[Scan-DC] Metro Train Control

[Todd Sniffin]

Metro trains do have anti-climbers on most, but not all of the cars.  They
are nothing more than a ridged horizontal plate above the coupling.  As
noted in a prior message, they most likely would not have worked in this
case-the speed was too significant.

Metro uses automatic train control systems, however they have been only
semi-functional due to maintenance issues and incompatible technology
between old cars, new cars and software.  The automatic train control system
(ATC) is made up of three subsystems-automatic train protection, automatic
train operation, and automatic train supervision.  ATP provides safety
functions such as anti-rollback (this failed in the last metro incident),
braking, marker identifcation/reception, and overspeed control.  ATO
regulates speed and allows the train to automatically stop at the proper
space in the station and automatically open the doors.  ATS transmits train
information (ID, length, door status, speed limit data, etc...) between
wayside areas and the onboard train systems.

When operators go in the "manual mode" that means ATC is not being utilized
and speed, braking, door controls, and station stops are all under the
operators control.

TS