It shall be the duty of all persons operating switch trains or switch engines over, on or across public streets and highways within the city to keep a switchman stationed on the end of such switch train or switch engine nearest the crossing to be crossed in sight of the engineer or in sight of some member of the switching crew. From the time such train or engine is within 100 feet of such crossing it shall be the duty of the switchman to keep a lookout at the crossing until the train crosses such street or public highway, and warn any and all persons who may be on or approaching such crossing of the approach of such train or engine and give signals to the engineer or other members of the switching crew of any person who may be on or about to go upon such crossing in front of such train or engine.
(1964 Code, § 31-29)