Underground » Roadway Development
The primary objective of this project was to improve safety and to reduce the costs associated with failures of trailing cables on shuttle cars. A summary of related 'incidences' from the relevant authorities for the mines in NSW and QLD shows that up to 51% of the problems may relate to inadequate cable tension.
These objectives were met through the development of a cable reel system offering:
1. An increase to the minimum tension when reeling-in while providing a reduction to the maximum tension that occurs during the pay-out process.
2. Improved visibility for the operator.
3. Improved cable laying.
4. Reduced friction at the sheaves.
5. Improved protection for the cable.
Systems are offered as a retrofit for existing fleets and there are twenty-two vehicles operating at seven mines fitted with a Cable-Safe hydraulic system together with various features as determined through this project. All are operating successfully and in each case the total fleet is being progressively upgraded.
Two versions of a constant tension system (CT) were developed and prototypes were tested in above-ground conditions. Both systems performed to expectations but whereas the hydro-mechanical version is ready for under-ground evaluation, the computer-based system requires considerable investment to gain the necessary approvals.
Given the excellent performance of the simple Cable-Safe system, it is intended to continue monitoring and to introduce the more complex 'CT' system when the potential benefits become clearer. Applications for patents will be timed accordingly.
Information concerning this project has been disseminated through the presentation of a paper to industry associations and to individual mines. In addition, an audit system has been developed and is offered to all mines.