Electrical equipment and other technology used to operate New York City’s subway system may be ruined after salt water reached sensitive infrastructure during Hurricane Sandy.

New York’s Metropolitan Transportation Authority (MTA) this week will be inspecting about 600 miles of track and extensive electrical systems to discover the extent of the massive damage which forced the shutdown of the mass transit network.

It is known that seven subway tunnels under New York’s East River were flooded. Lower Manhattan’s subway infrastructure also saw “extremely severe” water damage from the hurricane, and the South Ferry station was filled “floor to ceiling” with water, according to news reports.

It may take three weeks to get the subway system back to a 90 percent operational level, according to a report from Bloomberg Businessweek based on an earlier study. The damage estimates to the region’s transportation infrastructure may be in the tens of billions of dollars.

“No subway system is designed for a flood of this magnitude,” Nasri Munfah, chairman of tunnel services at HNTB Corp., a consulting firm, told Bloomberg (News - Alert) Businessweek. He said the subway system can be ruined by salt water.

“It’s like dropping your computer into a bucket of salt water,” he added.

Similarly, MTA Chairman Joseph Lhota told WNYC, “Water and electricity never mix properly, but when you add salt to it, once the water is gone, the salt leaves a film,” the Financial Times quoted the statement.

“The way electronics work on the subway system is two pieces of metal running together conducting electricity. And if there’s anything in between those two pieces of metal – like film left over from salt – that needs to be cleaned off because the connections need to be clear,” he added.

The MTA will have to clean and test thousands of connections in signal systems.

“The New York City subway system is 108 years old, but it has never faced a disaster as devastating as what we experienced last night,” Lhota said in an MTA statement. “Hurricane Sandy wreaked havoc on our entire transportation system, in every borough and county of the region. It has brought down trees, ripped out power and inundated tunnels, rail yards and bus depots.”

Similarly, Radley Horton, an associate research scientist at Columbia University’s Center for Climate Systems Research, told NBC News that “saltwater and electricity don’t mix. Even after that water is removed, it’s going to take some time to replace the electrical equipment, test signals, that sort of thing.”

Switches, lights, turnstiles and the third rail may have been damaged by salt water, news reports said.

Also, Mortimer Downey, a former MTA executive director and now a board member of the Washington, D.C., Metropolitan Area Transit Authority, told Bloomberg Businessweek that testing is needed because “what you don’t want is a short circuit that causes the system to fail.”

In addition, Kathy Waters, vice president for member services at the American Public Transportation Association, predicts it may be hard to find spare parts for the subway system.

“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 told Bloomberg Businessweek.

Meanwhile, the MTA was defensive about criticism, saying it took every precaution the agency “possibly could” have before the storm hit.

Sandbags were placed at subway entrances and vents were covered as well. The MTA cut power to tracks before the flood, The Associated Press reported.

Joseph Schofer, a professor of civil and environmental engineering and the director of Infrastructure Technology Institute at Northwestern University, told Bloomberg Businessweek, “They protected a lot of the vulnerable infrastructure.”

“They shrink-wrapped fare machines, and they also pulled equipment out of low-lying areas, particularly the tunnels,” he added.

Sandbags and plywood attempt to repel flooding from Hurricane Sandy at South Ferry Station. Image via Shutterstock

In addition, New Jersey Transit’s rail operations center saw its computer system damaged from the storm. The center was described as “the central nervous system of the railroad” and it is now “engulfed in water.” Among those items damaged are “backup power supply systems, the emergency generator, and the computer system that controls the movement of trains and power supply,” according to an agency statement.

In addition, the storm caused a Long Island Railroad tunnel under the East River to flood. Also flooded were a PATH train tunnel under the Hudson River, and the Brooklyn-Battery tunnel, according to the Financial Times (News - Alert).

Overhead power lines for Metro-North trains were also damaged in several areas, The AP said.

In a related matter, when it comes to utilities, an explosion at a New York City substation left hundreds of thousands of New York customers in the dark and equipment damaged from the storm, according to a report from TMCnet. The Consolidated Edison substation is located on 13th Street in Manhattan.

Nationally, the hurricane may lead to a review of the vulnerability of infrastructure to weather-related damage.