S-242. On subdivisions specifed by special instructions, the authority of trains to occupy a designated subdivision will be governed by train register.
Permission of the train dispatcher must be obtained before registering on the subdivision and all trains entering on or departing from such subdivision must be registered.
The Conductor will examine the register and properly record his train and inform the Engineer accordingly. The Engineer will not enter on or depart from the subdivision until so informed by the Conductor.
The first train entering on the subdivision is authorized to occupy the subdivision without protecting against other trains.
When the train register indicates the subdivision is occupied by another train, another train must not occupy the subdivision without protecting against such train, except when written flagging instructions are arranged between the Conductors of the trains concerned.
When written flagging arrangements are made, the Conductors will use every precaution to gaurd against error, and will give each Engineer a copy.