Underground » Maintenance
BMT have designed and manufactured an instrumented load sensing pin for the purpose of evaluating tow force data under typical underground operating conditions and various towing configurations. Unfortunately, due to mine constraints, data was only able to be acquired under a single towing configuration (CT-10 towing a wheeled unit with a rigid connection). This document describes the motivation and methodology of this investigation and presents results of the acquired data.
Towing of heavy and light equipment is a vital part of coal mining and occurs regularly. The principle risks involved with the failure of towing components include:
- Uncontrolled release of energy when components fail-
- Safety Alert 156 Towing of longwall chocks almost results in fatalities, 13th February 2007, Queensland department of Mines & Energy,
- MSHA report CAI-2003-24, Fatal powered haulage accident, September 9, 2003
- Unplanned movements or loss of control when components fail-
- Safety Alert 217 Unplanned movement of towed equipment 9th January 2009, Queensland department of Mines & Energy.
In recent years there has been several incidents involving towing equipment resulting in the Department of Industry and Investment releasing Safety Bulletin SB09-03 Broken Pull Chain Results in Fatality on 23 September 2009 with the recommendation that all mines review their towing, pulling and snigging operations. Also in the recommendations is the requirement to consider 'potential impact forces on the towing system results from dynamic loading'.
Site inspection of towing equipment revealed a large proportion of equipment is damaged in a manner consistent with overload.