Grand Scales General Code of Operating Rules – First Edition – January 1, 2007
Red Tail light 3.17 A red marker lamp or pair of lamps of the prescribed type will be displayed at the rear of every train at night to indicate the rear of the train.
Blue Light 3.18 A blue signal displayed at one or both ends of an engine, car, or train, indicates that workmen are under or about it; when thus protected it must not be coupled to or moved. Other equipment must not be placed on the same track as to intercept the view of the blue signals, without first notifying the workmen who placed the blue signal. Only the workmen who placed the blue signal may remove it.
Blue Track Lock 3.19 In addition to blue lights or blue flags, a special lock must be maintained on the lead switch to the track displaying the blue signal, the key kept by the workmen who placed the blue flag.
Blow the Whistle 3.20 The whistle must be sounded at all places where required by rule or by law.
No Unnecessary Bell and Whistle 3.21 The unnecessary use of either the whistle or the bell is prohibited.
Callout the Signal 3.22 All members of train and engine crews must, when practicable, communicate to each other by its name the indication of all signals affecting the movement of their train.