Full Shutdown of L Train to Be Halted by Cuomo
By Emma G. Fitzsimmons and Shane Goldmacher
Jan. 3, 2019
Gov. Andrew M. Cuomo announced on Thursday that the L train subway tunnel would not fully shut down in April as planned in what would have been one of the biggest transit disruptions in New York City’s recent history.
The L train shutdown was scheduled to begin April 27 and last 15 months, crippling a key piece of the city’s transportation network. The Metropolitan Transportation Authority, which operates the subway, had said the closing was necessary to repair damage from Hurricane Sandy in 2012, when the tunnel between Manhattan and Brooklyn was inundated by floodwaters.
Under a new plan unveiled by Mr. Cuomo the work would be done on nights and weekends. He said not fulling closing the L train would be a “phenomenal benefit to the people of New York City.’’
It was not yet clear what alternatives the M.T.A. would choose. The authority, for example, could choose to do the work on nights and weekends.
For months, subway officials have been preparing for the closing and planning alternate routes for commuters to reach Manhattan, which have included a significant expansion of bus service and adding bike lanes. When the shutdown was announced in 2016, the news prompted panic in Brooklyn over what it meant for real estate and local businesses to be choked off from Manhattan.
Last month, Mr. Cuomo, who controls the subway, toured the L train tunnel with engineering experts to see if there was another way to undertake the repair work.
“If there’s a better way of doing it, they tell us there’s a better way of doing it,” Mr. Cuomo said at the time. “If there’s not a better way of doing it, they say that’s the best that it can be done.”
The transit agency initially said the shutdown would be 18 months and later shortened it to 15 months. Subway officials had considered two proposals — a shorter, full closing of the tunnel or a partial three-year shutdown that would have allowed some trains to continue running.
They chose the full closure in an effort to do it quickly and limit the inconvenience for riders.
The solution, developed by a team of engineers from Columbia and Cornell Universities over the last month, relies on a “racking system” to house the tunnel’s cables on the wall, instead of encasing them inside a separate structure, known as a bench wall.
Michael Horodniceanu, the authority’s former president of capital construction, said the new solution might only last 15 to 20 years while the earlier proposal, calling for a full rehabilitation, could last more than 80 years.
Mr. Byford, who has led the subway for a year and pledged to turn around terrible service, said the agency had considered a racking system for the L train project before his arrival, but there were concerns about “slinging the cables off what is a very old tunnel.” He said the panel of experts had found a way to make it feasible.
Mr. Byford said he had started a “due diligence exercise” to get answers to some of his “outstanding questions” about the new repair plan, like whether removing unstable parts of the bench wall could create silica dust that would be hazardous to riders.
In fact, in London, the subway has hung power and signal cables on its tunnel walls using brackets, shelves and other fixtures since the system was founded in 1863, often because there was no choice. Most of its tunnels are too narrow to accommodate bench walls. The cables, which are hung on the sides of walls and also overhead, run along parts of the deepest and most narrow tunnels, including the Northern, Central and Bakerloo lines.
Officials at Transport for London, the operator of the London Underground, said it was easier to repair and maintain the cables when they are not built in the walls. Although the cables can be vulnerable to leaks and track fires, officials said that it is not a major problem because the cables can easily be inspected and repaired.
Those experts were from the engineering schools at Columbia and Cornell universities. When they looked at the damage caused to those two tunnels by Hurricane Sandy, they concluded that there was a more efficient way to address the two problem areas than shutting the tunnels down.
One problem was the wiring, which is at the bottom of the tube and got soaked in sections. Instead of repairing it in place, they suggested running new wiring at the top of the tunnels. Problem solved.
The other was damage to the “bench walls,” the concrete paths running alongside the train. The prior plan had been to replace the entire bench wall. The profs suggested fixing only the problem areas, which are relatively small.
...In 2012, Superstorm Sandy infiltrated the Canarsie Tunnel, which carries the L train under the East River between Brooklyn and Manhattan. Seven million gallons of corrosive saltwater damaged the tube structure, the tracks and ties, and signal and other electrical equipment."Feedback" whether or not there's a "knothole in the paywall". Being a Times subscriber, I have no way of knowing.
The repairs needed on the tunnel are extensive, and the engineering plans to make it more resilient in future storms are complex and took considerable time to develop.
The solution identified by the engineers and consultants of the Metropolitan Transportation Authority, who have expertise with both subways and under-river tunnels, was designed to evaluate the integrity of the tunnel and produce a permanent fix. That project, involving shutting down the tunnel for 15 months, was supposed to begin in April