Traffic Impacts for Final Phase of H-Frame System Upgrades

Drivers using I-5 and State Route 900 near Boeing Field should plan for delays and prepare to use alternate routes as Seattle City Light crews work to replace overhead utilities that span the busy highways on Fri., Oct. 24 to Sat., Oct. 25. To complete this work, City Light’s traffic control contractor will close both directions of I-5 between SR 599 and Boeing Access Road, and MLK Way (SR 900) between S 129th St and Boeing Access Road. The highway closures will provide crews with the space they need to safely replace an overhead communication and lightning protection cable.

(Traffic Impact Map for Fri., Oct. 24- Sat., Oct 25)

Closure details

Fri., Oct. 24 to Sat., Oct. 25  

  • Traffic closures on both directions of I-5 between SR 599 and Boeing Access Road and SR 900 (MLK Way). The first lane will close at 9 p.m.  All lanes will be closed by midnight and reopen by 6 a.m.
  • Both directions of MLK Way (SR 900) will be closed between S 129th St and Boeing Access Road from 11 p.m. to 6 a.m. 
  • The Interurban Avenue on-ramp to northbound I-5 and the Corson Avenue on-ramp to southbound I-5 will also be closed between 10 p.m. and 6 a.m.    

 Signed detour routes will be provided. Drivers are advised to carefully follow traffic detour routes and consider using alternate routes during construction.

City Light is working to increase the electrical capacity and reliability to the Duwamish Valley with the H-Frame Replacement and Feeder Installation Project. This is the final phase of construction to replace eight outdated H-Frame structures and cables that transmit electricity on high voltage lines across I-5 due to their age and increasing electricity demand. The project will improve system safety and increase electrical reliability for customers. For more information about this project and other City Light construction projects, please visit http://www.seattle.gov/light/aboutus/construction/.

City Light System Reliability Work Will Impact Traffic on Highway 99

Fiber Optic Upgrade Project Will Cause Rolling Slowdowns Near Boeing Field; Alternate Routes Encouraged

City Light will be enhancing electrical system reliability by upgrading the communication link between two south end substations and the utility’s system control center. The work requires pulling fiber optic communications cable across State Route 99 (SR 99) near Boeing Field. The work is being done in coordination with Washington State Department of Transportation (WSDOT) and City Light’s H-Frame/Feeder installation project currently underway in the same area.

The project is planned for October 11, 2014, from 6 a.m. to 11 a.m. Rolling slowdowns on SR 99 and traffic escorts through the construction zone for this project are necessary for motorist and worker safety. There will be up to six 15-minute rolling slowdowns during the five-hour period. Drivers are advised to carefully abide by traffic restrictions and consider using alternate routes during construction. Normal traffic flow will follow once the project is complete.

Beyond enhancing communication capabilities by keeping the system control center in touch with substations, the new fiber optics are required to monitor lights on newly placed towers near I-5.

For more information about this and other City Light construction projects, please visit http://www.seattle.gov/light/aboutus/construction/.

About Seattle City Light
Seattle City Light is the 10th largest public electric utility in the United States. It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to about 750,000 Seattle area residents. City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.

City Light Completes Phase 2 of H-Frame Project Ahead of Schedule — Planned Traffic Impacts Cancelled for Sunday (9/14) and Monday (9/15)

SEATTLE – Seattle City Light crews completed the steel pole installation two days early as part of a larger project to replace H-Frame towers for high-voltage transmission lines in the Duwamish neighborhood.

With the second phase of work done ahead of schedule, traffic restrictions planned on the southbound MLK/SR900 on-ramp and southbound MLK/SR900 Sunday and Monday night have been cancelled.

Seattle City Light will work with WSDOT to schedule the final phase of work that is necessary to complete the project.

City Light is replacing eight outdated H-Frame structures and cables that transmit electricity on high voltage lines across I-5 due to their age and increasing electricity demand. The project will improve system safety and increase electrical reliability for customers.

For more information about this and other City Light construction projects, please visit http://www.seattle.gov/light/aboutus/construction/.

