New York Gov. Andrew M. Cuomo and senior Metropolitan Transportation Authority (MTA) leadership toured the completed Manhattan-bound tube of MTA’s Canarsie Tunnel where it was announced the project was set to be completed on budget and a full three months ahead of schedule in April 2020.
MTA originally planned a 15-month complete shutdown of the Canarsie Tunnel to rebuild and improve the tunnel, which sustained significant damage following 2012’s Superstorm Sandy. The governor brought together a panel of academics with engineering expertise who determined the repairs could be completed using alternative methods, allowing the tunnel to remain in service during the work.
The tunnel carries L Train passengers and utilizing the panel’s recommended construction methods to avoid a total shutdown allowed service for 90 percent of those customers to be maintained. Service along the L Train was occasionally reduced on nights and weekends to accommodate the work.
Work on the first tube was completed in five months and the governor says this accomplishment should serve as an example of how the MTA should operate in the future.
"Today we saw up close what happens when you abandon the old ways of doing things and think outside the box - you get the work done better, faster and cheaper. And in this case, you get a better and safer tunnel than before," Gov. Cuomo said. "This project will ultimately be a case study for how the MTA needs to operate going forward, especially as they implement the upcoming historic capital plan that will completely modernize the entire system and deliver the 21st century transportation service worthy of New York. I again want to thank our academic partners who collaborated to develop these innovative techniques and I commend the new MTA leadership for their work so far."
The work now completed in the first tube includes:
- New cable racking system and new fire-resistant cables: The rehabilitation plan uses a racking system to suspend fire-resistant cables on the side of the tunnel rather than buried inside a concrete bench wall. This method increases the overall resiliency of the tunnel as the cables are easier to maintain and upgrade, and are located higher in the tube, decreasing potential for damage from flooding. On the 7,110 linear feet of cable racks, 48,440 total feet of new cables have been successfully installed: communications, radio antenna, pump power and control, and fiber optic cables. Above the cable racks, 28,000 feet of new signal cables were installed. An additional 38,855 feet of other new cable was installed: tunnel lighting conduit, sound power phone, antenna and tunnel receptacle power.
- New wall structure with industrial fiber-reinforced polymer (FRP): This material, used to carry heavy loads of bridges in transportation facilities worldwide, was used to create a new wall structure along the tunnel. The tube wall structure and the bench wall are two separate pieces of the overall L tunnel structure, with the tube wall remaining sound and only the bench wall damaged from Superstorm Sandy. The FRP material was used to create structured panels, which are installed to wrap around the damaged bench wall. This new approach created a permanent wall structure, while eliminating the need to remove existing concrete bench walls, saving time and reducing the amount of debris and demolition-related dust.
- New tracks, including new plates and continuous welded rail: 6,305 track feet have been installed, including new track ties, using continuous welded rail. This rail allows trains to safely operate at faster speeds, reduces wear and tear of car equipment and lowers the associated maintenance costs. The traction power system was also replaced with new composite contact rail, new traction power negative return cable system and new traction power positive cable.
- New discharge lines, pipes and controls: The pumping system has been upgraded to handle even greater flooding from potential natural disasters. The new system more than doubles the water pumping capacity and has a remote monitoring and control system. Approximately 3,415 linear feet of discharge pipe has been installed with nine new pump manifolds.
- New fiber optic monitoring system is being calibrated: 7,000 feet of specialized hydro- and geo-sensing fiber optic cables have been installed in the first tube. The system is currently collecting baseline data so the system can be calibrated to properly monitor for potential movement of the inner and outer benchwalls. Once the same cables are installed and calibrated in the second tube, the system will automatically process and transmit data and any alerts directly to the NYCT rail control center. Regular inspections will continue while the calibration is happening.
“This milestone for the L Project's tunnel rehabilitation is proof that we're ready. We've already been using lessons learned to improve execution of this major project, and I'm looking forward to applying the same kind of collaborative and aggressive project management strategy to revolutionize the way all MTA capital projects get done," said MTA Chief Development Officer and President of MTA Capital Construction Janno Lieber.
Work on the remaining track tunnel, which carries Brooklyn-bound trains, began Sept. 30. Additional planned work for the L Project is also continuing outside of the tunnel rehabilitation. This includes three new substations to power more L train service and new elevators at the Bedford Av and 1 Av stations. These projects remain on schedule, targeted for completion by November 2020. Accessibility initiatives at 14 St-6 Av station, a new escalator at the 14 St-Union Sq station and station upgrades to select Brooklyn L stations also recently began.
MTA CEO and Chairman Patrick J. Foye commended both the governor and Lieber’s team on the successful delivery of the first part of the project. He noted the MTA will “take lessons from this work and implement them into Capital Plan projects in the new Capital Plan." The MTA Board recently approved the largest capital plan in the agency’s history. The five-year, $51.5 billion plan will invest in the region’s subways, buses and railroads to institutionalize and build on the progress of the Subway Action Plan and create a faster, more accessible and more reliable system.
