(1) All apparatus must be designed throughout, with not less than the following factors of safety, under static full rated load stresses, based on ultimate strength of the material used:

(2) A notice must be placed on every crane and hoist showing the maximum allowable load in pounds or tons. This notice must be placed in such a manner as to be clearly legible from the floor.

(3) Cranes must be of what is known as "all steel construction." No cast iron will be used in parts subject to tension except in drums, trolley sides, bearings, brackets and brake shoes.

(4) The construction of cranes must be such that all parts may be safely lubricated and inspected when cranes are not in operation.

(5) Bolts subject to stress must be of the through type and all bolts must be equipped with approved protection so that the bolt will not work loose or nuts work off.

(6) Outside crane cages must be enclosed. There must be windows on three sides of the cage and windows in the front, and the side opposite the door must be the full width of the cage.

(7) Where a tool box or receptacle is used for the storing of oil cans, tools, etc., it must be permanently secured in the cage or on the foot-walk of outside cranes and on the foot-walk of inside cranes. Tool boxes of hot metal cranes must be constructed of metal.

(8) All gears on cranes must be provided with standard guards.

(9) Keys projecting from revolving shafts must be guarded.

(10) A braking apparatus must be provided on every type of crane and must be so designed and installed as to be capable of effectually braking a weight of at least one and one-half times the full rated load.