List of tunnels in Seattle

This is a list of tunnels built in the city of Seattle, in the U.S. state of Washington.

The Puget Sound region, where Seattle lies, has a history of glaciation that has left many hills and ridges that civil engineers have needed to traverse for transportation and utilities. Some of these tunnels are part of megaprojects.

Tunnels

Year(s) ConstructedTunnelDiameterLengthNotesReferences
1894 Lake Union Sewer Tunnel 72 in (1.8 m) 5,736 ft (1,748 m) Hand excavated
1894 South Bayview Street Tunnel 4 ft (1.2 m) x 6 ft (1.8 m) 4,526 ft (1,380 m) Hand excavated
1903–1905 Great Northern Tunnel 38 ft (12 m) 5,141 ft (1,567 m) Hand excavated
1907 Oregon and Washington Railroad Tunnel 38 ft (12 m) 900 ft (270 m) Hand excavated; never completed (filled in 1922)
1910 First Avenue Utilidor Tunnel 8 ft (2.4 m) 300 ft (91 m) Compressed air, hand
1910 4th and Connecticut Ave. Sewer 3–6 ft (0.91–1.83 m) 7,060 ft (2,150 m) Supported trench
1910 Ravenna Sewer Tunnel 80 in (2.0 m)
Relined 66 in (1.7 m)		 2,875 ft (876 m) Hand; tried tunnel boring machine
Early 1900s Wallingford Tunnel 9 ft (2.7 m) 1,803 ft (550 m) Open cut and tunnel
Early 1900s Pacific Street Tunnel 9 ft (2.7 m) 11,325 ft (3,452 m) Open cut and tunnel
1910 Lander Street Sewer 4.5–9 ft (1.4–2.7 m) 5,290 ft (1,610 m) Supported trench
1911 Fort Lawton Tunnel 10 ft (3.0 m) 9,720 ft (2,960 m) Hand dug
1911 Montlake Siphon Tunnel 4 ft (1.2 m) 2,005 ft (611 m) Hand dug
1912 Dexter and 8th Avenue Tunnel 5 ft (1.5 m) 9,315 ft (2,839 m) Hand dug
1912 Washington Park Tunnels 5 ft (1.5 m) 4,052 ft (1,235 m) Hand dug
1913 Third Avenue West Siphon Tunnel 21 ft (6.4 m) 500 ft (150 m) Hand dug
1926 Jackson Street Drainage Tunnel 4 ft × 6 ft (1.2 m × 1.8 m) 1,500 feet (460 m) Hand dug
35 psi compressed air
1930 South Hanford Street Tunnel 9 ft (2.7 m) 6,055 ft (1,846 m) Hand dug
1931 Charleston Street Tunnel 3.5 ft (1.1 m) 2,830 ft (860 m)
1936 Henderson Trunk Sewer Tunnel 60 in (1.5 m) (I.D., concrete)
48 in (1.2 m) (brick)		 3,000 ft (910 m) Hand dug
Concrete and brick
1936 Laurelhurst Trunk Sewer Tunnel 9 ft (2.7 m) 1,850 ft (560 m)
1938–1941 Mount Baker Tunnel 28 ft × 23 ft (8.5 m × 7.0 m) 1,330 ft (410 m)
1934–1942 WPA slide control drainage projects 4 ft × 6 ft (1.2 m × 1.8 m) 4,926 ft (1,501 m)
1952–1954 Battery Street Tunnel 3,140 ft (960 m) Originally named Battery Street Subway
1963 Montlake Siphon Tunnel replacements 42 in × 108 in (1.1 m × 2.7 m) 586 ft (179 m)
1965–1966 Elliott Bay Interceptor section 6 tunnel 8 ft × 12.5 ft (2.4 m × 3.8 m) 1,750 feet (530 m) Tunnelling shield
1964–1967 Lake City Sewer Tunnel 8 ft × 11 ft (2.4 m × 3.4 m) 17,570 feet (5,360 m) Close-face wheel excavator
1967–1968 Second Avenue Sewer Tunnel 8.5 ft × 12.5 ft (2.6 m × 3.8 m) 19,900 feet (6,100 m) Tunnelling shield
1960s to present University of Washington utilidors Various, 5–10 ft (1.5–3.0 m) 50,000 feet (15,000 m) total
1975 Northwest Kidney Center pedestrian tunnel 10 ft (3.0 m) horseshoe 120 ft (37 m) Bobcat loader
1983–1986 Mount Baker Tunnel expansion 65 ft (20 m) 1,330 ft (410 m) Tunnelling shield
World's largest diameter soil tunnel
1984 Seattle Public Utilities Beacon Hill Waterline/Cedar River Pipeline 12 ft (3.7 m) 150 ft (46 m)
1985 Columbia Center pedestrian tunnel 14 ft (4.3 m) horseshoe 280 ft (85 m)
1985 Virginia Mason Hospital pedestrian tunnel 10 ft (3.0 m) horseshoe 120 ft (37 m) Bobcat loader
1986 Renton Sewer Tunnel ETS-4A 12 ft (3.7 m) O.D. 2,403 ft (732 m) Drill and shoot
1986 Renton Sewer Tunnel ETS-4B 12 ft (3.7 m) O.D. 620 ft (190 m) Drill and shoot
1986 Renton Sewer Tunnel ETS-5 12 ft (3.7 m) O.D. 1,820 ft (550 m) Drill and shoot
1986 Renton Sewer Tunnel ETS-6 12 ft (3.7 m) O.D. 1,056 ft (322 m) First use of Earth Pressure Balance Machine in Seattle
1987–1988 Downtown Seattle Transit Tunnel Twin 21.25 ft (6.48 m) 13,624 ft (4,153 m) Tunnelling shield
First use of waterproofing PVC membrane in USA
1990 Fort Lawton Tunnel/West Point Sewer 15.5 ft (4.7 m) O.D. 8,400 feet (2,600 m) Partial Earth Pressure Balance Machine
1993 Royal Brougham Street Sewer Tunnel 10 ft (3.0 m) O.D. 300 ft (91 m)
1993 Lake Washington Canal Tunnel 3.3 ft (1.0 m) 1,518 ft (463 m) First slurry microtunnel in Seattle
1995 Lander Street Sewer Tunnel 10 ft (3.0 m) O.D. 130 ft (40 m)
1995 First Avenue Utilidor Tunnel 10 ft (3.0 m) 500 ft (150 m) Microtunnel
1995–1997 West Seattle Sewer Tunnel 13 ft (4.0 m) 10,500 feet (3,200 m) Partial Earth Pressure Balance Machine
Maximum 400 feet (120 m) below surface
1997 Eastlake Storm Sewer Tunnel 3.5 ft (1.1 m) 475 ft (145 m) Slurry microtunnel
2001 Justice Center Tunnel 15 ft (4.6 m) horseshoe 200 ft (61 m)
2002 Denny CSO Storage Tunnel 16.8 ft (5.1 m) O.D. 6,212 ft (1,893 m) First complete Earth Pressure Balance Machine tunnel in Seattle
2002 Henderson CSO Storage Tunnel 16.8 ft (5.1 m) O.D. 3,105 ft (946 m) Earth Pressure Balance Machine, connecting microtunnels
2006 Beacon Hill tunnel Twin 20 ft (6.1 m) 1 mi (1.6 km) Tunnel boring machine
2009–2012 University Link Tunnel Twin 20 ft (6.1 m) 3 mi (4.8 km) Tunnel boring machine
$1.9 billion megaproject
2007–2011 Brightwater Sewage Tunnel 17.5 ft (5.3 m) 13 mi (21 km) Four tunnel boring machines
Maximum depth 400 feet (120 m)
Part of $1.8 billion megaproject
2013–2018 Alaskan Way Viaduct replacement tunnel 57 feet (17 m) 2 mi (3.2 km) $4.25 billion megaproject
World's largest tunnel boring machine, 57.5 feet (17.5 m) in diameter
2014–2016 Northgate Link tunnel Twin 20 ft (6.1 m) 3.4 mi (5.5 km) Tunnel boring machine
$2.1 billion megaproject
2019– King County Ship Canal Water Quality Project 21.67 ft (6.61 m) and 8 ft (2.4 m) 2.7 mi (4.3 km) Largest tunnel boring machine named "Mudhoney" to construct combined sewer outflow storage tunnel under EPA consent decree. Two smaller machines for conveyance tunnels.

