RULE 51. RIGHTS. (a) After a yard engineer has been off for four days, other assigned yard engineers may take the run, if they so desire, in preference to extra men.

NOTE: Vacancies caused by the absence of yard engineers on vacation at Kansas City, Council Bluffs, Omaha and Grand Island will be filled daily from the extra board by engineers standing first-out at calling time.

(b) Engineers working in yard service must have had a minimum of one year's actual experience in road freight service in order to exercise seniority rights in passenger service. After engineers who hold road rights have been in-yard service for one year or more, they will be required to perform main line freight service for 90 days before they can exercise seniority rights in passenger service. This requirement also -applies to engineers who have had one year or more actual service in road freight service prior to entering yard service.

(e) Road engineers who have been in yard service one year or more and who have not made a road trip in that year will be required to make one trip in main line freight service, without compensation, before they can exercise seniority in freight service.