Overview
New York City’s water distribution infrastructure is aging and in need of repair and upgrades. To help accomplish this critical work, the City constructed a new water tunnel, City Tunnel No. 3. The tunnel runs more than 400 ft below street level, with the water brought to the surface through a series of vertical shafts. The W48th street project (MED 599) is one of many similar projects in Manhattan that have connected new distribution chambers and piping to the City Tunnel No. 3 shafts. Upon completion of these projects, the city will be able to continue to activate sections of Tunnel No. 3, and ultimately begin rehabilitating City Tunnels No.’s 1 and 2.
About the Project
The W48th street project included the installation of new trunk and distribution water mains for connection to one particular shaft of Tunnel No.3, Shaft 25B, located at 10th Avenue between W48th and W49th streets. Project specifics included the installation of 48″, 36″ and 30″ trunk water mains and associated valves and chambers; installation of 20” and 12” distribution mains; private utility upgrades, including new gas and electric lines; rehabilitation and/ or replacement of combined sewers; reconstruction of curbs, roadways and sidewalks; and extensive MPT, including work on 8th, 9th, and 10th Avenues in Manhattan.
Project Challenges & Solutions
- The MPT and staging requirement for this project were particularly demanding. The work in 9th and 10th avenues, necessitating multiple permanent long term closures, required extensive study and coordination. LiRo-Hill’s ability to work with NYCDOT OCMC allowed changes to contractual traffic stipulations that expedited the work to the benefit of the public and the agency, and allowed completion of the project ahead of schedule.
- The original contract documents included a staging scheme that was almost unworkable as it required multiple trunk main shutdowns for both 9th and 10th Avenues. LiRo-Hill worked extensively with NYCDDC, NYCDEP and the contractor’s project manager to arrive at a restaging scheme that minimized trunk main shutdowns, maximized the contractor’s productivity, and shortened the overall project duration by allowing work to continue in a more logical sequence.
- The work directly in front of several operating Broadway theaters on W48th Street was very problematic, both due to the need to work around show schedules and to coordinate the contract work with the theatres’ load in/ out of new and old shows. LiRo-Hill received accolades from the area theaters regarding the seamless manner in which extensive construction and restoration was able to be completed with little or no impact to their operations and customers.
Outcome
LiRo-Hill’s efforts served to expedite work, to circumvent potential delays and difficulties and provided the community with as little disruptions to their environment as possible.
