Winter Storm Hercules: How The MTA Keeps NYC Subway And Commuter Tracks Free Of Snow And Ice

How D

 @rpalmerscience on January 03 2014 11:32 AM
snowjet
The SnowJet, a big snow blower souped up with a jet engine, can vaporize snow right off the tracks. Flickr/MTA photos

New York City’s hardly getting the worst of this latest winter storm, but is still contending with more than the expected 6 inches of powder in certain areas. But thankfully for commuters, the Metropolitan Transit Authority has a stable full of snow-fighting equipment to cut through the blizzard’s wrath.

The MTA’s snow-busting equipment includes snow throwers, which look like demented mechanical escapees from a car wash. It’s a special diesel-powered train with a 6-foot cylindrical brush that scoops snow off subway tracks and blows it out through a chute. The MTA’s snow thrower can chuck chunks of snow up to 200 feet away and remove about 3,000 tons of powder every hour.

“This is similar to a household snow blower, just a lot bigger,” the MTA says.

The agency also keeps five jet engine-powered blowers that blast accumulated snow off the tracks. The New York Times likened them to a hybrid between a train’s caboose and Sesame Street’s Snuffleupagas. And these beasts have some hot breath. The blowers travel on the rails with diesel engines, but use a high-efficiency Rolls Royce Viper aircraft turbine engine to vaporize snow with exhaust that gets up to 600 degrees Fahrenheit.

"If the jets do the job right, all you see is steam coming off the steel," Peter Hall, foreman of the MTA’s Maintenance of Way equipment shop in North White Plains, N.Y., said in 2011. "They produce 2,500 pounds of thrust, which makes them very good at getting under heavy, wet slush, ice and crusty snow."

The jet blowers are only used on commuter lines like the Metro-North and the Long Island Railroad, since they generate a lot of noise (imagine the noise complaints that would arise if a jet engine was running in the subway tunnels under Union Square).

For subway tracks, the MTA rolls out special de-icer cars that have special ice-scraper shoes and devices to spit out de-icing fluid. It’s especially important to keep the third rail clear. A buildup of ice and snow would keep the subway train from properly making contact with the third rail, meaning that it could not draw electric power and would stop.

Most homeowners won’t be able to turn to jet engine-powered assistance in fighting snow. Aside from shovels and elbow grease, one ally in a blizzard is road salt, whether tossed on the sidewalk by hand or spewed from trucks by the Department of Sanitation.

Salt makes it harder for ice to form by lowering the freezing point of water. How does it do this? By basically throwing a molecular wrench in the works.

"Any impurity disrupts water molecules' ability to find each other and to organize in the right way," Joel Thornton, professor of atmospheric sciences at University of Washington in Seattle, explained to PBS. "When you add salt to the road, what you're doing is you're adding impurities to the water so you disrupt the water's ability to form ice."

But road salt can rust cars and kill plants, which leaves many cities and states looking for more environmentally friendly alternatives. Some municipalities, like Toronto, have tried a mixture of beet juice and brine. While slightly more expensive, beet juice is less harsh on the environment, and is actually more effective at lower temperatures than brine alone.

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