We’ve got the answers to your Bertha-related questions now that the drill has emerged from the end of the Hwy. 99 tunnel in South Lake Union. Fun fact: Garden snails travel at 10 times the average speed of the tunnel-boring machine.
What happens to Bertha once the job is done?
Bertha’s front end will be carved up and trucked away. The rest will be pulled out of the Sodo end of the tunnel. Some pieces like motors, hoses, wire and conveyor belts could be reused. Other pieces will likely be melted and recycled.
How big is Bertha?
At 57 feet, 4 inches in diameter, Bertha was the world’s largest boring machine when it began tunneling beneath Seattle. But a German company manufactured a slightly larger machine to tunnel in Hong Kong.
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How far will Bertha have gone?
How fast has Bertha traveled?
Some back-of-the-napkin math:
Bertha began tunneling on July 30, 2013. It’s expected to finish on April 4. That’s about 1,345 days, or about 32,280 hours. The machine traveled about 9,270 feet (1.755682 miles) over that period, which puts its speed at about 0.00005438915 mph.
For comparison, garden snails travel at a rate of speed more than 10 times faster (0.000621371 mph or 1 meter/hour), according to a British researcher.
How much later than the schedule is the tunnel?
In June 2013, as the machine was preparing for its big grind beneath Seattle, the tolled tunnel was scheduled to open in December 2015. That opening now is scheduled for early 2019.
How costly were delays?
Seattle Tunnel Partners has tallied $480 million of claims against the state in the Highway 99 tunnel project, but it won’t be clear for some time who will pay. WSDOT expects to pay an additional $149 million on the tunnel because of delays.
Did anything interesting happen while Bertha was tunneling?
While Bertha was underground, a few notable events took place:
- The Seahawks beat the Denver Broncos 43-8 in Super Bowl XLVIII
- The Sounders won the 2016 MLS Cup in dramatic penalty kicks
- The Mariners almost made the playoffs (not once, but twice)
- Donald Trump was elected president
- When Bertha began tunneling, the average median home value in Seattle was $298,000, according to Zillow’s home-value index. Now, it’s $420,200. Median monthly rent, as calculated by Zillow, rose from $1,636 to $2,100 over the same period.