Main Track - Correct Answer A track extending through yards and between stations that must
not be occupied without authority or protection.
Station - Correct Answer A place designated by name in the timetable station column.
Single Track - Correct Answer A main track where trains are operated in both directions.
Train - Correct Answer One or more engines coupled, with or without cars, displaying a marker,
and authorized to operate on a main track. A term that when used in connection with speed
restrictions, flag protection, and the observance of all signals and signal rules also applies to
engines.
Yard Limits - Correct Answer A portion of *main track* designated by yard limit signs and
timetable special instructions or a track bulletin. Within Yard Limits, trains or engines are
authorized to use the main track not protecting against other trains or engines. *You can have
Yard Limits without a yard.* (Rule 6.13)
Yard - Correct Answer A system of tracks, other than main tracks and sidings, used for making
up trains, storing cars, and other purposes.
Siding - Correct Answer A track connected to the main track and used for meeting or passing
trains. Location of sidings are shown in the timetable.
Spur Track - Correct Answer A track connected to another track at only one end, also referred
to as a stub track.
Track Bulletin - Correct Answer A notice of conditions affecting train movement. It may also
authorize movement against the current of traffic where Rule 9.14
, (Movement with the Current of Traffic) is in effect.
Track Warrant Control (TWC) - Correct Answer A method to authorize train movements or
protect men or machines on a main track within specified limits in a territory designated by the
timetable.
Block - Correct Answer A length of track:
-- Between consecutive block signals
-- Between a block signal and the end of block system limits
or
In ATC limits, the use of which is governed by cab signals and/or block signals.
Fixed Signal - Correct Answer A signal that is fixed to a location permanently and that indicates
a condition affecting train movement.
Block Signal - Correct Answer A fixed signal at the entrance of a block that governs trains
entering and using that block.
Block System - Correct Answer A block or series of consecutive blocks within ABS, ACS, CTC, or
interlocking limits.
Automatic Block Signal System (ABS) - Correct Answer A series of consecutive blocks governed
by block signals, cab signals, or both. The signals are activated by a train or by certain
conditions that affect the block use.
Signal Aspect - Correct Answer The *appearance* of a fixed or cab signal.
Signal Indication - Correct Answer The *action* required by the signal aspect.