The 169 escalators throughout New York City’s subway system are not known for running smoothly — each averaged 68 breakdowns or repair calls last year — and the Metropolitan Transportation Authority now says it has a partial solution.
Starting Monday, 35 recently installed escalators at four stations will start operating at variable speeds as part of a pilot program. Using infrared motion sensors, the escalators will slow to a crawl of just 15 feet per minute when no one is on them, compared with the normal full speed of 100 feet per minute. The escalators will gradually accelerate to the full speed, over a period of a few seconds, once a rider steps on them.
“Like humans, machines benefit from a little rest from time to time, and the escalators that provide service to subway customers are no exception,†said Paul J. Fleuranges, a spokesman for New York City Transit, the arm of the authority that runs the subways and buses.
By replacing old escalators with new ones that use a variable-frequency drive and numerous sensors, positioned near the escalators, officials hope to save on energy costs, and, just as importantly, reduce the wear and tear on the many mechanical parts in the heavily used machines.
“It’s not an idea we invented,†Thomas Kenny, principal mechanical engineer in the department of capital program management at New York City Transit, said in a phone interview. “We call it sleep mode. Others call it intermittent operation. It’s been used widely across the world, particularly in Europe and Asia.†Airports in Canada, Germany and Israel also use variable-speed escalators, officials said.
Variable-speed escalators are rarely used in the United States, and the American Society of Mechanical Engineers, which sets code standards for escalators, hasn’t approved the devices yet. So New York City Transit sought and obtained permission from the code enforcement division at the New York State Department of State to install the escalators, and also subjected the escalators to rigorous tests in its internal system safety division, Mr. Kenny said.
The 35 escalators that are part of the experiment include 12 escalators at the 34th Street-Herald Square station on the B, D, F, V, N, R, Q and W lines in Manhattan; 8 escalators (4 of which have been installed) at the Roosevelt Island station on the F line; 5 escalators (2 of which have been installed) at the Jamaica-Van Wyck Boulevard station on the E line in Queens; and 10 escalators (6 of which have been installed) at the Parsons/Archer terminus of the E line in Queens.
By not running the escalators at a high constant speed, the authority estimates it will save at least $1,800 per escalator each year.
“These escalators are a very visible example of our commitment to contributing to a greener, more sustainable environment,†said Howard H. Roberts Jr., president of New York City Transit. “While at rest, these green escalators consume less energy, and are therefore more cost effective.â€
The officials also hope that the reduced wear and tear could extend the useful life of certain escalator components from 11 to 33 percent.
To explain how the new escalators work, officials are placing posters and brochures at the four subway stations.
Assuming the escalators work as intended, the goal is to switch on the variable-mode option at escalators in several more stations in the upcoming months, including the Bleecker Street station on the No. 6 line and the South Ferry terminus on the No. 1 line, both in Manhattan.
The 169 escalators are never all replaced at once, and the life cycle of an escalator can be as long as 35 years, so it will take years before all the escalators in the system operate at variable speeds, officials said.
