Bloomberg Business is reporting on the epic misadventures of Big Bertha, one of the world’s biggest tunneling machines.

About 20 workers wearing hard hats and reflective vests clump together on the edge of a chasm near Seattle’s waterfront, peering down a hole 120 feet deep and 83 feet wide. The last men have been craned out of the pit in a yellow metal cage. Gulls squawk. A TV news helicopter hovers overhead.

A dozen journalists stand nearby on the bed of a truck. We’re here to see Bertha, one of the world’s biggest tunneling machines. Or at least a piece of her. A 240-foot crane is about to haul a 540,000-pound steel shield out of the ground, 20 months after Bertha started digging a highway. Almost imperceptibly, the crane starts rising.

The event, on a Thursday in mid-March, is part of a massive rescue mission to fix the $80 million machine. She broke abruptly in December 2013 after boring through just 1,000 feet, one-ninth of her job. Her seals busted, and her teeth clogged with grit and pieces of an 8-inch steel pipe left over from old groundwater tests. She stopped entirely.

The tunnel, with a budget of $1.4 billion and originally scheduled to be finished in November 2015, is two years behind schedule. The state’s contractor, a joint venture called Seattle Tunnel Partners (STP), has spent months digging to reach Bertha and crane her to the surface, where a weary Seattle awaits.

Watch as Seattle Tunnel Partners’ work plan for repairing Bertha:

Read the full article here.