Northgate - East Link Extension

Seattle, Washington

As the systems prime GC/CM contractor, Mass. Electric Construction Co. installed all rail systems for both the 4.3-mile Northgate Link Extension and the 14.5-mile East Link Extension.  The Northgate extension consisted of 3.8 miles of twin-bored tunnel and approximately 0.5 miles of aerial guideway.  The Eastlink extension consisted of 7.5 miles at-grade, 3.5 miles aerial guideway, one mile of existing tunnels, 0.6 miles of new tunnel, 0.8 miles of a cut and one mile of floating bridge. 

Mass. Electric’s scope of work included the complete systems package, involving train control and signaling, communications, radio, fiber, SCADA upgrades, overhead catenary and traction power. 

The Northgate project included two underground passenger stations, one elevated passenger stations, one station parking garage, two prefabricated and two stick-built traction power substations, two interlockings and four signal houses. The Eastlink project included 10 stations, two parking garages, nine prefabricated traction power substations and 24 signal houses.