Our Sponsors:Read more »
- Prop 1: What King County Metro hopes you won't notice
- Seattle neighborhoods in limbo
- The Daily Troll: Ross Hunter rejects Senate run. Bellevue fires a cop. Dan Lewis leaving KOMO.
- Seattle parks plan: Why does City Council want to control it?
- The Daily Troll: Prepare to be surprised on 520 bridge. Bell Street: Call that a 'park'? Frye Museum as launching pad.
- Politics in Washington: Ready for an explosion
- The Daily Troll: Bertha's latest big dig delay. Metro Transit vote: Down to the wire. Habib seeks Eastside Senate spot.
- The Daily Troll: Inslee hires coal lobbyist. Metro escalator lessons. 'Absolutely True': Idaho students can read Alexie.
- What 1 lucky Seattle immigrant's case can teach politicians
- The UX Doctor: Fixing Seattle's new parking meters
Many thanks to Herb Stark and Anne Knapp some of our many supporters.ALL MEMBERS »
- Earth Day: Real environmentalists are conservative. And live where it's green (33)
- Prop 1: What King County Metro hopes you won't notice (50)
- Seattle parks plan: Why does City Council want to control it? (28)
- Seattle neighborhoods in limbo (28)
- New survey offers tips for implementing Seattle's new city council districts (12)
- Bertha's long hibernation: Still hope for an on-time finish? (19)
- Oil, coal, gas: Export proposals are growing (8)
- What 1 lucky Seattle immigrant's case can teach politicians (12)
- First Hill residents worry about Metro Transit cuts (15)
- Metro Transit cuts ahead as vote goes heavily against tax measure (7)
Wed, Dec 12, midnight 2012
Bright paint distinguishes the different components of the SR 99 tunnel boring machine’s cutterhead, and each one serves an important function. The large yellow pieces are fixed cutters that score a groove in the soil as the machine moves forward. As the machine rotates the black disc cutters grind boulders and rocks in the soil. Both of these types of cutters are replaceable and are accessed from within the cutterhead’s arms – when one wears out a new one is put in its place. Learn more about how we’re tunneling toward a new SR 99.