Big job ahead restoring NYC subway
Wednesday , October 31, 2012 - 9:41 AM
NEW YORK - If you laid the New York City subway system in a line, it would stretch from New York to Detroit.
Now imagine inspecting every inch of that track.
That’s the job ahead for Metropolitan Transit Administration officials, who must examine 600 miles of track and the electrical systems with it before they can fully reopen the largest U.S. transit system, which took a direct hit by Hurricane Sandy.
Seven subway tunnels under New York’s East River flooded, MTA officials said. Pumping them out could take days, and a 2011 state study said it could take three weeks after hurricane- driven flooding to get back to 90 percent of normal operations. That study forecast damages of $50 billion to $55 billion to transportation infrastructure including the subways.
"No subway system is designed for a flood of this magnitude," said Nasri Munfah, chairman of tunnel services at HNTB, a Kansas City, Mo.-based infrastructure construction, design and consulting firm. "I don’t think it’s going to be a matter of a day or two. It’s a big job."
Chairman Joe Lhota of the MTA, which carries an average of 8.7 million riders on weekdays, called the storm the worst disaster in the subway’s 108-year history. Sandy, which made landfall in New Jersey and swept north to New York City, was the largest tropical storm measured in the Atlantic.
New Jersey Transit’s rail operations center was engulfed in water, damaging the computer system that controls the movement of trains and power supply, the agency said in a statement Tuesday.
A subway system has an electrical system that runs equipment, pumps, lights and communications, one that runs switches and signals and a third that powers the electrified third rail for train propulsion, Munfah said. All can be ruined by salt.
"It’s like dropping your computer into a bucket of salt water," he said.
MTA officials Tuesday said the extent of electrical damage can’t be assessed until the water is drained.
Thousands of connections in signal systems will need to be cleaned and tested before trains can run again, said Mortimer Downey, a former MTA executive director and current board member of the Washington Metropolitan Area Transit Authority.
"It’s an enormous amount of wiring and an enormous amount of connections that go to what’s called relay rooms," Downey said. "They’ve got to turn the system on, and if it seems to be working I think they’ve got to go to every component and check it and get rid of all the salt. What you don’t want is a short circuit that causes the system to fail."
Such a failure caused the deadliest crash in the history of Washington’s Metro system in 2009, he said.
Finding enough replacement parts will be another challenge that could delay repairs, said Kathy Waters, vice president for member services at the American Public Transportation Association.
"The New York system, although there are some components that have been upgraded over the years, has a lot of antique components where the vendor has been out of business for 50 years," Waters said in an interview.
"To some extent, they will have inventory," she said. "But depending on the extent of damage, you don’t keep things on the shelf to have a replacement for every piece should it all go down at once."
A 2011 study funded by New York state concluded it would take 21 days to restore the subway system to 90 percent of its full operations after flooding caused by a severe hurricane.
It estimated it would take a week to pump water out of tunnels, assuming officials could get 100 portable pumps. The subway had only three mobile train pumps for the entire system, the report said.
The study, which assumed damage levels from a once-in-100- years storm, estimated 1 billion gallons of water would have to be pumped out of the subway system.
"The essence of that report unfortunately came true," Klaus Jacob, the Columbia University scientist who co-wrote the study, said in an interview.
Subways’ pump rooms are designed to handle runoff from typical storms, not floods, Munfah said. The pumps run on electricity, with diesel generators as a limited backup. The 14- foot storm surge was much higher than any planned flood level, so the systems couldn’t do much to keep up.
The city decided before the storm hit to end train and bus service, moving equipment to safety and encouraging customers to stay home.
Moving trains out of the tunnels and turning off power to the electrified third rails prevented the damage from being worse, Munfah said.
"We took every precaution we possibly could," said Deirdre Parker, a spokeswoman for the MTA, citing the use of sandbags at subway entrances and the agency covering vents. "It was just a record-setting storm surge. There was really nothing else we could have done."
New York has handled the storm preparations and aftermath as well as it could, said Joseph Schofer, a professor of civil and environmental engineering and the director of Infrastructure Technology Institute at Northwestern University in Evanston, Illinois.
"As best I can tell from what they’ve done in the past, they protected a lot of the vulnerable infrastructure," said Schofer, who directed a case study last year of how the MTA responded to Hurricane Irene in 2011. "They shrink-wrapped fare machines, and they also pulled equipment out of low-lying areas, particularly the tunnels. Electrical equipment is particularly vulnerable."
An inundation like this could have been predicted given the depth of New York’s subway tunnels compared with cities with more modern underground tunnels, Downey said in an interview.
Lines under the river are low points in the system, leading water to collect there, he said.
"Our transit system wasn’t designed for this kind of surge of water pouring into lower Manhattan," former New York Lt. Gov. Governor Richard Ravitch, a co-chairman of the State Budget Crisis Task Force, said Tuesday in an interview on Bloomberg Television. "Nobody ever dreamed of this. It’s not something that can be easily changed, either."
— With assistance from Brian Chappata, Esme E. Deprez and Henry Goldman in New York, and Jeff Plungis in Washington.
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