• what are these two things between the running rails

  • Discussion related to DC area passenger rail services from Northern Virginia to Baltimore, MD. Includes Light Rail and Baltimore Subway.
Discussion related to DC area passenger rail services from Northern Virginia to Baltimore, MD. Includes Light Rail and Baltimore Subway.

Moderators: mtuandrew, therock, Robert Paniagua

  by Sand Box John
 
"justalurker66"
It seems that it would help to think of them as location markers (to find the center of a platform) and not "stop here" signs.


They convey more information to the trains then just distance. They also convey information about the grade profile on the approach to the station. The level of brake application needed to stop a train ascending 2 percent grade into a station is different then descending a 1/2 percent grade into a station.