Automatic Block Signal System (ABS) Rules
Block signals govern the use of the blocks. They do not dispense with the use or observance of other signals whenever and wherever required and do not authorize main track occupancy.
507. Withdrawal of Signals
When signals in ABS are withdrawn from service, movements will be governed by instructions from the RTC or special instructions.
509. Instructions to Pass Signal Indicating Stop
(a) A movement must have instructions from the RTC to pass a block signal indicating Stop. If stopped at the signal indicating Stop, and no conflicting movement is evident, a crew member must immediately communicate with the RTC.
EXCEPTION: Instructions are not required when a movement is required to re-enter a block occupied by a portion of their movement, however, the movement must proceed at REDUCED speed.
(b) When able to, the RTC will inform the crew member in writing:
“There is no conflicting movement” After complying with Rule 513 where applicable, the movement need not stop at the signal but must positively identify the signal by number and the movement may proceed at RESTRICTED speed to the next signal or Block End sign.
(c) When unable to obtain the information that there is no conflicting movement in the block, and no conflicting movement is evident, the movement may, after complying with Rule 513 where applicable, move forward and must stop where its leading wheels are 100 feet past the Stop signal. After waiting 10 minutes and if there is still no evidence of a conflicting movement, the movement may proceed at RESTRICTED speed to the next signal or Block End sign.
513. Entering Main Track
(a) Before entering or fouling a main track and no movement is observed approaching on the main track, a crew member must reverse the switch and wait five minutes, unless a greater period is specified in special instructions before allowing the movement to move foul of the main track. The crew member must remain at the switch until the movement has entered the track. The switch must be quickly restored to its normal position should an approaching movement on the main track become evident.
When entry is to be made through a crossover, the switch in the track on which the movement is standing is the only crossover switch to be reversed for the required waiting period.
EXCEPTION: The required waiting period need not be observed within cautionary limits or when:
an opposing movement has passed the switch and is still occupying the block;
the crew entering the main track is in possession of a clearance to work; or
the crew is relieved in writing by the RTC.
Before relieving a crew, the RTC must ensure that there are no movements operating in the block that will approach the switch. The switch must be opened within 5 minutes after receiving permission from the RTC.
(b) A movement entering a block between signals, must move at RESTRICTED speed to the next signal, unless or until the track is seen to be clear to the next signal and the indication of such signal permits movement at other than RESTRICTED speed.
515. Delayed in the Block
When a movement, which has entered a block on signal indication permitting operation at other than RESTRICTED speed, is stopped or otherwise delayed in the block, it must move at REDUCED speed to the next signal:
(i) unless there are no switches between such movement and the next signal; or
(ii) until the track is seen to be clear to the next signal.
The movement must approach the next signal prepared to stop and be governed by the indication displayed.