Bertha could soon start spinning again beneath Seattle
Feb 9, 2015, 2:50 PM | Updated: Feb 10, 2015, 7:40 am
Crews have completed the concrete cradle that will hold Bertha the tunneling machine during repairs, WSDOT announced Monday. (WSDOT)
(WSDOT)
Bertha could soon start drilling again after more than a year idle beneath the Seattle waterfront. It won’t be far, but it’s a critical next step in the oft-delayed Seattle tunnel project.
The Washington Department of Transportation announced recently contractors have finished building the 120-foot access pit that will allow crews to reach the drill’s damaged cutter head.
Related: Seattle Tunnel Partners completes digging of Bertha repair pit
Plans call for the tunnel machine to dig through the 20-foot thick concrete wall at the bottom of the pit. Crews will then remove the 57-foot diameter cutting head and a massive crane will hoist it to the surface for repairs.
On Monday, WSDOT announced it had finished the concrete for a cradle at the bottom of the pit that will hold the drilling machine during the repairs.
My cradle is done. Can’t wait to rest my head on this concrete pillow. pic.twitter.com/zQYojqU3Zx
— Bertha (@BerthaDigsSR99) February 9, 2015
“The next step is to tunnel through the concrete wall, per STP’s plans,” Alaskan Way Viaduct Replacement Program administrator Todd Trepanier says. “The length of time it takes Bertha to reach the pit will depend largely on her ability to mine through and digest the concrete. If she’s unable to mine through the wall, STP will create an opening from within the pit to give her an unobstructed path forward. Once inside the pit, crews will prepare the machine for disassembly and use the massive red gantry crane to hoist the front end of the machine to the surface for repairs.”
The world’s largest tunneling machine has been idle since it was damaged in December 2013.
Seattle Tunnel Partners, the contractor building the tunnel, won’t comment on its schedule and WSDOT says it can’t comment on the schedule until STP releases an update.
WSDOT tweeted Monday afternoon that the concrete cradle would need two days to cure, and preparations for drilling could begin soon after.
In STP’s last timeline released in November, it estimated Bertha would take four days to make her way through the wall into the access pit.
The schedule then estimated it would take approximately three months for the entire repair, and up to five months total to resume drilling on the tunnel.
As of now, STP still hopes to complete the tunnel by August of 2017.
