Page 20 - Wire Rope News & Sling Technology - December 2018
P. 20

continued from page 18
         cause  it  was  the  first  launch,  we  had
         no reference.”
           “The system worked! The train came
         back into the loading area, and every-
         one was applauding and so on.”
           Yet,  something  had  gone  terribly
         wrong. Almost immediately after the
         train stopped, Teissier and a colleague
         inspected  the  cable  below  the  train.
         As they listened to the applause and
         clinking  of champagne glasses  above
         them, the two men discovered that the
         rope had slid inside the attachment.
         “If you have slippage it means the at-
         tachment is not strong enough. I can
         tell you that when we noticed this, it
         was  a  very  difficult  moment.  And  I
         thought, ‘This is not good.’”
           It wasn’t until they investigated fur-  Jean-Marc (left) works on the inclined lift of the Eiffel Tower.
         ther  that they realized  the  problem.   lem was solved.             the configuration of 145,000 cycles be-
         The  acceleration  had  been  set  incor-  When asked if he’d had any sleepless   fore the discard of the rope. At Disney
         rectly. The acceleration should have   nights worrying if it would work, Teis-  in Paris you have a huge season in the
         been set for .8G. Instead, the train had   sier responded, “Yes. Plenty.  summer and much activity for Christ-
         sped forward  at 8G,  which,  of  course,   “The biggest challenge was the ser-  mas. So after one or two years, the de-
         is 10 times the acceleration. “The train   vice life of the rope. The proposal was   cision was made to change the rope in
         was  launched  at the  maximum  accel-  to change the rope only once a year.   June  just  before  the  summer  season
         eration that the motors were  able to   But that was never possible. So from   and then again in November just be-
         do, and this was the reason why the at-  the beginning it was two times a year.   fore the Christmas holidays.” Inspec-
         tachment slipped.”                 Doing our best to keep within the re-  tions are performed daily, weekly, and
           Once that  was  corrected,  the  prob-  quired constraints,  we  came up with        continued on page 22

                      Understanding the Rope System that Powers the Space Mountain Catapult
             “When the passengers are seated and secured,  when   “…The background music is interrupted by a loud bang,
            the glasses have been taken off and the false teeth are   smoke comes out of the canon, and the train rapidly takes
            stored in the pocket, the train moves down to the bottom   off. Under the acceleration of 1,3g the passengers are
            of the canon slope by means of gravity.Ӡ         pressed into their seats and the train reaches a speed of
             Unaware of the rope  system  that  will  power their  as-  more than 50km/h in less than 2 seconds.” †
            cent, riders excitedly anticipate the amusement ride in the   The steel wire rope is Casar Turboplast. It has a nomi-
            dome above them, where they will travel in the dark at   nal diameter of 36mm with a wire grade of 1770 N/mm2,
            dizzying speeds.                                  and  consists  of  an  independent  steel  wire  rope  core,  a
             But first, their train, which consists of six cars, each   plastic layer and eight compacted outer strands.
            with four seats, will be literally catapulted into the dome.   “The rope ends are attached to the drum. As the drum
             The catapult  pusher, which is  a  carriage fixed  to  the   rotates, one rope end is wound onto the drum and the
            rope system below the train, moves the train into the de-  other end is payed off. As a result, the rope length stored
            parture position in the lower section of the track, which is   on the drum always remains the same: it corresponds to
            50m long and inclined by 32 degrees.              the length of the pusher stroke plus the required dead
             After a short waiting time, purposefully designed to in-  wraps. This configuration allowed the design of a very
            crease the tension of the passengers, the canon is fired.   short drum with only one wrap empty, resulting in very
             The rope reeving system rotates in a pretensioned, “closed   small fleet angles for the wire rope.”†
            loop” system, causing the pusher to launch the train.  After the rope travels from the drum through the push-
                                                              er, it is held by friction to the headstock sheave. There it
                                                  TRAIN LAUNCHED  is deflected by 180°.
                                                               Shortly before the summit of the slope is reached, the
                                                              pusher decelerates. The train enters the dome, subject-
                                                 HEADSTOCK SHEAVE  ing passengers to a short moment of weightless condition.
                                                              Then it shoots forward to continue along the track.
                       TRAIN AT          WIRE ROPE
                    LAUNCH POSITION                            The rope travels back to the drum via the mid-span sup-
                                                              porting sheave. And the pusher resets to its starting posi-
                                                              tion, ready to launch another train.
              TRAIN AT          PUSHER                         Meanwhile,  passengers  will  experience  the  start of
                                                              their breathtaking roller coaster trip. They will arrive 90
                                                              seconds later back at their point of departure.
                                                               †“Space Mountain at Euro Disney: A 120 million dollar wire rope test machine,” by
                                                              A. Arfa, A. Belleculée, G. Oplatka, J.-M. Teissier, Roland Verreet.

         20     Wire Rope News & Sling Technology   December 2018
   15   16   17   18   19   20   21   22   23   24   25