It's the tunnel maker -- you can't miss it

Wednesday, July 13, 2005

By JANE HADLEY
SEATTLE POST-INTELLIGENCER REPORTER

The building of Seattle's 14-mile light rail line is about to become a lot more obvious.

A tunnel boring machine that arrived in pieces Monday on the Seattle waterfront will be the length of a football field when it is assembled near Interstate 5 over the next two months.

The gigantic machine, manufactured in Kobe, Japan, will begin boring two one-mile tunnels through Beacon Hill in October.

Between now and then, Obayashi Corp. crews will assemble the tunneling machine east of South Forest Street and Airport Way South, just north of the Tully's Coffee roasting plant. Crews using conventional equipment have already excavated soil underneath the freeway there to allow the machine to pass through. A large crane arrives next month to assist with the machine assembly.

After the boring machine is assembled, it will be "walked" a short distance on a cribbage boardlike slab to the west side of Beacon Hill at the "West Portal" to begin munching.

The boring machine itself is 40 feet long, but support equipment up to 300 feet long will trail behind as it chews its way through Beacon Hill. The support equipment will install precast tunnel sections and lay track as the boring machine forges through the hill, said Pierce County Executive John Ladenburg, chairman of Sound Transit's board.

"What's really neat is it literally creates a tunnel as it goes along," said Ladenburg, who was at the waterfront yesterday to watch cranes unload the machine pieces onto trailers. The whole machine, which involves complex laser technology to guide it, is operated by a single person, Ladenburg marveled.

"Every guy I know would want to drive this," he said.

The machine will take six months to tunnel through Beacon Hill, said King County Councilman Dwight Pelz, a Sound Transit board member who also was at the waterfront yesterday. It will emerge on the south side of South McClellan Street. At that point, the machine will be taken apart and transported back to the west side of Beacon Hill to start all over again on the second tunnel. The tunneling is expected to be finished by January 2007.

The boring machine pieces will fill up to 30 truckloads. The larger pieces will not be moved to the West Portal area until this weekend, because it will involve some lane closures and escorts, said Geoff Patrick, a Sound Transit spokesman.

"It's very exciting," Pelz said. "It's just one more sign we're actually going to build this thing."

The 14-mile light rail line, scheduled to open in mid-2009, will run from Westlake Center downtown to South 154th Street in Tukwila, but Sound Transit has said it will be able to complete extension of the line 1.7 miles to Sea-Tac Airport within six months after that.

Construction is under way on all five segments of the initial line: underground downtown, Sodo, Beacon Hill, Rainier Valley and Tukwila.

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