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University Link Light Rail Extension

Seattle, Washington

Tunnel #2

The University Link (U-Link) project extends Sound Transit’s light rail system northward from downtown Seattle to the city’s University district.

Jacobs provided a full range of construction management (CM) services for all the U-Link contracts including overall project management, resident engineering and the full range of CM services for the tunnels and stations civil works contracts.

Co-located and fully integrated with Sound Transit, Jacobs helped deliver this $1.6 billion program six months ahead of schedule $150 million under budget.


miles of twin bored running tunnels 


underground stations


separate construction contracts


construction management consultant hours worked without accident or incident (570,746 total)

Tunnel construction of underground light rail systems in urban environments is one of the most demanding and technically complex forms of civil construction. We are pleased to be part of making mobility for the Seattle area’s residents and visitors efficient and safe.

Paul Gasson
Project Manager

Digging in to solve urban tunneling challenges

Tunneling with sparks
Husky stadium
Pavement outside stadium
Tunnel boring machine

U215 was regarded as one of the highest-risk portions of the project, both for its technical difficulty and for the risk of delaying tunnel boring

The U220 tunnel contract included a technically challenging undercrossing of the Montlake Cut with only 19 feet of cover between the bottom of the canal and the top of the tunnel.

The U230 tunnel contract combines a technically challenging tunneling alignment (undercrossing of Interstate 5 with less than 20 feet of clearance) with the challenges of tunneling in a highly urbanized metropolitan center.

The two station sites involve challenging civil and utility conditions that necessitate utility relocations and extensions to provide services to the stations during construction and operation of the finished systems.

Additional considerations:

  • Urban tunneling underneath major residential and commercial neighborhoods
  • Critical expressway (I-5) and ship canal under crossings
  • Ground cover ranging from 12 ft. to 300 ft. above the tunnel
  • Groundwater control challenges

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