April 11 project update: Tool replacement complete

Posted on Apr 11 2016 9:05 AM

Seattle Tunnel Partners has now completed nearly 100 shifts of hyperbaric work inside the SR 99 tunneling machine. One of their biggest tasks – inspecting and replacing cutting tools on the machine’s face – is now complete.

Cutting tools are expected to wear down over time, and replacing them is a normal part of tunneling. Because most of the machine’s tools were replaced during the repair effort, STP chose to replace only 11 of the more than 700 tools they inspected in the weeks since the machine reached its planned maintenance stop near Yesler Way.

STP still has some routine maintenance left to complete. They have told us that the machine is functioning as intended and will soon be ready to tunnel beneath the Alaskan Way Viaduct. WSDOT will close the viaduct for approximately two weeks to allow the machine to pass beneath the structure. We will provide the public with advance notice of the closure, but the start date isn’t yet known. It will depend on how long the remaining maintenance takes to complete.

Although the closure date hasn’t been set, it’s not too early to start thinking about your commute options. Our closure page, www.99closure.org, includes maps, commute tips, information about transit reroutes and answers to frequently asked questions. We’ll continue to add information to this page in the coming weeks.

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