• Corporate HQ, NY
  • Melville, NY
  • Iselin, NJ
  • Ossining, NY
  • Mount Laurel, NJ

New Haven Mainline Catenary and Bridge Rehabilitation


The New Haven Main Line is one of the nation’s busiest commuter rail systems. The line’s catenary overhead wire system (OWS) was completed in 1912. HAKS provided construction engineering and inspection services for the $85 million replacement of 7 miles of OWS on the four-track system between Fairfield and Bridgeport. The new constant tension system with balance weights will eliminate sagging and maintain proper tension, which were the main causes of deterioration in the fixed-tension OWS. The system is suspended from steel lattice-type structures at approximately 300-foot intervals. 

Major construction included installation of catenary structures, foundations and associated track, signal and communication upgrades; replacement of open deck superstructures with ballasted decks; and rehabilitation of abutments of five Metro-North bridges. The project team installed 60 new steel support structures with new deep caisson foundations and rehabilitated hundreds of existing steel structures and foundations. 

Challenges included operating machinery with limited headroom while trains passed the work zone at up to 70 miles per hour. The catenary replacement involved a careful interweaving of interim and permanent traction power and overhead catenary system configurations in order to keep the railroad operational throughout construction. The project team implemented the new catenary construction in the appropriate stages, including shifting and reprofiling the existing catenary to meet new track configurations. Planned track and power outages played a critical role in maintaining train operations through the work zone during construction and minimizing train delays for commuters. Critical path method scheduling was essential to on-time delivery of the project. 

The success of this project led to a contract award for the next section of catenary replacement on two busy sections of the New Haven Line from South Norwalk to Southport and Bridgeport to Stratford, a total of 14 miles. Work on this $78 million project began in early 2014 and is scheduled for completion in 2017.