RULE 93. CALLING. (a) At district terminals engineers in road service residing within one and one-half miles from crew dispatcher's office will be called, as near as practicable, one hour before time required to report for duty. Where engineers provide themselves with telephone service at their own expense they shall be called by telephone and the distance within which they shall be called shall not be limited.  

(b) In assigned road service where employees report for duty without being notified or called and it is desired on any day to defer the reporting time, notice shall be given not less than the usual advance calling time for reporting for duty at each terminal and in accordance with usual calling practices at such terminal. The employee shall be notified at such time when he is to report and only one such deferment may be made. In such cases the time of the trip or tour of duty shell begin at the time the employee is required in accordance with said notice of change to report for duty. If not so notified, the reporting time shall be as provided in the assignment.

  NOTE.   Engineers requiring more than one (1) hour call will notify the crew dispatcher in writing and will be called as near as practicable at the time desired.