Governor Andrew Cuomo and MTA officials toured the tunnel to see the progress on Sunday. They announced that the entire project will be completed by April 2020, which is three months ahead of the projected 15- to 18-month timeline.
Construction work on the Brooklyn-bound tunnel began on September 30.
“You have to remember this was impossible to do when we first started talking about it. You couldn’t do it,” Cuomo said. “So we brought in some new minds. We brought international, technological innovation.
“And this is what you see here today,” he added. “It is a better tunnel than the original design of the tunnel.”
The governor reviewed the new construction methods employed by the MTA that were recommended in January 2019.
The techniques allow the MTA to continue running subway service on weekdays for 400,000 riders between Manhattan and Brooklyn while also rehabbing the tunnel.
Before Cuomo stepped in, the MTA had planned to close the entire L train tunnel to reconstruct the Canarsie Tube.
“This milestone for the L Project’s tunnel rehabilitation is proof that we’re ready,” said Janno Lieber, MTA chief development officer and president of MTA Capital Construction. “We’ve already been using lessons learned to improve execution of this major project.”
The revised approach includes installing a new cable racking system and new fire-resistant cables on the side of the tunnel rather than buried inside a concrete bench.
According to the governor’s office, that method increases the overall resiliency of the tunnel, and the cables are easier to maintain and upgrade.
On the cable racks, 48,440 total feet of new cables have been installed, including cables for communications, radio antennas, pump power and control and fiber optic cables.
The project also created a new wall structure with industrial fiber-reinforced polymer (FRP). The material, which is also meant to carry the heavy loads of bridges in transportation facilities, was used to create structured panels that wrapped around the damaged bench wall.
This method eliminated the need to remove existing concrete bench walls, which saved time and reduced the amount of debris and dust created, the governor’s office said.
Construction crews installed 6,305 feet of track, allowing trains to operate safely at faster speeds and reducing wear-and-tear of car equipment.
New discharge lines, pipes and controls were added to allow the pumping system to handle more flooding in the event of another natural disaster. The new system doubles the water pumping capacity and has remote monitoring and control.
Finally, 7,000 feet of specialized hydro- and geo-sensing fiber optic cables were installed in the Canarsie tunnel. The system collects data so the tube can be monitored for potential movement of the inner and outer benchwalls.
Cuomo said not only was this approach better and faster, but the fiberglass-reinforced polymer on the wall will last 100 years.
“It’s just a safer tunnel than ever before, so it’s a better design,” he said.
As the L project moves forward, the MTA will keep all of its alternate service plans in place. Those plans include enhanced 7, G and M line service on weeknights and weekends, including extended M service.
Enhanced bus service on 14th Street will remain, including additional weeknight and weekend M14 Select Bus Service.
Finally, the free transfers will continue between the Livonia Street station on the L train and the Junius Street stop on the 3 train. Free transfers will also continue among the Broadway stop on the G, the Hewes Street station on J/M, and the Lorimer Street stop on the J/M trains.
Other planned work on the project, including three new substations to power the L train, as well as new elevators at Bedford Avenue and 1st Avenue, will move forward. They are slated for completion by November 2020.
Cuomo finished his remarks on Sunday by noting that this type of approach should be the rule rather than the exception for MTA capital projects.
“Innovation works, new technology works, finding faster, better ways works,” he said. “It’s a lesson for the whole MTA.”