Beacon Hill tunnel (Seattle)

Beacon Hill tunnel
	Tunnel's west portal under an elevated portion of Interstate 5
Overview
Location	Seattle, Washington
Coordinates	47.577°N 122.320°W
Status	Active
Start	SoDo, Seattle, Washington
End	Rainier Valley, Seattle, Washington near Mount Baker station
Operation
Constructed	2005–2009
Owner	Sound Transit
Traffic	Link light rail (1 Line)
Technical
Length	1 mi (1.6 km)
Tunnel clearance	21 ft (6.4 m)[1]
Width	21 ft (6.4 m)[1]

Beacon Hill tunnel is a public transit tunnel in Seattle, Washington, carrying light rail trains on the 1 Line under Seattle's Beacon Hill between Rainier Valley and SoDo just east of Interstate 5.[1] The Beacon Hill Link Light Rail station is approximately 165 feet (50 m) underground near the midpoint of the tunnel.

Construction

Construction of the tunnel began in March 2005 and was completed in July 2009. Obayashi Corporation was the general contractor. The twin running tunnels were excavated with a tunnel boring machine (TBM) built by Mitsubishi, named the "Emerald Mole."[2] The station and crossover tunnels were constructed using the sequential excavation method (SEM), also known as the New Austrian tunnelling method (NATM).[3]

Several workers were injured and one was killed during construction of the tunnel.[4]

The tunnel was completed at a cost of $309 million, versus Obayashi's bid of $280 million.[5]

References

Beacon Hill Station and Tunnel factsheet (PDF), Sound Transit, 2008
Carl Molesworth (June 5, 2006). "Inside the Emerald Mole". Pacific Builder and Engineer. Archived from the original on 2008-02-14.
"Sound Transit digs a cutting-edge tunnel". DJC. Retrieved 2009-09-17.
Levi Pulkkinen; Larry Lange (February 7, 2007), "Worker killed in Sound Transit tunnel: Second accident in three months at light rail site", Seattle Post-Intelligencer
Eric de Place (October 2009), Sightline Report: Cost Overruns For Seattle-Area Tunnel Projects (PDF), Sightline Institute, retrieved 2013-04-04

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

[factsheet-1] Beacon Hill Station and Tunnel factsheet (PDF), Sound Transit, 2008

[2] Carl Molesworth (June 5, 2006). "Inside the Emerald Mole". Pacific Builder and Engineer. Archived from the original on 2008-02-14.

[3] "Sound Transit digs a cutting-edge tunnel". DJC. Retrieved 2009-09-17.

[4] Levi Pulkkinen; Larry Lange (February 7, 2007), "Worker killed in Sound Transit tunnel: Second accident in three months at light rail site", Seattle Post-Intelligencer

[5] Eric de Place (October 2009), Sightline Report: Cost Overruns For Seattle-Area Tunnel Projects (PDF), Sightline Institute, retrieved 2013-04-04