Tension Monitors - Ropetalk

2016 04 13 11.45.08

Monitoring tension of your cables in a logging operation makes good sense from a safety and productivity perspective.  Overloading wirerope is simple to do especially where the ropes are held tight however the converse is also true that without good knowledge of rope tension it is possible to underload.  In the absence of a system to monitor tension the skyline brake is designed to slip as the safety mechanism, this is not always reliable especially in older machines.  Knowing tension helps maximise payload for each cycle and therefore is a measure of effective extraction while staying within safety limits.  However it is likely that at some point appropriate tension (as per the ACOP) will be exceeded and knowing this allows you to put additional measures in place to reduce the risk of mishap.  Sending a breakerout in to untie trees where tension exceeds safe working load by a small margin would be ludicrous and therefore additional procedures such as slowing the inhaul or watching guyline anchors during  inhaul might be more appropriate.  

Initially safe working load was designed more around rope life.  Safe working load limits of a third the breaking strain meant that spikes in tension could be accommodated without damaging the rope.  However the ACOP says that all loadbearing wirerope shall not exceed 1/3 of the minimum breaking strength.

Ropetalk was designed to measure the tension with the additional benefit of logging the tension data.  The features of ropetalk include;

ropetalk2

  • Pre-calibrated for 4 different rope sizes so if ropes are changed for any reason the new rope size can be selected from a menu without needing a recalibration.
  • The sensor is calibrated on a certified test bed.  Cert page 1 and cert page 2.
  • The sensor weighs 34kg and therefore is not too arduous to remove before towering down.
  • The sensor and display communicate wirelessly
  • The tension in tonnes is displayed in easy to read numbers and turns red if overloaded.
  • A fish finder type graph is also displayed so recent history can also be reviewed
  • The system does not have an audible alarm system if an overload occurs as it is expected the operator will watch the tension through the critical part of inhaul
  • The display tension is stored and the memory is big enough to store 18 to 20 years of data.
  • The data is downloadable by the user and can be deleted from the system all with a smart phone
  • The sensor is powered by battery during the day and can be trickle charged using a lead from the hauler battery with no risk of flattening the hauler battery 
  • The sensor is totally wireless during operation
  • The sensor is able to read 3 to 8 readings per second
  • Mounting brackets are not supplied
  • A parts only warranty applies

 tension screen