Crews building the Regional Transportation District’s FasTracks West Corridor Light Rail Line placed a 600-ton, 286-ft-long bridge over Highway 6, west of Denver, over what was originally planned to be a full highway closure during the weekend of April 30.

However, RTD’s contractor finished the rollout in 14 hours, a full 30 hours ahead of schedule, without incident.

Beginning at 2:30 a.m. the crew guided the weathered steel bridge over the highway using a large dolly with two 35-ft platforms and eight axles each. The arch traveled on guided rollers, pushed by hydraulic rams that can generate 270,000 lb per sq in. of force.

“This is the first time, as far as I am aware, in the U.S. that a basket-handled, tied-arch bridge has been rolled out using this method,” said Jim Starling, RTD West Corridor project manager.

The bridge was assembled along the south side of 6th Avenue near the Simms/Union exit. RTD worked closely with the Colorado Dept. of Transportation during assembly to plan how it would place the double-track light rail bridge across the busy corridor.

“If the bridge had been constructed-in-place over the highway, we would have had to impact traffic on 6th Avenue many times over the course of construction instead of just one weekend,” said Starling. “This approach to bridge construction enabled West Corridor crews to work in a safe environment outside of traffic and significantly minimized our impacts to commuters using the 6th Avenue freeway.”


Click here to see the video by editor Melissa Leslie documenting the bridge rollout.