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PERSONNEL AND MATERIAL TRANSPORT |
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Roadway Maintenance |
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Roadway Maintenance
Whether rail or free steered transport is used, the importance of roadway maintenance cannot be stressed enough.
Provided there is no floor heave, maintenance of rail is somewhat simpler and entails ensuring clearance is adequate at all times, the trackwork is securely held on the sleepers and fishplates at rail joins are tight (some mines use welded joints, often using a chemical welding process rather than oxy or electric welding). Looseness in trackwork may not be readily apparent and will not cause problems up to the point where joins break or gauge is too large or small, causing a derailment, but a derailment can be catastrophic. Constant attention to trackwork condition is therefore essential. Rails are subject to wear and corrosion and may require replacement at times.
If floor heave occurs it will be necessary to brush the floor to maintain a reasonably level grade across the tracks.
It is important water be kept off the rails as rail mounted equipment is prone to skidding on wet rails (this does not apply to rail transport attached to a winding rope in normal use but can affect the adequacy of a dump brake system).
Rubber tyred vehicles can handle poor conditions and limited roadway clearance, but the conditions will greatly affect speed, vehicle reliability and maintenance costs and passenger health and safety. It is now accepted practice to build and maintain rubber tyred vehicle travel roads using a road grader to grade whatever floor material is available, and to also use ballast and road base to complement existing floor material in localized problem areas. Floor construction and maintenance has been recognized as so important that grading is usually a principal occupation for at least one employee at a mine.
It is noted that coal fines packed down will make a good road surface but may become a problem dust source if allowed to dry out.
It is important to keep water off rubber tyred vehicle travel roads as ponding or running water will cause roadway surfaces to deteriorate rapidly. Trenching is therefore employed at some mines to trap water make and minimize the impact of water on floor conditions. At the same time, some dampness is required to keep any make of dust low. Some mines 'salt" travel roads to assist in dust suppression and roadway consolidation.
It is also noted that one mine has introduced the practice of progressively concreting the longwall maingate travel roadway during development to counter soft floor conditions and a high water make from the seam and surrounding strata. Such measures are reported to have significantly improved availability of rubber tyred equipment, reduced travelling times and ensured the continuity of supply of materials to the working area.
Good housekeeping is important on rubber tyred vehicle travel roads as any material left on the road can be easily thrown up causing injury to personnel or damage to equipment.
Dust Control Solutions Australia – road surface stabilization