NOTES ON CHAIN CABLES. 163 



of greater accessibility and ease of woi'king, but it is noted in the case of 4>4-inch 

 English chain made under the steam hammer, the dies are for end welding. 



I am of the opinion that with the increasing size of our chain and the evident 

 necessity of developing a power process involving die welding under a hammer, the 

 end weld will be more easily and successfully made and in all respects superior to the 

 side weld. 



The advantages of the end weld over the side weld would therefore appear to 

 be— 



( 1 ) Greater uniformity in distribution of stresses and in deformation. 



(2) Form of link assists the weld to resist parting stresses. 



(3) Greater facility in heating. 



(4) Greater facility in working in dies. 



PROCESS OF MAKING CHAIN. 



A great number of patents have been taken out covering the manufacture 

 of chain or some operation incident thereto. Such patents have been successful 

 commercially only in so far as they have been applied to chain of smaller sizes 

 up to 1% inches, and to chain of inferior quality. Chain larger than 1I4 innches 

 and high-grade chain are to-day made, for the most part, by a hand process. 



In the case of large hand-made side-welded chain, the links have been quite 

 successfully bent by machine, but in the case of end-welded chain, even this has 

 not been accomplished. The side-welded link is much easier to form or bend than 

 the end-welded link, as the bends come further from the end, and so there is a 

 longer leverage to work with. In spite of this advantage, the end weld is consid- 

 ered preferable for reasons already stated, which have to do with ease and certainty 

 of welding. 



In order that work involved in making chain may be fully understood, a de- 

 scription is here given of the process followed by the "hand" chainmaker on 3-inch 

 chain. 



The bolt is about 37 inches long and weighs about 78 pounds. It is furnished 

 the chainmaker cold and straight with both ends sheared square. He places it in 

 a coke fire and brings it up to a working heat. As his fire is not large enough to 

 heat the whole bolt, it is necessary for him to heat one end at a time and turn it 

 end for end until the whole bolt is heated with the hottest point at the center. 

 This requires about 14 minutes, and the material is somewhat damaged by oxi- 

 dation as the ends are exposed to the air upon being turned. A photograph of the 

 fire with bolt in it is shown in Fig. 12, Plate 92. 



The bolt is then bent into a "U" shape about a mandrel by means of the cap- 

 stan bar arrangement shown in Fig. 13, Plate 91. The work is done by the chain- 

 maker's helpers, as shown in Fig. 14, Plate 92. 



On the same heat, the ends are thrown in slightly by hammering over the 

 edge of the anvil, as shown in Fig. 15, Plate 93. This work, including bending, re- 

 quires about two minutes. The -bolt is then re-heated for scarfing, requiring 



