https://www.americancityandcounty.com/wp-content/themes/acc_child/assets/images/logo/footer-logo.png
  • Home
  • Co-op Solutions
  • Hybrid Work
  • Commentaries
  • News
  • In-Depth
  • Multimedia
    • Back
    • Podcast
  • Resources & Events
    • Back
    • Resources
    • Webinars
    • White Papers
    • IWCE 2022
    • How to Contribute
    • Municipal Cost Index – Archive
    • Equipment Watch Page
    • American City & County Awards
  • About Us
    • Back
    • About Us
    • Contact Us
    • Advertise
    • Privacy Statement
    • Terms of Service
American City and County
  • NEWSLETTER
  • Home
  • Co-op Solutions
  • Hybrid Work
  • Commentaries
  • News
  • In-Depth
  • Multimedia
    • Back
    • Podcasts
  • Resources/Events
    • Back
    • Webinars
    • White Papers/eBooks
    • IWCE 2022
    • How to Contribute
    • American City & County Awards
    • Municipal Cost Index
    • Equipment Watch Page
  • About Us
    • Back
    • About Us
    • Contact Us
    • Advertise
    • Cookie Policy
    • Privacy Stament
    • Terms of Service
  • newsletter
  • Administration
  • Economy & Finance
  • Procurement
  • Public Safety
  • Public Works & Utilities
  • Smart Cities & Technology
  • Magazine
acc.com


Tunnel keeps transit station environmentally sound

Tunnel keeps transit station environmentally sound

Portland's new Westside MAX (Metropolitan Area Express) adds 18 miles to the region's existing light rail line, providing modern rail access from Gresham,
  • Written by American City & County Administrator
  • 1st May 1999

Portland’s new Westside MAX (Metropolitan Area Express) adds 18 miles to the region’s existing light rail line, providing modern rail access from Gresham, east of the city, to Hillsboro on its west. “We now have 33 miles of light rail connecting the convention center, Blazer Arena, civic stadium and other major destinations,” says Tuck Wilson, project director for the Tri-County Metropolitan Transportation District. “Within two years, the line will also connect with the Portland Airport.”

The $963 million Westside extension includes a 3-mile twin-bore tunnel under Washington Park, the busiest tourist attraction in the Portland area; one underground station; 19 surface stations; four multimodal transit centers; and nine park-and-ride lots. Parsons Brinckerhoff, New York, served as the lead civil engineering consultant for most of the project and the construction management consultant for all of it.

The twin-bore tunnel segment was selected over an aboveground alignment to preserve an environmentally sensitive canyon west of Portland. It incorporates Washington Park Station which, at 260 feet below the surface, is the deepest underground transit station in the United States.

The tunnel had to be cut through three types of rock: dense Columbia River basalt; a hard, clay-like silt known as Sandy River mudstone; and Boring lava, a locally derived basalt. At the western end of the tunnel, where rock conditions changed continuously, workers excavated via drill-and-blast, while a laser-guided tunnel-boring machine was used to cut through Columbia River basalt on the eastern end.

The boring machine was custom-built with a smoother-than-usual face to prevent the cutters from becoming plugged with basalt nuggets. Noise barriers were erected around the tunnel portals to protect the surrounding neighborhood during blasting, and homes near the east portal were soundproofed with double-glazed windows and air conditioning – a first for a transit project.

Belying its subterranean location, Washington Park Station is open and spacious thanks to 34-foot-high platform caverns, generous lighting and the constant stream of fresh air that flows naturally from one portal to the other. “The station is a major attraction in itself,” Wilson says.

Artwork in the station includes a “time line” railing with glass-encased rock samples from each period in the hills’ 16-million-year history, along with drawings and descriptions etched into the station’s granite walls. “The art and architecture give it a warm, welcoming feeling,” Wilson says.

Platforms in the Washington Park Station are separated by a pillar of rock, with enough room on either side to handle the entire passenger load for which the station was designed. The pillar incorporates fire doors so that, in an emergency, either platform can serve as an area of refuge.

Two vertical shafts between the tunnel and the surface house the elevators, stairwells, and emergency ventilation and power systems. The stable rock surrounding the tunnel provides excellent natural protection from earthquakes, and special details at the interfaces between shafts and tunnels provide additional distortion tolerance and help the shafts move with the ground.

Four high-speed elevators whisk passengers from the platform to the station’s surface level in less than 15 seconds. The surface level was carefully designed to blend in with the surrounding hills. Theshowcase entry level features an outdoor amphitheater set in a garden-like setting. Up to 2,770 passengers can move through the station every hour on their way to and from the nearby Metro Oregon Zoo, World Forestry Center, Oregon Vietnam Veterans Memorial and Portland Children’s Museum.

The entire Westside line is equipped with low-floor train cars. “We had tried lifts and special platforms in the past to achieve ADA compliance, but found them slow and difficult to use,” Wilson says. “When this project was in design, we searched for a vehicle that could accept curbside boarding without a lift, to simplify boarding for the young, elderly and disabled, and to prevent delays.”

Low-floor technology removes auxiliary equipment from the underside of the transit vehicle so that the body can hang closer to the ground. In Europe, where the technology was developed, the motor is typically reduced in size, the wheels are located at the front, back and center of the cars, and electric brakes are used instead of pneumatic compressed brakes.

For the Portland system, the first in the United States to use the technology, Iselin, N.J.-based Siemens Transportation Systems built the cars with powered wheels at the front and back only. A special section with small-diameter, unpowered wheels is in the center. Two of the four doors on each side of the cars are equipped with an extending bridge plate that can be lowered to provide wheelchair access, eliminating the delays typically associated with wheelchair boarding.

