Tunnel Machine Set To Dig Under Seattle, But It's Not Bertha

Apr 28, 2014

A tunnel machine is set to resume digging beneath the streets of Seattle in mid-June.

No, it's not Bertha. It's Brenda.

Bertha, the world's largest tunnel machine, has been stuck beneath the downtown Seattle waterfront since early December.

With all the usual fanfare surrounding the start of a megaproject, Sound Transit celebrated the imminent launch of its refurbished tunnel-boring machine. The regional transit agency calls its machine Brenda.

Sound Transit's machine, less than half the diameter of Bertha, is set to dig a light rail tunnel 3.6 miles from Northgate to Husky Stadium on the University of Washington campus.

"This, right behind me, in this project, is a real investment in mobility in the I-5 corridor," said Rep. Jessyn Farrell. "We are helping people get out of traffic, and we're going to help people get to major employers."

After a series of speeches in front of the machine, just north of its launch site near Northeast 92nd Street, Sound Transit Board Vice Chair and Everett City Councilman Paul Roberts christened Brenda with a bottle of sparkling cider. A phalanx of TV cameras recorded the moment.

None of the speeches mentioned Seattle's most famous, or infamous, tunnel-boring machine. Bertha's not expected to resume digging until March of next year.

Sound Transit officials said they don't expect a similar fate to befall Brenda: It's already proven itself digging twin tunnels from Capitol Hill to downtown Seattle.

"I think we've got a real experienced team and an experienced technology," Roberts said. "We're excited and looking forward to staying on schedule and on budget."

In December 2012, Washington state officials enjoyed a similar ceremony in Japan. They celebrated the completion of the world's largest tunnel machine.

“I can’t tell you how excited I am to be here," Linea Laird, then head of the state Route 99 tunnel project for the Washington State Department of Transportation, told the industry publication Tunnel Talk. "The success of this project is instrumental in delivering a new city of Seattle.”

“We’ve chosen the first Monday after Memorial Day weekend, June 3, to start tunneling," Chris Dixon, head of the project for Seattle Tunnel Partners, told Tunnel Talk. "Our target completion date on our target schedule’s the 21st of July, 2014, so almost 14 months of tunneling.”

Bertha hasn't come close to the schedule that Dixon laid out in Japan.

Drilling started a couple months late, on July 30, and lost another month in the fall to a longshoreman's strike. Bertha overheated and broke down in December. Officials expect it to be on its underground staycation for a total of 16 months while Seattle Tunnel Partners and Japanese manufacturer Hitachi Zosen carry out complicated steps to replace the machine's main bearing and the seals around it.

Seattle Tunnel Partners have asked the Washington State Department of Transportation to pay $188 million in extra costs, or "change orders." WSDOT officials said they have rejected 80 percent of those change orders and are reviewing the rest.

Hitachi Zosen manufactured both Bertha and Brenda.

So far, Sound Transit's newly christened machine has a better track record than Bertha's. Bertha broke down after just 1,019 feet of drilling. The much skinnier Brenda — 21 feet in diameter versus Bertha's world-record 57.5 feet — has dug two miles already under Capitol Hill. Sound Transit officials say Brenda finished that work ahead of schedule and under budget.

Sound Transit is paying its contractor — a partnership of Jay Dee Contractors, Frank Coluccio Construction and Michels Corporation — $440 million to drill two tunnels from Northgate to Husky Stadium. Extending light rail to Northgate is expected to cost $2.1 billion overall.

A second tunnel-boring machine is expected to start drilling a tunnel parallel to Brenda's in October.