July 14 update: Bertha disassembly is halfway complete

Posted on Jul 14 2017 9:33 AM

Seattle Tunnel Partners is now past the halfway point in disassembling the 8,000-ton tunneling machine Bertha. All of Bertha’s cutterhead is out of the disassembly pit and crews are working their way from top to bottom, cutting sections of the machine and lifting them by crane.

Much of the machine’s trailing gear remains inside the tunnel, out of view of our time-lapse camera. Inside the tunnel, crews are cutting and hauling pieces of the trailing gear out of the tunnel via the south portal. This new time lapse video captures the work happening inside the tunnel.

Work has progressed enough inside the disassembly pit to allow STP to use Bertha’s thrust rams to pull a large section of the trailing gear into the pit. Crews will now work from both outside and inside the tunnel to continue removing the trailing gear, which will help expedite work.

Much of the conveyor system that moved extracted soils from the tunnel onto barges has also been removed. The photo below shows crews lifting the white over-water section of the conveyor last week.

A crane removing a piece of the conveyor system

While crews dismantle the machine, work continues on the road inside the tunnel. The photo below shows crews building the upper roadway inside the launch pit near the stadiums, where Bertha began her 9,270-foot tunneling journey underneath Seattle. You can monitor progress here.

Concrete pours for the future roadway deck curing in the launch pit