Page 22 - Wire Rope News & Sling Technology






Page 22 - Wire Rope News & Sling Technology
P. 22

continued from page 20               The length of rope to
         to the outside of the strand and the   be made was the same as
         ending wire to the inside. After a few   with a 4 strand rope, but
         turns around the ending wire this end   the lengths of strands to
         was also secured. Thus in the connec-  be made was 25% less.
         tion area the number of wires increased   He made a time trial to
         either from 3 to 4, or from 4 to 5, for a   show it would take about
         short length of the strand.        2  minutes  to  combine
           The second decision was to connect   4 wires into 1  “lachter”
         different sections  of rope using  the   of  “jedes  Stranges”.  The
         same or a similar technique. For test-  Lachter  was  the com-
         ing this he only had his short trial   mon measurement used
         lengths of 3 and 4 strand rope at hand,   for length in mining and
         but  that  did not  stop him. He  spliced   excavating. One Lachter
         the two different rope designs together   was the distance be-
         and then connected them to the hemp   tween a man’s hands
         rope which was installed in the “Caro-  when his arms were
         line” shaft. The two short rope lengths   held straight outward
         with  the splice  had already run  over   from his body.
         the capstan a few hundred times when   In order to further re-
         the bucket got stuck in the shaft and   duce production time Al-
         the hemp rope broke. The short 3 and 4   bert experimented with   A retired mine worker in 1980 explaining Albert’s ropemaking
         strand ropes and the splice connecting   doing both the strand-  at the Clausthal Mining Museum.
         them had proven to be stronger  than   ing and the closing  at
         the hemp rope!                     the same time. Three teams made one   study  on  June  3  confirmed  all  of  his
           Albert had to make a decision wheth-  strand each, while at the same time   earlier estimates.
         er he should use a 3 strand or a 4 strand   another team closed the rope. So on
         rope  for  the  first  field  trial.  Both  rope   one  side  of  the  floor  you  had  finished   “DER ERFOLG” = SUCCESS
         designs were made of the same number   rope,  on  the  other  side  you  had the   Although the shaft known as “Caro-
         of wires, they had the same breaking   strands and, further on, the wires. He   line” was the one chosen for the initial
         strengths  and  were  similarly  flexible.   even tried to start the rope production   attempt to employ a long wire rope for
         But production of greater lengths was   in the middle of the length, putting the   hoisting  ore,  Albert reasoned that it
         going to be difficult and would require   first meters of rope in a hair-pin type of   would make more sense if rope-making
         greater  floor  areas  and  employ  more   winding directly onto the drum of the   could be performed at a single location
         workers.  In  order  to  reduce  time  and   horsewhim,  and then fabricating on   near to all the mines, instead of mak-
         costs,  on  May  18  he  decided  to  do  the   two sides of the reel working outward   ing each rope individually adjacent to
         field tests with 3 strand ropes.   toward the rope ends! A follow-up time   the mineshaft itself. The best place
                                                                               seemed to be at the mineshaft known
         In 1990, Roland Verreet (l.) had a meeting with Mr. Olaf Schubert (r.) at the main gate of the
         Technische Universität Clausthal. Mr. Schubert is the person who discovered a surviving 4-strand   as “Dorothy”. On  June  8 he  noted he
         Albert rope being used as a fence around an abandoned mineshaft in the nearby forest.   had completed a 20 Lachter (approxi-
                                                                               mately 120-ft.) wire rope at “Dorothy”
                                                                               in the same time frame as he hoped for.
                                                                                 On July 22, 1834, one full page of
                                                                               his notes proclaimed a wire rope twice
                                                                               that long at the “Dorothy” shaft was a
                                                                               complete success!
                                                                                 In his public summary, as published
                                                                               by Dr. C. J. B. Karsten at Berlin, Albert
                                                                               reported as of April 1835 his wire ropes
                                                                               were already being used “…in four of the
                                                                               principal shafts of the Upper Harz. In a
                                                                               few weeks they will be employed in two
                                                                               shafts more, and they will be gradually
                                                                               adopted,  in  a  manner  compatible  with
                                                                               a due regard to the interest of those who
                                                                               have  heretofore  supplied  the  hempen
                                                                               ropes and iron chains. The adoption of
                                                                               the wire rope is a matter of essential im-
                                                                               portance for the mines of the Upper Harz,
                                                                               where more than 84,000 feet of rope (part-
                                                                               ly hemp and partly iron) are in constant
                                                                               work, and where every year upwards of
                                                                               38,500 feet of new rope are required.”
                                                                                 By emphasizing the crucial need for
                                                                               the innovative product but at the same
                                                                                                continued on page 24

         22     Wire Rope News & Sling Technology   June 2018
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