Bon Voyage, Big Bertha! Seattle Digs A Cave For The Future

Bon Voyage, Big Bertha! Seattle Digs A Cave For The Future

In cafes and bookstores across Seattle, advertisements for concerts and gallery shows shared space with a less common urban invitation: to a party for a really big drill.

The drill — specially designed to dig a tunnel underneath downtown Seattle, building new car capacity to replace an ageing, earthquake-damaged viaduct that has dominated Seattle’s waterfront since the 1950s — has a name (Bertha, in honour of Seattle’s first female mayor), a wisecracking Twitter account, and a smiling, shovel-wielding cartoon likeness.

Last Saturday, some 5000 people came to its going-away party, the last chance for Seattleites to see the machine that, on Tuesday morning, began grinding through the earth beneath their feet for the next year and a half. It was as much a party as any construction site can be, with food trucks and confetti amid the bulldozers and reflective vests.

Picture: WSDOT

Bertha’s certainly big enough to warrant the hoopla. The largest-diameter drill in the world (its boring face is five stories tall), it was shipped from Japan to Seattle in 41 separate pieces back in April; its cutterhead alone weighs almost 800 tons.

Pictures: WSDOT

The whole thing is over 90m long — and that’s not counting the 3.2km of conveyer belt that will stretch out behind it, carrying hundreds of thousands of cubic yards of sand, dirt and rock out of the tunnel and onto waiting barges.

Bertha comes with its own control room, workshop and lunchroom for the 25 workers who will work inside it (that’s right, inside–even many of the cutting surfaces are designed to be replaceable from within), as well as a pair of giant arms designed to secure the tunnel’s walls (assembled inside Bertha’s shield and installed, ring by ring, behind it as it goes).

Picture: WSDOT

Still, all the festivity — the I Heart Bertha stickers, the gee-whiz signage — couldn’t help but feel a bit forced: an effort to close the door on the long and often contentious path that led to the champagne bottle exploding across Bertha’s broad back.

The viaduct that the new tunnel is meant to replace was a 1950s answer to a 1950s traffic problem; even the city engineer at the time reportedly looked at the designs and said, “It is not beautiful.” The viaduct raised a double layer of cars, trucks and buses above the city’s centre, leaving the streets below in perpetual shadow and noise and partially cutting the city’s waterfront, with its beautiful views of Puget Sound and the Olympic Mountains, off from the rest of downtown.

Dave Bird, a general contractor who attended the launch party, said he looked forward to Seattle gaining a multi-use waterfront more like Vancouver, British Columbia’s. “Ours is just a big concrete thing with cars on it,” he told me.

Bertha began her life in Japan, constructed piece by piece, in sections.
Picture: WSDOT

In 2001, after an earthquake damaged the viaduct, it became clear that it could not withstand another strong one. And so began a decade-long process of coming up with an alternative. The city looked into another elevated road and a cut-and-cover tunnel, but voters rejected both. The deep-bore tunnel idea, too, was initially rejected as too expensive.

A number of groups pushed to simply remove the viaduct without building a direct alternative, arguing that surface streets, improved transit, and other, upgraded routes could absorb the viaduct’s traffic, and that other cities had removed downtown freeways without ill effects.

Arguments raged in public hearings and editorial pages about which approach was the best for the city’s future: the greenest, the most effective, the most forward-thinking (which, to many, means the least car-centric). At times it felt like a debate not about a commuting route, but about the soul of the city.

Bertha is assembled inside her future shaft in Seattle.
Picture: WSDOT

There are still hard feelings. Some come from those who feel that politicians rammed the tunnel idea through; from taxpayers who worry the dig will be a boondoogle; from transit advocates who mourn pouring billions of dollars into ever more infrastructure for private cars; and even from commuters who are upset to lose the viaduct at all, with its quick downtown access and beautiful view.

One woman told me that she was excited about the tunnel plan, but asked not to print that information alongside her name because “there are those in my life who are still extremely angered about it, who cry when they think about anything to do with the tunnel.”

At the launch party though, there were plenty of Bertha boosters, and the emotion most in evidence was curiosity. Seattleites strolled around the site asking questions of engineers and Department of Transportation employees: How will the drilling affect buildings? How will the tunnel be ventilated? What will happen to all the dirt?

They stood in long lines to lean over catwalks, craning their cameras to capture the scope of the drill and the 24m deep pit in which it rested. Many brought children, who gaped at the sheer size of the machinery and collected stickers from a succession of information stations: conveyor system, power source, cutterhead.

One sticker came from checking out some unassembled sections of a future tunnel ring — massive, curved slabs of concrete that, together, will eventually combine to form a minuscule slice of the completed tube. The sections were set out so that people could sign them or write messages — a kind of 21st-century cave art — which would be cemented underground as long as the tunnel lasts.

Many of the messages people chose to send underground with Bertha were simple: “Good luck,” “Bon voyage,” “Dig straight!” and “See you on the other side.” People wrote their names, their hometowns, their pride that they or their family members had worked on the project. Someone wrote, “Civil engineering rules!” Someone drew a bicycle and wrote, “Yah, put all the cars underground!” Someone else: “In 2013 we really loved our cars. Sorry.”

The messages were a small, surreal reminder of the future Seattleites who might someday encounter them, who will see in today’s public works a relic of how the city once envisioned, rightly or wrongly, its own future self. Their inscriptions transformed the tunnel into a time capsule, a reverse archaeological site: burying a fossil message for the future instead of digging one up from the past.

Bertha makes contact, breaking ground on Tuesday, July 30, 2013.
Pictures: WSDOT

Pictures: Brooke Jarvis