monster machines
The World’s Largest Tunnelling Machine is Finally Getting Rescued 

Bertha, the world’s largest tunnelling machine, has been stuck under downtown Seattle since it broke in December 2013. Engineers have had to concoct a massive and expensive rescue plan—essentially a whole construction project in itself. And yesterday, the Bertha’s broken cutter head was finally hoisted out of the Earth. Read More >>

monster machines
The Enormous Mission to Rescue the World’s Largest Tunnelling Machine

Big Bertha was all set to dig a nearly two-mile tunnel in Seattle, but just 1,000 feet (304m) into her journey she hit a mysterious object that halted her progress. Now, crews are beginning the process of rescuing her, in what could be the world's largest recovery mission. Read More >>