SAFETY PROVISIONS BEYER. 221 



Is being obtained, and in order to insure proper attention to these 

 matters by crane builders, standard safety specifications have been 

 prepared for use in ordering new equipment for the American Steel 

 & Wire Co. These specifications provide for a footwalk on the side 

 of the crane bridge, with a toe board along the edge of this walk; 

 exposed gears are to be covered and overhung gears eliminated. 

 (Examples of these conditions are shown in pi. 4, figs. 1, 2) ; limit 

 switches are required to prevent a load being lifted too high and 

 breaking away from the drum ; a safety switch is to be placed on the 

 upper part of the bridge so that a workman can throw out this switch 

 and prevent anyone starting the crane from the cab while he is at 

 work; safety couplings, brakes, and bumpers are specified; also a 

 gong which the operator can ring to warn anyone underneath of the 

 approach of the crane; a brush or prong is required which moves 

 along the track in front of the crane wheel, and would push aside 

 a hand or foot resting on the rail of the runway before it would be 

 crushed by the wheel. Wire ropes are also specified for hoisting 

 purposes instead of the chains which have been used largely in the 

 past; the failure of a single link in a chain means dropping the load, 

 while several members of a wire rope may be broken without inter- 

 fering with its service, and the broken strands give warning of weak- 

 ness which would not be apparent in a chain. 



One of the most important safety provisions for a crane is a foot- 

 walk on the bridge (see pi. 4, fig. 1), for the use of the crane operator, 

 who must go all over his crane every day or two to oil and inspect it, 

 and for the repairmen, who must handle tools and remove and replace 

 parts of the crane. Where a footwalk is not provided, it is necessary 

 to walk on the upper edge of the girder, the surface of which is 

 bisected by a rail and broken up by rivets and bolts, and is, more- 

 over, frequently slippery with grease or oil which drips from the 

 bearings. If mention is made at the time the order is placed, any 

 of the standard crane builders will furnish a footwalk on the crane ; 

 but of course it adds slightly to the cost, and in view of the com- 

 petitive bids on such work, it is only natural that the footwalk should 

 be omitted if it is not distinctly specified. 



Where these general matters have not been considered in designing 

 and arranging the different parts of a crane, it is difficult, and some- 

 times impossible, for an operating company to make all of the above 

 safety provisions, but whenever practicable they are being installed 

 on our old equipment. 



FOR WIRE DRAWING EQUIPMENT. 



Plate 5 shows the arrangement of a modern wire mill. A coil of 

 rods or wire is placed on a reel, from which it is drawn through a 

 die to a revolving block, the opening in the die being smaller than 



