ConnDOT Metro-north New Haven Rail Line Substations

New Haven, CT

AI is performing resident engineering and inspection services for the replacement of six New Haven Line substations. The project includes demolition of existing electrical traction substation facilities and related structures. The project also includes construction of temporary and new substations and electrical delivery systems including underground and overhead facilities to convey power from the substations to the tracks as well as into existing facilities. Key construction tasks include civil/foundation, structural ductbanks, site work, and overhead structures. There are numerous projects ongoing within the New Haven Line that must be coordinated so that this project is not impacted. Several of the sites have restricted access and are monitored to ensure contractor compliance with construction and permanent easement agreements. 

At each location, there are underground ductbanks both in the substation area and extending out to the tracks. These have 2 to 20 conduits and are up to 4 ft. wide by 5 ft. deep. At each location, there are two or three overhead structures on each side of the tracks with a cross structure to carry the cables to the far side. There are cable drops to the catenary wires for each track. These structures require some new poles along with modifications to the existing structures. The lump sum/site items are the substation foundations, auto-transformer foundations, substation enclosure, auto-transformers, high-voltage switchgear, cables, conduits, grounding, ductbanks, and manholes. 

The substations are all 17.5 ft. wide and range from 83 ft. to 106 ft. long. They all have reinforced concrete foundations and slabs. They are founded on spread footings and gravel fill. The contractor furnishes a new enclosure plus all the switchgear inside. In addition to the substation itself, there are two auto-transformers at each location. These are exterior in a fenced-in enclosure and sit on concrete pads. Four auto-transformers are to be furnished by Metro-North. 

The contractor is refurbishing, installing, and connecting them. The auto-transformers are being turned over to the contractor as they become available. The remaining auto-transformers are to be furnished by the contractor. 


  • Duration: 2009 - Present
  • Project Scope:
    • Electrical substation demolition
    • New substation construction
    • Auto-transformer refurbishing