Page 36 - Wire Rope News & Sling Technology - October2019
P. 36

1979-2019 Celebrating Our
                         40th Year Serving the Industry,

                               Wire Rope News & Sling Technology
                                   asks long-time experts to share
                                   memories and comments on…

               Our Industry Over the Past 40 Years



              Donald L. Pellow – P.E., Pellow Engineering Services, Inc.


                  hile it may seem that the Wire  is  higher  quality steel  of  rods  for  and IWRC’s is  the reduction  of  in-
             WRope Industry is  mature and  wire drawing. Not to be overlooked  ternal abrasion of the outer strands
             has not embraced changes over the  are the new designs of wire drawing  against the core ... less wire wear.
             last 40 years, it only takes a few  equipment and manufacturing prac-  One other advancement which has
             moments  to  realize  the  significant  tices.  As  an example, newer  wire  proven highly successful  in reduc-
             modifications  and  advancements  drawing machines operate at faster  ing  radial  pressures  of  wire  ropes
             that have taken place. Many innova-  speeds, while at the same maintain-  against drums  and  sheaves,  while
             tions have been introduced into the                              increasing resistance to drum crush-
             various markets served by wire rope                              ing,  is  the use  of compacted outer
             manufacturers  and distributors.                                 strands and IWRC’s  in the manu-
             This includes new wire rope designs                              facturing of wire rope. There are
             and applications.                                                test data and field reports that sub-
              New wire rope designs, mostly re-                               stantiate that the fatigue life of such
             lating to cranes used in long fall lifts,                        compacted strand wire  ropes  has
             involve rotation-resistant properties,                           increased; that is, there is a slower
             while  incorporating  higher  strength                           development of  wire  breaks  due  to
             levels. Newly highly engineered wire                             fatigue . This phenomenon is known
             ropes provide minimum to almost                                  as “mechanical stress-relieving” and
             no rotation or block spinning on lifts                           is the result of compacting or flatten-
             of hundreds of feet overhead. These                              ing the surfaces of the outer wires of
             wire rope designs of higher strengths,                           wire ropes and IWRC’s.
             superior resistance to spinning and                               One final comment is that the use
             block rotation and with enhanced                                 of  wire  ropes  in  some  applications
             resistance to drum crushing were                                 has experienced limited competition
             successful  by  corroboration  of  crane                         from  high strength polymers and
             manufacturers and wire rope manu-                                high  density  fiber  ropes.  However,
             factures. This was a perfect blend of  ing lower  frictional  heat resulting  new and expanded applications em-
             advanced wire rope technology and  in reduced wire temperatures, thus  ploying wire rope have emerged, so
             the industry requirements of newly  leading to improved wire  quality  wire  rope  is  not  a  dinosaur.  These
             designed cranes.                and higher strength levels.      expanded uses of wire rope include
              The  strength  levels  of  wire  ropes   Another noticeable leap forward  more cable supported  bridges; the
             over the last forty years have evolved  in wire rope design and manufactur-  expanded use of tower cranes speci-
             from  plow  steel  to Improved Plow  ing is the innovative use of plastic or  fying multiple-layer, high strength
             Steel to Extra Improved Plow Steel  polymer materials to either coat the  wire  ropes;  and architectural  and
             and to Extra, Extra Improved Plow  outer surface of the wire ropes and/  structural  components  of  modern
             Steel. Achievement of the higher  or in coating the Independent Wire  building designs. n
             strength levels of wire rope was pos-  Rope Cores. These coated wire ropes
             sible with dramatic  improvements  and IWRC’s prolong the service life   This is the final installment of our 40
             in  the  strength  and quality of  the  of wire ropes during the loading and   Year celebration. I hope all our readers
                                                                                enjoyed this trip down Memory Lane
             wire  being incorporated into wire  bending cycles  experienced as they   and we look forward to the next
             rope manufacturing.  One critical  operating on cranes and other appli-  generation of industry leaders to share
                                                                                their thoughts on how the industry
             element in obtaining higher quality  cations. Another inherent benefit of   changes in the upcoming 40 years! -Ed.
             and strength of high carbon wires  polymer or plastic coated wire ropes


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