Hellgate Line Catenary Modifications - Bronx and Westchester Counties, N.Y.
In November 2006, Kiewit began work on a 45-month, $54 million project to rehabilitate eight segments of catenary lines from New Rochelle to Sunnyside Yard. The existing systems, which were installed in the 1920s and 1930s, were due for rehabilitation because of age and as a preventative measure to ensure the catenary lines will hold in extreme weather events, such as a windstorm.
The project scope included installing 1.5 million pounds of miscellaneous and structural steel to support 15 miles of registered track; adjusting new heights and staggers on the new insulator assemblies for catenary on new and existing structures; removing the old catenary supporting system, which includes hanging beam and main messenger support cable; and establishing new controls and communications for a new crossover. Crews also installed 132 new structures around bridges to make the wire meet the track's curve criteria.
An early project milestone was the completion of an interlock to ensure that Amtrak maintained the flexibility to move its trains. Close cooperation between Amtrak and the project team ensured that the milestone was met on time.
Phase II consisted of a network of shallow pipelines that intercept the combined storm and sanitary wastewater, drop it down through shafts, and transport it to tunnels for storage until it can be treated. Work included excavation and lining of a 22-foot-diameter tunnel constructed 85 to 165 feet below ground and seven separate shafts located along the alignment.