabilitation project, which is scheduled to be completed in April 2013.
The closure is needed to install a safety barrier on the span that will prevent cars from driving off the open bridge into the water from the Stonington side if they bypass the safety gates.
Project engineer Keith Schoppe said Thursday that an official announcement of the exact closure date and times will be announced about Oct. 1.
He said the schedule will depend on contractor, tides and other factors. He said the DOT is trying to ensure the closure does not impact events such as Halloween, a Charles W. Morgan celebration and a restaurant week.
The second 54-hour closure will be needed in 2013 to conduct the final balancing of the bridge.
The final season of work calls for replacing gears and electrical systems as well as the control house atop the span.
When the project is completed in April 2013, it will bring an end to a project that took 13 years to complete.
The DOT completed the first phase of work in 2002 by replacing the bridge deck and sidewalk and repairing the massive counterweights that raise and lower the bridge. That work took two years.
The plan was to take a two-year break and then return in 2005 and 2006 to update the aging electrical and mechanical systems and repaint the span, which dates back to the 1920s. But that work was delayed until 2010 after the DOT discovered the alignment of the bridge was off because the bridge piers have settled into the river. It then had to design a solution to the problem.
Cianbro of Pittsfield, Maine, is in charge of the $14.9 million project. The DOT and Cianbro have won praise from local officials and businesses for how they have managed the project, as well as a previous phase that ended in 2002.
The project is not connected with the streetscape project on the Groton side of Mystic that upset businesses this spring and summer.