RULE 27. (a) Engineers assigned to helper service shall be called first-in and first-out for initial service each 8 hour helper day.

(b) Assigned helper engineer, who is available and ready for service the entire month, shall be guaranteed 3300 miles per month.

(c) If an assigned man lays off of his own accord or is relieved during the month he shall receive what he earned but not less than his proportion of the monthly guarantee for the number of days worked or held.

(d) Extra engineer relieving a regular man shall be paid not less than his proportion of the monthly guarantee for the number of days worked or held, except that in the operation of males regulating mileage, the guarantee shall not apply to the relieving man or men.

(e) In case traffic is interrupted to the extent of 48 hours or more at one time in any calendar month from any cause over which the Company has no control, the guarantee will not apply during the period of such interruption.

(f) When crews are released and called on duty again before expiration of 8 hours, time will be computed as continuous. If called on duty after 100 miles have been run, or after expiration of 8 hours from starting time of initial trip, a new day will begin.

(h) Road engineers will not be required to do helping service except in emergencies, in which case they will be paid in accordance with Rule 71.