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         continued from page 30                 SLINGUARD PROTECTORS
         the machine at high costs. In the course
         of time more and more manufacturers
         did not remove the preforming head                          “Clutch Action”
         from the machine.
           Going back in time to gather up some
         loose  ends – no  pun  intended – John                “The Only Proven Protection
         Lang was the production manager of
         R.S.Newall & Co. in England. He stud-                For Your Products and Slings”
         ied the  wear  characteristics  of  wire
         ropes and found out that the free length              Extends Sling Life - Reduces cost
         of a single wire would increase on the
         surface, if the wires in the strands were
         twisted in  the  same direction  as  the                Sleeves, Wraps, Pads
         strands in the rope. From this finding
         he also concluded that the pressures in                           & Blankets
         the sheaves would be distributed along
         a greater length,  which  would reduce
         the amount of the pressure and conse-                                Available From:
         quently reduce the wear.
           That was John Lang’s error. It is true
         that the wire  showed a greater free                    THE VERNON CORPORATION
         length on the rope’s surface. But Lang                     P.O. Box 246 • 400 N. Yankeetown Road
         failed to realize that for this reason the                        Boonville, Indiana 47601
         wire  appeared less  frequently  on  the
         surface. He may be pardoned though.
         Even  today his  error  can  be  found  in       (800) 897-5584
         the  publications  of  many  a  firm.  His
         ideas led however to the development
         of the Lang lay rope for which he was
         granted a patent in 1829.
           His employer R.S.Newall & Co. was
         not impressed by the advantages of the
         Lang lay rope and therefore John Lang
         joined Craddock Company and granted
         them the exclusive right to manufac-
         ture ropes of his patented  design. In
         the English-speaking world these ropes
         are still called Lang lay.
           In the long term ropes made of high-
         tensile  fiber  may  eventually  displace
         wire  ropes  in  many  fields  of  applica-
         tion. They are lighter, not susceptible
         to corrosion and – at least a number of
         them – surprisingly  fatigue-resistant.
         In  other  fields,  however,  steel  wire
         ropes no doubt will  maintain their
         place for the predictable future:  after
         all, wire ropes have a higher modulus
         of elasticity and are less  sensitive  to
         scraping  and mechanical  impairment
         than their light-weight rivals.
           What is more, in contrast to numer-
         ous ropes of high-tensile materials, steel
         wire ropes are tolerant of ultraviolet ra-
         diation as well as reliably showing their
         condition prior to the point of needing
         to be discarded. Their most crucial as-
         set, however, is the fact that the makers
         and users of wire ropes can lean on the
         in-the-field  and  real  time  education  of
         nearly 170 years of wire rope history –
         and there will certainly be more to learn
         in the coming decades. WRN

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