No railroad company, or any employee, agent or servant thereof, shall make or cause to be made what is known as a flying switch within the City, or cause or permit any car or cars or other rolling stock to run or move upon any railroad tracks when such car or cars or other rolling stock are detached from the locomotive in charge or its crew, unless the railroad company has upon such car, cars or other rolling stock, and in control of the brakes thereof, some employee properly qualified to control and who is controlling the movements of such car, cars or other rolling stock.
(1958 Code § 21.4)