a. Cab Signal does not conform to fixed signals: More restrictive signal governs
The cab signal should conform to each fixed signal within three seconds after a train enters a block. If the cab signal and fixed signal do not conform, the more restrictive signal indication will govern movement through the block. The engineer must notify the Dispatcher or Operator as soon as possible without delaying the train, giving location and track on which nonconformity occurred.
b. Can Signal conforms to Fixed Signal: Fixed Signal governs
If the Cab Signal conforms to the fixed signal upon entering the block, the fixed signal will govern.
It is important that the engineer know what speed is authorized when he enters the block in Cab Signal territory. Rule 552 deals with the conformity between the cab signal and wayside signal and what to do if they don't conform. When entering the block and the wayside and cab signal indications are the same, then the engineer will operate by the wayside signal. If they don't conform, the safest course would be to operate using the more restrictive of the two signal indications. The rule requires that the safe course be taken.
Rule Review:
Rule 552, Conformity between cab signals and fixed signals:
Being interconnected with the fixed signal system, the cab signal must conform with the fixed signal system:
1. Within ten (10) seconds after the train
enters the block.
2. Within five (5) seconds after the train
enters the block.
3. Within three (3) seconds after the
train enters the block.
4. Within three (3) seconds prior to the
train entering the block.
When cab signal and fixed signal do not conform:
1. The more restrictive signal indication
will govern and the Dispatcher notified as soon as possible.
2. The cab signal will govern and the
Dispatcher notified when the train arrives at it's destination.
3. The train crew must be notified.
4. The engineer must panic.
When the cab signal changes to Restricting between fixed signals:
1. The engineer must dump the air.
2. A report must be made on the prescribed
form.
3. The engineer must take action at once
to reduce to restricted speed
4. The engineer may disregard if the fixed
signal was more favorable.
If an interlocking signal requires Medium or Limited Speed and the cab signal changes to a more favorable aspect:
1. Speed may be increased immediately.
2. Speed may be increased after the head
end passes the next fixed signal.
3. Speed may be increased after the rear
of the train passes the next fixed signal.
4. Speed must not be increased until the
train has run its length.
If a cab signal changes from Restricting to a more favorable aspect:
1. Speed may be increased immediately.
2. Speed may be increased after the head
end passes the next fixed signal.
3. Speed may be increased after the rear
of the train passes the next fixed signal.
4. Speed must not be increased until the
train has run it's length or 500 whichever is greater.
If the cab signal changes from clear to approach medium between fixed signals:
1. The engineer must dump the train.
2. The train must immediately begin reduction
to limited speed.
3. The train crew must be informed so
they can announce the impending collision to the passengers.
4. The Dispatcher must be immediately
informed so that he can call the trouble desk.