Refurbishment of bridge on N Line underway
Posted on 10.09.16
One of the commuter train bridges on the North Metro Rail Line will not be built new. It's being refurbished instead.
In order to transform the South Platte 3 bridge near East 78th Avenue and Steele Street for commuter rail use, crews have gone through a checklist of activities.
During summer 2015 the old rail was removed from the bridge. But the bulk of the work occurred during summer 2016.
Crews sandblasted the existing abutment and steel beams and then applied a galvanized primer and several coats of paint to the entire bridge. At that point they were ready to pour the footings that support the abutment walls.
After the footings and abutment walls were formed, drainage pipes were installed and back-filled.
Next the concrete work began, consisting of the formation of fine grade approach slabs and sleeper slabs. These slabs prevent the foundation from contracting and expanding.
Crews then installed a cover plate between the approach slab and the sleeper slab and finally they just recently finished flashing the metal, which weatherproofs the bridge.
In the near future, North Metro crews will begin installation of the duct bank, which is a part of the train control infrastructure serving as a pathway for the wire and fiber optic cables to travel between equipment signals and gates.
After the duct bank, another back-fill will take place before the installation of the track panels, ties and hand rails.
By the end of the process the old bridge will be transformed and replaced with a new commuter rail bridge ready for the North Metro trains to pass over the South Platte River as they travel from Denver Union Station.
Trains will cross over the river three times on each run along the line. Get more information about the N Line here.