Clancy & Theys Construction Company provided general contracting for the building of the Manning Drive Steam Tunnel, Phase 2B. The project was a 1/3-mile-long utility tunnel that began near Kenan Stadium, headed south under Emergency and Manning Drives, and halfway down Hibbard Drive, where it connected to the Phase I tunnel already in operation. The work involved excavating a soil-nailed or piled and lagged trench 23 feet deep and 20 feet wide, with three wider nodes for distribution vaults as big as 46,000 cubic feet. The tunnel system is typically 9 feet x 9 feet clear inside and carries up to 42 inches of chilled water lines and 24 inches of steam lines supported on structural steel racks. Outside the tunnel, 48 conduit duct banks were run for 100 KVA and 15 KVA power, plus telecommunications ducts for fiber optics. Parallel with the tunnel is a 12-inch domestic water line, a 24-inch reuse water line, and storm sewers. A 450-foot storm line, 72 feet in diameter with five large manholes, was added to solve a long-standing flooding problem for the 65 acres that drained toward this excavation. This project tied into both ends of a new steam plant and had two shallow steam tunnels radiating out from two of the vaults. Clancy & Theys also constructed an emergency boiler plant, which was brought online in two months to serve as emergency heating backup for half of the campus.
The project also included modifications to pedestrian and vehicular traffic, along with associated protection, piping, fencing, landscaping, tunnel waterproofing, tunnel conduits, and pavement markings.
