RULE 44. DESIGNATED STARTING AND RELIEVING POINTS. The Company will designate spot tracks in all yards where switch enginemen will commence and end shifts; such tracks to be at or near roundhouses or other points where engines are supplied or the convenience of the Company may require. When, upon reporting for duty, engineer is notified that the engine he is required to run is busy in another locality, he will report thereto as soon as possible and engineer relieved will be under pay until regular relief point is reached. The necessary register will be maintained at regular relief point.