Page:Popular Science Monthly Volume 88.djvu/273

 Popular Science Monthly

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��New York Trains That Play Leap Frog

AVERY interesting traffic situation occurs on the long and attenuated Manhattan Island, which makes only one express track necessary. In the morning, New Yorkers travel southward to the

��they are known technically, the local sta- tions are situated.

The reason for the leapfrogging is ob- vious. There are three tracks in service already on the elevated line, but the third track could not be used for express serv- ice unless the trains crossed over and on

���Passengers riding on the express trains on

the new " L" tracks will be reminded of

the "roller coasters" at Coney Island

down town business sections, and in the evening return northward to their homes. In order to relieve the swelling traffic on the elevated lines in New York city, an ingenious method of track-laying has been resorted to. A horizontal view of the completed structure would bear a strange resemblance to the roller coaster railroads so much in evidence in nearly all of America's amusement parks. Near- ing a station, the express trains for which the new track is being designed, rise swiftly on an incline, so that they play at a modified, mechanical game of leapfrog. Under the raised tracks, or "humps," as

��At each express station, the new tracks

rise above the level used by the local

trains

the local tracks to take on and discharge passengers. This would involve delay and a serious possibility of accident, due to the failure of engineers to obey sig- nals.

The stations selected for the express stops are either reinforced or renewed, and the middle track is raised abov.t

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