Visual Inspection of Ropes in Mining Facilities - Minespect®
Visual inspection of ropes in mines
The hoisting ropes of a mining shaft are essential for bringing miners and material up and down as well as getting the ore to daylight. They are constantly on duty while any down-time of the winder causes immense costs. To ensure that the ropes are in good condition, they are inspected regularly.
Objectives of the visual rope inspection:
- Guarantee safety of operation
- Ensure operational availability
- Minimize and predict maintenance work
During a visual rope inspection with Minespect®, the following abnormalities are looked at:
- Reduction of rope diameter
- Increase or decrease in lay length
- Misplaced or loose outer wires
A visual inspection should be conducted daily, but the inspection of mining ropes is difficult due to various circumstances:
- Availability of trained/experienced inspection personnel
- Harsh conditions for highly qualified people due to dust or site contamination
- Speed of rope makes the inspection a difficult task e.g. diameter reduction or variations in lay length
- Downtime to conduct the inspection must be kept short, therefore problem areas are easily overlooked
Easy to imagine that an inspection may not detect a critical deterioration. Amongst these are:
- Wire breaks: Each broken wire reduces the strength of the wire rope (see EN 12927-6 or ANSI B 77.1-2011/ANSI M 11.1 for more details). The number of broken wires indicates the need for replacement.
- Rope diameter: After an initial reduction, the overall diameter will stabilize and slowly decrease during the ropes life cycle. But isolated and quick diameter reductions must be monitored to determine the cause of the diameter loss.
- Changes of lay length are an indication of torsion forces that weaken the life time of the rope
Minspect® is designed and optimized for the use at Koepe hoists to inspect several parallel hoisting ropes. Nevertheless, it can also be used on drum winder systems. Minespect® provides the customer with detailed documentation of each wire rope inspection. This allows to monitor the rope development and to improve maintenance planning.
When mining natural resources, the hoisting ropes are the core of every shaft transportation system. They are in constant use, as every interruption to mining operations causes considerable costs. The hoisting ropes undergo daily visual inspection to ensure that they are in perfect condition. Normally the inspection is carried out by two employees who check the rope as it passes by at a speed of 1 m/s. Damage can be overlooked quite easily, as this task demands a great deal of concentration while often being carried out under great time pressure. The inspection is time-consuming and thus causes considerable costs. In addition, due to inadequate documentation of the inspection results, the inspection is not verifiable. Furthermore, the inspectors are exposed to hazards during the inspection itself.
Afterwards the recordings are being analyzed by a patented software algorithm. Deviations of diameter and lay length as well as defects like wire breaks are being detected and highlighted by this software.
The responsible operations manager only has to evaluate the highlighted areas shown by the software and to review the graphs of diameter and lay length.