It’s not just the latest hipster trends that are underground in Seattle these days. Bertha will continue to hibernate beneath the earth’s surface a little bit longer, city officials said. Bertha is the world’s largest machine for digging tunnels and was built specifically for the Washington State Department of Transportation (WSDOT) and this project. Bertha and its
57 foot diameter cutting edge—about the height of a five-story building—are sitting underneath Seattle
by the waterfront, and will be there until they receive necessary repairs. Bertha’s job is to carve out a new State Route 99 beneath Seattle, a highway that has been causing problems aboveground for more than 60 years. “[Bertha is] a custom-built, tube-shaped machine that bores its way through the earth, building a tunnel behind it as it goes. Industry folks call it a tunneling machine. We call her Bertha, the world’s largest tunnel digger,” the WSDOT website stated. The decision to build a replacement corridor came from an earthquake in 2001 that damaged the viaduct. The new Alaskan Way Viaduct replacement tunnel was scheduled to open by 2016. However, the job of carving out a double-decker highway tunnel cannot be completed without Bertha, and the machine is currently out of commission. Problems started back in early December, and Bertha eventually ground to a halt when trying to push through wet soil, before completely stopping when it hit a pipe. “[Seattle Tunnel Partners] (STP) said repairs will include replacing the machine’s main bearing and installing a more robust seal system that would have redundant systems and monitoring equipment. Additional repair details will be released on June 16,” KOMO News reported. As it stands, the plan is to begin repairs in the fall, and get Bertha back to work by next March. A pit will have to be dug around Bertha before the repairs can begin, similar to the pit used at Bertha’s launch site. “Tunneling beneath Seattle allows us to replace the SR 99 Alaskan Way Viaduct while minimizing closures of the highway during construction. When the tunnel opens in 2016, a two-mile stretch of SR 99 will move underground, allowing us to remove the viaduct and clear the way for new public space along Seattle’s downtown waterfront,” said the WSDOT website. The state and the contractors are at odds as to who will pay for the repair costs. The entire tunnel project itself is a $1.44 billion contract. The state insists that the contractors should pay for the extra cost, especially considering that they’re the ones operating it, and damages could be partially due to their error. “It’s a contractor-owned machine,” said Todd Trepanier of the transit agency to KOMO News. “We have an expectation that they will fulfill that contract.” The repair costs could amount to at least $125 million, more than STP paid for the machine. If responsibility fails to be attributed to either party, it could result in a legal battle that would keep Bertha underground much longer than planned. Other parts of the construction project will continue while Bertha is down and out. According to the WSDOT, the two mile tunnel underneath downtown Seattle that Bertha is digging is only a part of the project to reform State Route 99 through Seattle. The endeavor also includes a mile of highway that connects to the south entrance of the tunnel, which is located near the stadiums of Seattle. A new overpass south of downtown is also necessary, as well as the destruction of the waterfront section of the viaduct. Last but not least, the project requires a new surface street running along the waterfront that will connect downtown to State Route 99. Bertha’s route is divided into ten zones—the machine is stuck in the first one. Bertha’s need for repairs sets the project back by 16 months. However, while Bertha is getting fixed, a similar machine called Brenda will be getting started. Brenda is less than half the size of Bertha, and will be put to work on a similar project on the other side of town. Brenda will be drilling the Northgate Link tunnel, increasing mobility along the I-5 corridor by creating space for a light rail. While there is nothing that suggests that Seattle University students will be majorly affected by either project more than the city’s other residents, there have been worries regarding Brenda and the University of Washington. Brenda will be drilling near Husky stadium, and during the planning period there were concerns raised by UW officials regarding vibrations reaching the ground’s surface. “We don’t expect there will be any vibrations when they’re tunneling under campus,” said Richard Chapman, UW associate vice chancellor for capital projects to The Seattle Times. The accommodations that contractors will make to ensure the absence of vibrations include changing the vehicle intended for carrying concrete segments from a train to a rubber-tired vehicle, and by adjusting Brenda to change the way in which its hydraulic thrusters facilitate forward movement. Forward movement, of course, is something that Bertha will hopefully also be doing by next spring.