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First Pedestrian Bridge in Place at McLean Station

Sections walked along Colshire, 123 at night.

The first section of the pedestrian bridge across Route 123 into the McLean Station, aka Tysons East Metrorail Station, is put into place. At left, workers inside the station itself watch as crews connect the bridge section to the station.

The first section of the pedestrian bridge across Route 123 into the McLean Station, aka Tysons East Metrorail Station, is put into place. At left, workers inside the station itself watch as crews connect the bridge section to the station. Chuck Samuelson/Dulles Corridor Metrorail Project

The first pedestrian bridge at a Silver Line Metrorail station is now in place.

During two dramatic overnight operations that forced the closing of busy Route 123 in the heart of Tysons Corner, the sections of the pedestrian bridge were literally walked from a staging area on Colshire Drive to Route 123 where they were installed on piers connecting the McLean Station (aka Tysons East) and a pedestrian access building at the corner of the southwest side of Route 123 at Colshire. The work took place overnights Oct. 12 and 15.

On Friday night, crews installed a huge bridge section between the McLean Station and a specially-constructed pier which was built in the median of Route 123. The second section was put into place between the pier in the median of Route 123 and the pier located off the road near the corner of Route 123 and Colshire Drive Monday night, Oct. 15.

A third and final section of the bridge will be installed off the road and require only a single lane closure.

Installation of the large segments was no small order. To expedite the process and reduce the time the roads would need to be closed, the bridge was assembled at a staging area located at the corner of Route 123 north and Colshire Drive.

It was then secured onto jacks that are mounted on a Self Propelled Modular Trailer (SPMT) system and transported from the staging area to the station.

The full height of the first transport was 43 feet, which required that the traffic lights at both Colshire Drive and Route 123 be dropped to allow the transport to pass through the intersection, and then reinstalled after the transport had finished its work. The transport was 144 feet long, 24-34 feet wide, and weighed 182,000 pounds.

The 400,000-pound, computer-driven transport moved slowly into place, escorted by the computer operator who walked by its side. The process was repeated for the second bridge section.

When this work was completed, the transport devices moved from the Route 123 site to staging areas just west of the Wiehle-Reston East Station in the median of the Dulles International Airport Access Highway where sections of the pedestrian bridges for that station have been assembled. Those bridges are to be put into place later this month.