Page 69 - Wire Rope News & Sling Technology - August 2019
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                                                              man machine interface 34 and external data input 36. In the
                                                              embodiment  shown,  lifting system  12 includes  sheave  13.
                                                              In other systems, lifting system 12 can include one or more
                                                              winches and/or from zero to two sheaves. Sheave 13 of lifting
                                                              system 12 are mounted on the vessel and crane to guide and
                                                              bend rope 16 from lifting system 12 to lifting systems hook.
                                                              Rope 16 is a rope made of a plurality of strands. Rope 16 can
                                                              be made of wire strands, for example steel wire, or can be
                                                              made of fiber strands. In some cases, grease is used between
                                                              the strands of the wire. Different sensors 18, 20, 22, 24 may
                                                              be used depending on the material forming rope 16.
                                                               AHC system 14 is often used in offshore systems where
                                                              water  depths  range  from  about  40 to  about 3000 meters.
                                                              AHC systems are especially useful  in systems where  the
                                                              water depth is very deep, for example, 2-3 kilometers, and
                                                              when  used  with  voluminous  and/or  large  objects  to  assist
                                                              in a smooth transition a few meters before touchdown on
                                                              the seabed or in a splash zone. AHC system 14 compensates
         Figure 20: Gear mechanism with the crank attached to the outer gear.
                                                              for the motion of the vessel on the waves (or for the waves
         may be operated by the user. This outer gear turns a small-  in  the  case  of  lowering  through  the  splash  zone),  keeping
         er gear (in this case three) that turn the central gear which   load 17 motionless with regard to a fixed position such as
         turns the cord spool attached to it, producing a 5:1 crank to   the seabed. The compensation movements by AHC system
         turn ratio. The centering of the gear setup can be achieved   14 results in a friction in rope 16, and particularly between
         by using three or more, evenly sized gears between the outer   strands making up rope. This friction can heat up rope 16
         gear and central gear. The attached spool can become heavy   and can cause the grease in rope 16 to melt off and/or cause
         and/or out of balance as a cord is wound, the centering of the   other fatigue problems.
         gear setup helps maintain the smooth rotation of the spool.   Rope data sensor 18 can be a cross-sectional measurement
         The  gear  mechanism  can  also  accommodate  a  1:1  ratio  or   device such as a contactless electromagnetic wire rope in-
         even negative i.e. 1:2 ratio when the weight of the cord is an   spection sensor, for example, the LMA-Test system manu-
         issue and greater torque rather than speed is preferred.   factured by NDT Technologies, Inc. in South Windsor, CT.
           Different speeds of operation can be achieved by moving   In other embodiments, rope data sensor 18 can be another
         the crank handle from the center gear to the outer gear or   type of sensor and/or can measure the physical state, elon-
         vice versa based on the requirement. The ratio produced by   gation, creep and/or appearance of the rope through other
         this reel makes rolling up a cord much faster but the concept   means.  In  the  embodiment  shown  in  figure  21,  rope  data
         is not limited to this style of reel. Adaptations for reels of   sensor 18 is connected to rope 16 within lifting system 12.
         many sizes and styles are applicable and the optimal ratio   This ensures that any rope 16 running through lifting sys-
         necessary for each type can be achieved by altering the gear   tem 12 for use is monitored by rope data sensor 18 so that a
         size relationships. The central gear may also be hollow, al-  physical property indicating rope status is sensed and sent
         lowing the cable to pass through after exiting the center of   to computer system 26.
         the spool. This allows a cord end to be accessible while the   Tension sensor 22 measures the tension in rope 16, and
         spool attached winds the rest of the cord.           temperature sensors 24 measure the temperature at a bend-
                                                              ing point of rope 16. Other embodiments can have more or
         Real-time rope monitoring                            fewer rope usage sensors to collect other data regarding us-
         Pat. 10,317,389 U.S. class B66B 7/1215 Int. class G01N 33/36  age of the rope, for example, diameter and/or shape of the
         Inventor:  Frederik  Benjamin van der  Woude,  Culemborg,   rope. Some systems 10 can include sensors related to outside
         NL., Jurgen Arjan Zijlmans, Barendrecht, NL.         factors, such as the sea state or weather conditions in which
         Assignee: IHC Holland IE B.V., Sliedrecht, NL.       vessel is working during operations.
           This patent presents a system to monitor and analyze a   Position measurement device 20 can be a rope speed/sec-
         multi-strand rope includes a rope data sensor to collect data   tional displacement sensor, a measuring wheel, or another
         regarding the physical state of the rope; one or more usage   type of position sensor such as a contactless measuring sys-
         sensors to collect data regarding the usage of the rope; a po-  tem. Position  measurement device  20 works  so  that mea-
         sition  measurement  device to measure  the  position  of  the   surements taken by rope data sensor 18 and usage sensors
         rope; and a computer system connected to the rope data sen-  22, 24 can be accurately tracked and designated to corre-
         sor,  the one or more usage sensors  and the position mea-  spond to a particular section of rope 16.
         surement device to correlate the collected data and position   Computer system 26 can include a number of processors
         measurement to give real-time data on the status of the rope   and/or databases to receive information from sensors 18, 22,
         at one or more sections.                             24 and from position measurement device 20, store that infor-
           Figure 21 schematically illustrates rope monitoring and   mation, analyze it and use it for planning for usage, mainte-
         analysis system  10 in use with lifting system  12 and ac-  nance and/or replacement of all or sections of rope 16. In the
         tive heave compensation (“AHC”) system 14 for rope 16 to   example shown in figure 21, computer system 26 includes a
         raise and lower load 17. Rope monitoring and analysis sys-  rope data sensor processor and database 30 to process and
         tem 10 includes rope data sensor 18, position measurement   store data from rope data sensor 18; a lifting system proces-
         device  20, tension  sensor  22, temperature sensors  24 and   sor and database 28 to process and store data from position
         computer system 26. Computer system 26 includes lifting   measurement device 20, tension sensor 22 and temperature
         system processor and database 28, rope data sensor proces-  sensors 24; and overall processor and database 32 to receive
         sor and database 30, overall processor and database 32, hu-                           continued on next page

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