...being poured in others. It’s a snapshot of various stages of a project.” In addition to all mechanical work, Skanska-Tully is self-performing concrete operations, rebar and sitework. In all, the joint venture is using 95% direct labor, which has also helped keep the project moving on schedule.

“This way, we didn’t have to go bid a bunch of jobs, hire a bunch of subs and manage a bunch of subs,” says Fusco.

Currently the team has about 650 workers on-site. Fusco anticipates total manpower will peak around 850 “once the mechanicals really get going.”

“We started at bedrock. We were able to hit the ground running”

— John Crecco
project executive
                                 Skanska Northeast

Access and site logistics have created the biggest challenges on-site. The massive 400,000-sq-ft footprint is still considered small for a project so large it requires nine cranes; the three tower cranes and six crawlers are the most cranes on any jobsite in the city, says Skanska’s Crecco.

Skanska’s team early on built an access ramp into the hole for direct delivery of mechanicals and equipment. Once the ramp was removed, the only access to the site was by stairs or by hook.

“When we had the ramp, we were able to get 95% of the foundation slabs completed,” says Crecco. “With sequencing, we were able to construct about 10% of the roof level. That allowed for greater access into the structure by driving on the roof.”

Tunnels

A joint venture of Schiavone and John P. Picone Inc., Lawrence, N.Y., completed the 865-ft-long raw-water tunnel that connects to an existing line from the aqueduct. The 12-ft-dia tunnel was built using drill-and-blast techniques, and crews were cautious to avoid disrupting water service of nearby lines.

“We were clear of all the underground water lines,” says Paul Scagnelli, chief engineer and executive vice president for Schiavone. “But they’re so close we had to be extremely careful.”

The Schiavone-Picone contract also included construction of the two tunnels to move treated water to the Jerome Park Reservoir, about a mile away. Contractors used a 13.6-ft-dia TBM to bore the 3,600-ft-long high-service and 4,270-ft-long low-service treated-water tunnels through “pretty hard rock all the way,” Scagnelli says.

But what has been one of the most locally controversial components of the project still awaits: In the fall, crews are expected to start blasting rock at the reservoir for the shaft and meter chamber, a decision staunchly opposed by the community and local leaders. The shaft, which requires removal of about 5,800 cu yd of rock, was originally planned to be built using a raise bore. When NYCDEP decided to blast the shaft to speed up construction, community members balked, filing a lawsuit to block the change of plans. Project officials say periodic blasting is more efficient and less disruptive to the community.