Equipment Type

Bertha Repair Delayed by Shells

Video illustrates Seattle Tunnel Partners' work plan for repairing Bertha, the SR 99 tunneling machine. The plan includes four major repair and enhancement elements.
October 29, 2014

The tunneling machine will enter the 120-foot pit to allow access to the drill head.

Rod Sutton is editorial director of Construction Equipment magazine. He is in charge of editorial strategy and writes a monthly column for the magazine, The Sutton Report. He has more than 30 years in construction journalism, and has been with Construction Equipment since 2001.

Seattle's tunneling project has been delayed once again, this time by shells possibly discarded by indigenous tribes or earlier settlers. No human remains have been found.

That's right, the Bertha fiasco has added another chapter.

Bertha is the moniker supplied to the tunneling machine brought in to dig what will eventually be a four-lane toll tunnel. The machine has its own Twitter account, @BerthaDigsSR99, and recently posted a photo of the pit that is being dug to repair the machine. In case you've lost track, the machine has been stalled for months and is unable to continue tunneling.

The plan to repair Bertha involves digging a 120-foot pit next to the drill head, which will allow the machine to penetrate the wall of the pit and expose the damaged drill head. Then an  elaborate lifting process will raise the head to ground level where it will be disassembled and repaired. This video show the process.

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