Case Study - Rope Shovel Trip Mechanism

P&H 4100XPC Queensland Coal 

A Queensland Coal Mine operates electric rope shovels, these machines suffered frequent production losses to dipper trip mechanism failure.  This had the effect of shutting down the shovels themselves and standing down of the haul truck fleets.  Revised and optimised system components, along with improved alignment overcame the problem. 

Challenge
A Queensland Coal mine operated Komatsu P&H 4100XPB/C rope shovels in overburden clearance.  The trip mechanism, that operates to release the load into waiting trucks, would frequently jam meaning the load would not release.  These failures meant unplanned maintenance shuts on the shovels and down-time for the associated truck fleet.  These losses easily run into hundreds of hours per year. 
The operator was looking for a system that would reliably release throughout its life and to operate without replacement for the 9-month service interval.

   
Solution
Zemek proposed a revised trip system with innovations designed to maintain trip system integrity throughout its service life. 
The Zemek system features-
Use of low friction Wearite polymer components in the mechanism.  These reduce steel on steel wear and friction loads on the trip mechanism. 
Latest generation steel components such as latch bar and lever.  These have been optimised as a result of thorough understanding of operational conditions.  These parts maintain alignment and function for longer and are more easily adjusted as wear occurs. 
Zemek site support to confirm all systems are correctly aligned at time of refurbishment or major service.   

  
Results
Zemek optimised trip system has provided a significant reduction in hours lost to mechanism failure allowed the site to more consistently comply with planned maintenance intervals. 
Shut down safety and duration has improved with use of Wearite polymer materials. 
Mass of parts is reduced to 1/8 that of steel.
Polymer parts do not present sharp hazards seen with worn metal parts. 

Customer Feedback
"We have made significant gains in equipment availability since fitting the Zemek trip system.  Change out times on many parts has been halved and safety improved."