Ballasted track installed on Mercer Island

For the last few weeks, crews have been busily installing ballasted track between the Mercer Island Station and East Mercer Way. This is the first segment of rail to be completed on the East Link project.

Ballasted track is similar to traditional railroad construction where gravel ballast is used to create a level surface before concrete ties and rail are placed on top. Once the ballast and ties are set, crews thread long sections of steel rails through clips on each of the ties. Crews then 'flood' the rail bed with ballast to bring it flush with the top of the ties. Finally, a machine called an automatic tamper, then rolls along the rails to precisely measure the height of the rail using a laser, and adjusts the level of ties and rails as needed.

Crews will continue to install track over the coming weeks and months. Check out more photos below.

Concrete ties are lifted and placed six at a time. This machine makes sure ties are spaced correctly.

960-foot-long sections of rail are then threaded through clips on either end of the concrete tie.

Crews use a high-rail vehicle and ballast cars to 'flood' the rail with ballast.

A machine called a 'tamper' uses lasers to measure the height of the rail lifts the concrete ties to the correct height.

Limited work during the holidays

Crews will continue working over the holidays but work will be reduced and primarily limited to station areas. There will be no ramp closures during this time.