The cars were built with a heavier articulation joint than their European brethren to achieve a design speed of 55 miles per hour. An operator’s cab is located at each end for fully reversible operation. The traction electrification system is conventional overhead catenary.

All elements of the new Westside line are compatible with older Banfield segments, allowing the two lines to operate as a fully integrated system. The extension, which opened last fall, has been even more successful than its planners hoped. “Our goal was to achieve a daily ridership of 20,000 by the end of the first year,” Wilson says. “We met that goal by the end of the first month.”

Tags:

Most Recent


  • Report: Local and state governments are facing a retention crisis; the worst could be yet to come
    When the pandemic struck in 2020, public retention was hit hard: jobs in local government plummeted by 8.5 percent; state employment dropped by 4.4 percent. Two years later, local and state government jobs have rebounded by about half—to 4.1 and 1.9 percent below pre-pandemic levels respectively, according to a new report from Mission Square Research […]
  • Amid an unprecedented increase in federal spending, cities and counties stand to benefit from partnerships
    The so-called “American dream” of upward mobility has more or less stagnated: Today, a little more than 40 percent of children raised at the bottom of the income ladder remain there as adults, according to Pew Charitable Trusts, and only half grow up to earn more than their parents. This data points to a concerning […]
  • hybrid technology
    Governments using technology to harness data and improve decision-making
    There’s one kind of technology that state and local governments covet, says Rob Carey, president of Cloudera Government Solutions. “While supporting multiple state and local government agencies, our team has noticed an increase in the need for hybrid cloud solutions.” A hybrid cloud is the combination of both public and private cloud deployment models. In […]
  • Seattle-Tacoma-Bellevue, WA
    Infrastructure highlighted by city leaders as top priority in analysis of 60 mayoral addresses
    After two years of ping-pong lockdown orders, mask mandates, unprecedented vaccine drives and economic uncertainty, cities across the United States are beginning to emerge in the pandemic’s aftermath, and they’re prioritizing infrastructure, according to a report published Wednesday by the National League of Cities (NLC).  “The new normal, as we now understand it, is here,” […]

Leave a comment Cancel reply

-or-

Log in with your American City and County account

Alternatively, post a comment by completing the form below:

Your email address will not be published. Required fields are marked *

Related Content

  • Public procurement can be transformative for stakeholders in a community
  • The 10 Most Sustainable Large U.S. Cities
  • How local governments can get ahead of the infrastructure wave: Strategies to mitigate risk
  • Rebounding from Message Fatigue: Emergency Alerting in a Post COVID World

White papers


How to Assemble a Rockstar Website Redesign Steering Committee

7th June 2022

Hand Hygiene: Compliance Matters

23rd May 2022

What it Takes to Build a Winning Esports Program

23rd May 2022
view all

Events


PODCAST


Young Leaders Episode 4 – Cyril Jefferson – City Councilman, High Point, North Carolina

13th October 2020

Young Leaders Episode 3 – Shannon Hardin – City Council President, Columbus, Ohio

27th July 2020

Young Leaders Episode 2 – Christian Williams – Development Services Planner, Goodyear, Ariz.

1st July 2020
view all

Twitter


AmerCityCounty

Report: Local and state governments are facing a retention crisis; the worst could be yet to come dlvr.it/SSnmS7

24th June 2022
AmerCityCounty

Amid an unprecedented increase in federal spending, cities and counties stand to benefit from partnerships dlvr.it/SSkGBn

23rd June 2022
AmerCityCounty

Governments using technology to harness data and improve decision-making dlvr.it/SSk3H0

23rd June 2022
AmerCityCounty

Infrastructure highlighted by city leaders as top priority in analysis of 60 mayoral addresses dlvr.it/SSgBck

22nd June 2022
AmerCityCounty

Oklahoma City puts the focus on employees when implementing changes in office technology dlvr.it/SSfyns

22nd June 2022
AmerCityCounty

We want to hear from you! Please take this brief survey and let us know how your organization is managing your budg… twitter.com/i/web/status/1…

22nd June 2022
AmerCityCounty

Buying smart solutions: Technology is now part of (almost) every government purchase dlvr.it/SSbj3Z

21st June 2022
AmerCityCounty

Amid tech labor shortage, outsourcing digital services could provide relief dlvr.it/SSbj23

21st June 2022

Newsletters

Sign up for American City & County’s newsletters to receive regular news and information updates about local governments.

Resale Insights Dashboard

The Resale Insights Dashboard provides model-level data for the entire used equipment market to help you save time and money.

Municipal Cost Index

Updated monthly since 1978, our exclusive Municipal Cost Index shows the effects of inflation on the cost of providing municipal services

Media Kit and Advertising

Want to reach our digital audience? Learn more here.

DISCOVER MORE FROM INFORMA TECH

  • IWCE’s Urgent Communications
  • IWCE Expo

WORKING WITH US

  • About Us
  • Contact Us

FOLLOW American City and County ON SOCIAL

  • Privacy
  • CCPA: “Do Not Sell My Data”
  • Cookies Policy
  • Terms
Copyright © 2022 Informa PLC. Informa PLC is registered in England and Wales with company number 8860726 whose registered and Head office is 5 Howick Place, London, SW1P 1WG.
This website uses cookies, including third party ones, to allow for analysis of how people use our website in order to improve your experience and our services. By continuing to use our website, you agree to the use of such cookies. Click here for more information on our Cookie Policy and Privacy Policy.
X