Farrow's military encyclopedia : a dictionary of military knowledge . chain-wheel system, great effortmust be nuide to secure chains of perfectly uniformpitch. Chain-making is one of the few remainingmanual trades in which modern machinery has notto[a greater or less extent displaced tin- skill of theindividual workman. .Many atteinpts have beenmade to jjroduci; chains by machinery, and allhoitghsimie success has been attained, no nuichine-madechain has yet been produced having sufficient relia-bility and tmiforuuty of quality to adapt it to use incranes. The all-important opc^ration in chain-
Farrow's military encyclopedia : a dictionary of military knowledge . chain-wheel system, great effortmust be nuide to secure chains of perfectly uniformpitch. Chain-making is one of the few remainingmanual trades in which modern machinery has notto[a greater or less extent displaced tin- skill of theindividual workman. .Many atteinpts have beenmade to jjroduci; chains by machinery, and allhoitghsimie success has been attained, no nuichine-madechain has yet been produced having sufficient relia-bility and tmiforuuty of quality to adapt it to use incranes. The all-important opc^ration in chain-mii-king is the process of w<0<ling the links, and in thisthe personal element seems indispensable to a per-fect result, no machine, however perfect, taking theplace of the skill and intelligence of the workman. As used in the Weston cranes, the pitch-chains ofthe smaller sizes are made entirely of Norway iron,while for the larger sizes either the Xorway ironor American iron of high elasticity and rluctility, isused. Each link is forged and welded with great. Fig. 2. care, and much more time and labor is expended onthis part of the work than is the case with commonchain. All of this pitch-chain is made under aj patented process, which consists in forging thechain slightly under pitch, after which it is tirstcleaned and brightened by rattling, and thenstretched in a special machine to the final gauge orpitch. The lirst process causes the several links tocome into more perfect contact or bearing by remov-ing the scale and other slight asperities from th-drsurfaces. The second process assists in bringingtheir adjacent surfaces into closer contact, tends tostrengthen the sides of the links, and gives the irona sliglit initial set by straining it to a degree some-what greater than that which will be caused by theload which it is intended to ciirry. The final stepin the process is a carefid and rigid inspection ofeach link of the chain and the removal of any whichare at all imp
Size: 1367px × 1828px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade188, booksubjectmilitaryartandscience
