RULE 95. NEW TIME CARD . When a new time-table takes effect engineers will be accorded preference for main line passenger service, branch line passenger service emanating at or running into the home terminal of the district concerned, and chain-gang freight service where seniority rights extend over two or more districts. When a supplement to a new time-table is issued, it will be regarded as a new time-table on the district affected, except where supplements are issued affecting tenant line trains exclusively. Engineers must exercise their choice of runs within 4 days.