Project Highlights / Scope of Work

  • Constructed two cast-in-place distribution splice vaults in 150’ deep shafts for major utility upgrade connecting Manhattan and the Bronx under the Harlem River
  • Constructed mechanical control building (head house) at Bronx site housing exhaust fan / ventilation system
  • Installed precast concrete roof plugs at each shaft including waterproofing and drainage
  • Installed hydraulic elevator accessing bottom of Bronx shaft
  • Installed communication and security systems
  • Performed site restoration including paving and fencing



  • Work performed in 150’ deep shaft – all materials and personnel were lowered by crane to site
  • Very tight work space
  • Coordinate work with other contractors at two separate jobsites


Project Description

Consolidated Edison has provided power in and around New York City for more than 180 years.  This project completed a major utility upgrade to their infrastructure connecting Manhattan and the Bronx under the Harlem River.  A relatively simple job was made difficult by the inherent challenges of working deep underground.

Two vertical shafts 36’ wide and 150’ deep had been drilled on either side of the river along with a tunnel connecting the two.  Our work created two cast-in-place concrete distribution splice vaults (protecting cable splices and distribution elements), one at the bottom of each shaft.  Stainless steel conduit containing the upgraded power lines was run down one shaft, through the tunnel under the river and up the other shaft.  Each side contains an electronic security system and communications network.  Both were capped with a precast concrete roof plug with waterproofing and drainage added.  Site restoration was performed including paving, sidewalks, curbs, fencing and gates.

At the Bronx site, a mechanical control building (head house) was constructed above the shaft housing a ventilation system with two massive exhaust fans.  The concrete and brick structure has architectural trim creating a pleasing aesthetic.  A hydraulic elevator was installed which accesses the splice vault. 

Working deep inside a vertical shaft is a complicated undertaking.  All materials, tools and personnel needed to be lowered by crane into the shafts each day.  This obstacle and the close quarters of the work area made coordination between our work force, the owner and the other contractors in the tunnel a crucial component of the job.