No person, except the man giving the signal, shall jump on a car, cage or gun-boat after the signal to start has been given, and if any person shall enter a car, cage or gun-boat in excess of the lawful number the headman or footman shall notify him of the fact and request him to get off, which request must be immediately complied with. Any violation of this rule must be reported promptly to the mine foreman.
52 P.S. § 70-722