Latest updates on the Alaskan Way Viaduct Replacement Program
Bertha, the SR 99 tunneling machine, is easily the most recognizable tool being used on the SR 99 Tunnel Project. But she’s not the most important tool.
That distinction belongs to our 1,373-page contract with Seattle Tunnel Partners (STP), the joint venture we hired to design and build the tunnel. The contract can’t bore a tunnel or build the highway within it, but it can perform the project’s most vital function: protecting taxpayers.
On most highway projects, … more
While we’re working with our contractor, Seattle Tunnel Partners (STP), to get Bertha moving again, we’re also doing a significant amount of work elsewhere on the project. In fact, the vast majority of the 300 people who work on the tunnel each day aren’t anywhere near Bertha.
Here are some of the things they’ve been up to:
Building the tunnel’s south portal
It’s hard to tell when you’re driving by on SR 99, but a good portion of the tunnel& … more
The Washington State Department of Transportation is working to build a safer, more durable, effective transportation system for our citizens. All across the state – from Bellingham to Vancouver, Forks to Spokane – we manage hundreds of important transportation projects each year to upgrade or replace aging roads and bridges, increase capacity for carrying people and freight, and create more environmentally sustainable travel options for the public.
You’ve been hearing … more
He was smiling, but you could tell he was tired. Like many of our tunneling experts, he’d been working long hours lately. Still, tired or not, he was genuinely amused when he dropped into our office to share some news.
“Did you see the Seattle Times?” he said. “People are voting on what they think stopped Bertha. (Seattle Seahawks cornerback) Richard Sherman is winning.”
“I’m glad people are having some fun with this,” he … more
On Nov. 23, crews started barging soil from the tunnel dig site to a disposal facility near Port Ludlow. Adding barges to the fleet of trucks hauling away soil has greatly improved the speed and efficiency of the tunneling operation.
The reason for that is simple: Bertha is moving a lot of soil – soil that has to be taken away to make room for more soil. If crews removing it can't keep up with Bertha, the bin where the soil is stored gets full and the machine has to slow down. … more
Over the weekend, crews closed State Route 99 through downtown Seattle for an important reason: the South Atlantic Street overpass needed space to emerge from its cocoon. Don’t worry, it wasn’t flying anywhere. And it isn’t nearly as colorful as a butterfly. Still, you’ll notice a huge difference the next time you take SR 99 through SODO.
For nearly a year, hundreds of steel and timber beams, and acres of plywood and foam spanned the highway in roughly the same … more
Seattleites were digging tunnels long before Bertha, the SR 99 tunneling machine, came along. Folks started transforming subterranean Seattle in 1894, with construction of a sewer tunnel not far from the SR 99 tunnel’s north portal construction site. Since then the city has seen – or not seen, as the case may be – construction of more than 40 miles worth of tunnels.
Last month marked the 109th anniversary of the historic breakthrough on the Great Northern Tunnel, which … more
Saturday, Oct. 19, marks the 145th birthday of Bertha Knight Landes, after whom the SR 99 tunneling machine was named.
Ms. Landes didn’t dig any tunnels, but there’s no question she broke ground. Elected mayor of Seattle in 1926, she was the first woman to lead a major American city. During her two years in office she battled bootleggers, cleaned up corruption in city government and put the city’s finances in order.
She was active outside of politics, too, playing … more
Bertha, the SR 99 tunneling machine, has passed the 200-foot mark as she continues her dig toward the north end of downtown Seattle.
By the end of her shift on Oct. 8, Bertha had traveled a total of 209 feet and the top of her cutterhead was about 20 feet below the surface. She averaged nearly 14 feet of digging per day over the past week.
Bertha is still making her way through fill soil that crews have injected with grout to provide additional strength. She’ll pass into … more
It was a good first week back on the job for Bertha, the SR 99 tunneling machine.
Bertha dug 64 feet between Sept. 23 and the end of the month, averaging about 11 feet of excavation per work day. Add that to the 24 feet she traveled prior to the monthlong stoppage in mining, and Bertha had traveled a total of 88 feet by the start of October.
The end of September brought with it an important milestone: installation of the first permanent tunnel ring. Now that Bertha is building rings … more