The Moment A Massive Tunnel Borer Breaks Through At The End Of A Tunnel

The Moment A Massive Tunnel Borer Breaks Through At The End Of A Tunnel
Bertha, one of the world's largest tunnel boring machines, has been toiling underneath Seattle for years (with some unplanned delays)

https://www.youtube.com/watch?utm_source=ifttt&v=sLum1jxW1ls April 14, 2017 at 08:02PM
via Digg https://www.youtube.com/watch?utm_source=ifttt&v=sLum1jxW1ls