2025/2026. 100%. 75Q&A.
Block
A length of track of defined limits, the use of which is governed by block signals, block limit signals,
automatic speed control or any combination thereof
Absolute Block
A block established between block stations, block limit stations, interlockings or any combination
thereof which must not be occupied by more than one train except as provided by the rules.
Automatic Block Signal Systems
A block signal system wherein the use of each block is governed by an automatic block signal, the
cab signal indicator or both
Block Signal System
A series of consecutive blocks.
Manual Block Signal System
A block signal system wherein the use of each block is governed by block signals controlled manually,
by block-limit signals or both, upon information received by telephone, radio or other means of
communication.
Automatic Speed Control System (ASC)
A system so arranged that its operation will automatically result in the following: A full service
application of the train brakes if, while operating under a speed restriction, the speed of the train
exceeds the predetermined rate. The application will continue until the train is either brought to a
stop or, under the control of the engineer, its speed is reduced to the predetermined rate.
Speed Controlled Train
A train equipped with the following speed control apparatus, a cab signal indicator, sealed
application valve or switch, audible warning device and acknowledging switch, in operative condition
for the direction in which it is to move.
Engine (ENG)
A unit propelled by any form of energy or a combination of units operated from a single control,
used in road or yard service.
Multiple Unit Equipment
Equipment capable of being propelled by electrical energy through the use of third rail contact
shoes.
Track Car (TC)
, A roadway maintenance machine, not classified as an engine, which is operated on track for
inspection or maintenance. It may not shunt track circuits or operate signals and will be governed by
rules and special instructions for trains other than passenger trains.
Interlocking (INT)
An arrangement of signals and signal appliances so interconnected that their movements must
succeed each other in proper sequence and for which interlocking rules are in effect.
Interlocking Limits
The tracks between the extreme opposing home signals of an interlocking.
Pilot
An employee assigned to a train or track car when the engineer, conductor or track car driver is not
qualified on the physical characteristics or rules of the railroad or portion of the railroad over which
the movement is to be made.
Aspect
The appearance of a fixed signal which conveys an indication as viewed from the direction of an
approaching train; the appearance of a cab signal indicator as viewed in the engine control
compartment.
Block-Limit Signal
A fixed signal indicating the limit of the block, the use of which is governed by manual block signal
system rules.
Block Signal
A fixed signal or a hand signal in the absence of a fixed signal, at the entrance to a block that governs
trains using that block.
Cab Signal Indicator
A signal indicator located in the engine control compartment displaying the maximum speed for the
movement of the train. It will be used in conjunction with interlocking signals and either in
conjunction with or in lieu of block signals.
Distant Signal
A fixed signal used to govern the approach to a home signal.
Fixed Signal
A signal of a fixed location indicating a condition which affects the movement of a train.
Home Signal
A fixed signal that displays stop as its most restrictive aspect and governs the entrance to a route or
block.
Indication
The information conveyed by the aspect of a signal.