You Mean Besides The Fact That You’ll Make Me Late To Work And I’ve Already Gotten To Work Late Like Every Day This Week?

“why we shouldnt pull emrgency cord on subway trains” (1/26/08)

But if you really must know:

The emergency brakes are released when a passenger pulls the dangling cord at either end of the subway car, or when the steel lever attached to the undercarriage of the lead car — called a trip cock — strikes an object lying on the tracks or track bed. Each time this occurs, a train operator must leave the cabin, inspect the tracks under each car and clear any obstacles before beginning the 10-minute process of repressurizing the brakes, according to Jared Lebow, a Transit Authority spokesman. It can take a while.

In most emergencies — when a passenger is ill or caught in the doors — the brake cord should be pulled only to prevent the train from leaving a station, Mr. Lebow said. Passengers shouldn’t pull the cord while the train is in a tunnel, he said, unless a passenger falls onto the tracks.

. . .

The emergency brakes are pressurized to 110 pounds per square inch. Although they won’t stop the train on a dime, they can bring a 400-ton string of cars moving 30 miles an hour to a halt in about 250 feet.