(a) The speed of mantrips shall be governed by the mine foreman and mantrips shall be operated at safe speeds consistent with the condition of roads and type of equipment used. Each mantrip shall be under the charge of a competent person designated by the mine foreman¹ or his assistant. It shall be operated independently of any loaded trip of mine cars, but may include tools and small machine parts.

(b) Cars on the mantrip shall not be overloaded, and sufficient cars in good mechanical condition shall be provided. “Drop-bottom” cars shall not be used for mantrips unless they are provided with a secure supplementary locking device. No person shall ride under the trolley wire unless suitable covered man cars are used. Men shall not load or unload before the cars in which they are to ride, or are riding in, come to a full stop. Men shall proceed in an orderly manner to and from mantrips.

(c) When belts are used for transporting men, a minimum overhead clearance of eighteen inches shall be maintained between the belt and the roof or crossbars, projecting equipment, cap pieces, overhead cables, wiring, and other objects. Where the height of the coal seam permits, the overhead clearance shall not be less than twenty-four inches. The belt speed shall not exceed two hundred fifty feet per minute where the minimum overhead clearance is eighteen inches, or three hundred feet per minute where the minimum overhead clearance is twenty-four inches. Men shall ride not less than six feet apart. Where men are transported, control lines shall be installed the full length of the belt with control switches placed along the belt line at intervals not exceeding two hundred feet unless equivalent or safer protection is provided. Emergency switches shall be wired in such a manner so that when the belt is stopped it cannot be started by any other switch except the one that was de-energized.

(d) An assistant mine foreman or some other person designated by the mine foreman shall supervise the loading and unloading of belts and mantrips. Adequate clearance and proper illumination shall be provided where men board or leave conveyor belts.

(e) Adequate precautions shall be taken so that moving trips and standing cars are subject to proper control by derailing or braking devices.

(f) It shall be unlawful to operate any conveyor belt in any anthracite coal mine unless such conveyor belt is efficiently insulated by flame resistant material: Provided, however, That an operator who, on April 4, 1956, has in use or on hand within the State of Pennsylvania, a conveyor belt which is not fire resistant may use such conveyor belt in the same or in any other mine of the same operator until replacement is necessary.