Ballard Locks’ great lock is closed today and tomorrow as crews work to install stop logs.
Contractors use a Foss 300 steam crane ship to install the protocols that can be used to stop water in an emergency. The logs can also serve as an additional overflow channel if more water needs to be spilled than the dam allows.
The large locks are open on January 24th and 25th from 7:00 a.m. to 5:00 p.m. During the closures, they replace a wire rope, overhaul part of the emergency closure system and test the system.
“In the unlikely event of a major lock gate failure and uncontrolled flow through the chamber, this system will lower a series of gates into the flow to stop it,” said Jon Hofstra, project manager for operations. “The contractor will test the system during this outage and place these gates, so-called stop logs.”
A safety review in 2011 highlighted the aging lock system as a potential problem for the ship’s canal. The large crane from the 1920s at the eastern end of the large chamber is part of the ECS – an order to replace the crane was awarded in 2017, but installation is not yet planned.
Photos from the Locks Facebook page