See also

Further reading

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Robinson, Robert A.; Cox, Edward; Dirks, Martin (2002), Tunneling in Seattle: A History of Innovation, North American Tunnelling Conference, Seattle, Wash., archived from the original on April 6, 2010, retrieved December 16, 2012
  2. ↑ Bridges and roadway structures, Seattle Department of Transportation, retrieved December 17, 2012
  3. ↑ Phil Dougherty (April 1, 2007), "Final phase of Seattle's Alaskan Way Viaduct opens to traffic on September 3, 1959", HistoryLink, Seattle: History Ink
  4. ↑ Jenny Hansson (September 27, 1995), "The freedom to have a tunnel map", UW Daily, retrieved December 16, 2012
  5. 1 2 3 4 5 2010 Brightwater Project Progress and Tunneling Status (PDF), King County Waste Treatment Division
  6. ↑ Featured Project: Denny Way CSO Control Project, American Underground Construction Association, retrieved December 16, 2012
  7. ↑ Mike Lindblom (April 21, 2006), Beacon Hill tunneling a breeze, The Seattle Times
  8. ↑ Scott Gutierrez (May 15, 2012), Light rail tunnels now link downtown to Capitol Hill, UW, Seattle Post-Intelligencer
  9. ↑ "University Link Extension". Sound Transit. Archived from the original on October 14, 2012. Retrieved December 15, 2012.
  10. ↑ Jack Broom (September 8, 2009). "2 tunneling machines on Brightwater sewer project are damaged — and 300 feet deep". The Seattle Times. Retrieved December 15, 2012.
  11. ↑ Scott Gutierez (August 17, 2011). "Brightwater tunneling completed this week". Seattle P-I. Retrieved December 15, 2012.
  12. ↑ Jeff Switzer (September 25, 2007), "Machine moves 100 trucks of dirt a day", Everett Herald
  13. ↑ Alaskan Way Viaduct replacement program: Tunneling, Washington State Department of Transportation, retrieved December 17, 2012
  14. ↑ "Sound Transit contractor completes mining last tunnel segment for Northgate Link Extension" (Press release). Sound Transit. September 2, 2016. Retrieved September 10, 2016.
  15. ↑ Tim Newcomb (April 19, 2021), "Seattle's Latest Tunnel Boring Machine Will Dig 2.7 Miles", Engineering News-Record
  16. ↑ "Meet our tunnel boring machines". Ship Canal Water Quality Project. Retrieved March 3, 2022.