Robbins TBM:
Model of Bertha
Robbins TBM:
Meet Bertha
Robbins TBM:
Robbins Disc Cutters
Robbins TBM:
SR 99 Becomes a Tunnel
Robbins TBM:
Robbins Meets Bertha
Robbins TBM:
Bertha is Underway
Robbins TBM:
Bertha, the World's Largest
Robbins TBM:
How High?
Robbins TBM:
Property of Hitachi
Robbins TBM:
Power of Bertha
Robbins TBM:
Osaka to Seattle
Robbins TBM:
Bertha in Deep Pit
Robbins TBM:
Are you in there Bertha?
Robbins TBM:
Back It Up
Robbins TBM:
Seattle Supports Bertha
Robbins TBM:
The Tunnel's Exterior Walls
Robbins TBM:
Ready, Set, Start
Robbins TBM:
Robbins Meets Bertha
Robbins TBM:
Robbins Meets Bertha
Robbins TBM:
Robbins Meets Bertha