Seattle digs deep for light rail | Railway Track & Structures
(9 Dec 2013)
"The project is going fantastic," said Gray.
He attributes the well-executed mining with the project currently being more than $100 million under budget and six months ahead of schedule.
According to Gray, the project overall is 80-percent complete with U-Link's rail systems still being installed and its two stations still under construction.
"One [station] is about 80-percent complete and the other is about 25 percent. The one behind is the one where we had all the TBMs converging, so they couldn't get started on their station finishes as early as the other one," said Gray.
The stations are Capitol HIll (where the TBM's had been converging) and University of Washington.
Construction of the Northgate Link Extension
has started. It will continue northward from the UW station to stations at the University District (NE 45th St.), Roosevelt High School (NE 65th St.) and Northgate (NE 103rd St.). It will run in bored tunnels from the UW station to a portal at NE 94th St. These tunnels will be bored by 3 TBM's (Tunneling for Northgate Link
), as the University Link tunnels were, and I think that they will be bored by the same TBM's as were used for those now-bored tunnels. Even the tunnel-boring schedules look similar. Two TBM's boring at the same time between UW and some intermediate station, and one TBM boring one tunnel and then the other for the rest of the route.
The route north of NE 94th St. will be elevated, and the extension should be done by 2021.
There is a fourth TBM now in Seattle, one that is digging a replacement for the Alaskan Way viaduct: Alaskan Way Viaduct - Tunneling
(Alaskan Way Viaduct replacement tunnel - Wikipedia
) Its diameter is 57.5 feet, large enough to dig a multiple-track tunnel. The Seattle light-rail tunnels being dug are likely all single-track ones.
Elsewhere, the East Link Extension
is now in "final design".
Construction continues on the First Hill Streetcar route, and it should open by the middle of this year. The Broadway Extension is a planned northward extension from the FHS's north end for about 6 to 8 blocks. The Seattle Streetcar: First Hill Streetcar: Broadway Extension
is another planned extension, one that will connect the South Lake Union and the First Hill lines. They've decided on a route from the southwest end of the First Hill streetcar line north in 1st Ave. and northeast in Stewart St. / Olive Way or nearby to the south end of the South Lake Union line.