About City Light

Seattle City Light is the 10th largest public electric utility in the United States. It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to about 750,000 Seattle area residents. City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.

 

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City Light Completes Phase 1 of H-Frame Project Ahead of Schedule

Seattle City Light crews completed the removal of high-voltage transmission wires one day early Monday morning as part of a project to replace H-Frame towers for power lines in the Duwamish neighborhood.

With the first phase of work done ahead of schedule, traffic restrictions planned on Interstate 5 tonight have been cancelled.

Seattle City Light will work with WSDOT to schedule two other phases of work that are necessary to complete the project.

City Light is replacing eight outdated H-Frame structures and cables that transmit electricity on high voltage lines across I-5 due to their age and increasing electricity demand. The project will improve system safety and increase electrical reliability for customers.

Seattle City Light is the 10th largest public electric utility in the United States. It has some of the lowest cost customer rates of any urban utility, providing reliable, renewable and environmentally responsible power to about 750,000 Seattle area residents. City Light has been greenhouse gas neutral since 2005, the first electric utility in the nation to achieve that distinction.

Flurry of Big and Tall Engineering Hits the South End

City Light workers had a busy week of big and tall engineering near Seattle’s south end, all in an effort to make our transmission system safer.

Between July 21 and July 24, City Light workers and engineers straightened out a leaning 150-foot transmission tower, installed a massive metal pole in the middle of a rail yard, and replaced an aging wooden transmission structure in a wetland.

The work was performed during a planned outage of a major transmission corridor, near Interstate 5 south of Boeing Field, and over a busy train corridor. It required a delicate dance of permits, agreements with regional agencies and community outreach in a diverse neighborhood with territorial views.

All of it is part of a larger project to upgrade the aging structures and cables connecting the Creston-Nelson substation in the Rainier View neighborhood with the Duwamish substation to the west.

The first and probably trickiest part involved a transmission lattice tower on the west side of I-5, near the Martin Luther King. Jr. Way exit. During planning for replacement of adjacent poles, engineers discovered that the tower’s foundations gradually sank over the past 30 years, causing it to lean three feet to the side.

Crew chiefs Todd Warren and Bruce Lee, their crews, and Ironworkers Curt Blazich, Shaina Cornelius and Justin Forrest took on the job, with planning and design by Civil Engineers Norm Hodges and Irv Ogi. They first built an enclosing cage and reinforced the bottom of the structure. Using 100-ton hydraulic jacks and wires, they moved the tower’s legs up 11 inches on the northeast corner, seven inches on the southeast corner and four inches on the northwest corner. When they were done, the tower was within one inch of true plumb, an amazing feat.

“This was a first for the lineworkers, including the crew chiefs, manager and myself,“ Line Supervisor Tom Caddy said.

At the same time, workers led by Crew Chiefs Anthony Borgioli, James Alexander and Kath Johnsen got going on the installation of a 150-foot tall metal monopole in the middle of the Burlington Northern Santa Fé (BNSF) train yard. The pole raises the lines to allow BNSF to safely use a new crane to move cargo on and off trains under the power corridor.

The massive monopole was custom built for the job and installed in sections ranging from 30- to 40-feet long. Workers installed the pole and lifted and reconnected the transmission cables.

Concurrently, workers lead by Crew Chiefs Gary Legere and Ken Busby completed the replacement of an older wooden “H” frame structure (named for its shape) carrying transmission lines between the Creston-Nelson and Duwamish substations. The job was scheduled for last year, but issues related to the wetla nd terrain delayed it until now.

“All of this work happened in only four days, during the time-limited clearance on two of 230kV transmission lines,” said Mary Junttilla, project manager.

Between now and October, City Light workers and contractors will remove 10 H frames in the area and replace them with eight metal monopoles 120 to 153 tall, install new cables, and restore the landscape of the area, including enhancing existing wetlands. The upgrades will improve transmission system safety, increase reliability and flexibility and add capacity in the Duwamish industrial area.