# Useful Engineering Design-Related Improvement Guidelines for Reducing Mining Equipment Maintenance Errors

Over the years, engineering professionals working in the area of mining industrial sector have developed many useful engineering design-related improvement guidelines for reducing the occurrence of mining equipment maintenance-related errors. Six of the guidelines are as follows [16,17]:

• Guideline I: Improve equipment part interface by designing interfaces in such a way that the part can only be installed correctly and provide necessary mounting pins and other appropriate devices for supporting a part while it is being bolted or unbolted.
• Guideline II: Make use of decision guides for minimizing or reducing human guesswork by providing arrows for indicating correct hydraulic pressures, correct type of lubricants or fluids, and flow direction.
• Guideline III: Improve items, such as warning readouts, indictors, and devices, for reducing or minimizing human decision making.
• Guideline IV: Aim to improve fault isolation design by indicating the fault direction, designating appropriate test points and procedures, and providing built-in test capability.
• Guideline V: Design to facilitate detection of human errors.
• Guideline VI: Make use of operational interlocks in such a way that subsystems cannot be turned on when they are incorrectly installed or assembled.

# Problems

• 1. What are the reasons for improving mining equipment reliability?
• 2. List at least 13 factors that impact mining equipment/system reliability.
• 3. What are the reliability-related measures for mining equipment? Define at least two such measures.
• 4. Assume that an open-pit system has two independent and identical shovels forming a parallel network. The shovel failure rate is 0.005 failures per hour.

Calculate the open-pit system reliability for a 50-hours mission and mean time to failure.

5. Assume that an open-pit system is composed of four components: dumper, shovel, working face, and dumping phase; and failure probability of each component is 0.06, 0.05, 0.04, and 0.03, respectively.

Calculate the open-pit system reliability if all its components fail independently and form a series network.

6. Assume that in question No. 5, the constant failure rates of dumper, shovel, working face, and dumping place are 0.004 failures per hour, 0.003 failures per hour, 0.002 failures per hour, and 0.001 failures per hour, respectively.

Calculate the open-pit series system reliability for a 150-hour mission and mean time to failure.

• 7. What are the factors that can affect the life of dump-truck tires? Describe each of these factors.
• 8. Discuss programmable electronic mining system failures.
• 9. What are the typical/common mining equipment maintenance errors? List at least 12 of these errors.
• 10. Discuss useful engineering design-related improvement guidelines for reducing mining equipment maintenance errors.

# References

• 1. Chadwick, J., Higgins, S., US Technology, Int. Min., September 2006, pp. 44-54.
• 2. Dunn, S., Optimizing Production Scheduling for Maximum Plant Utilization and Minimum Downtime: The Reliability Revolution, Presented at the Dollar Driven Mining Conference, Perth, Australia, July 1997. Available online at http://www.plantmaintenance. com/ops-shtml.
• 3. Dhillon, B.S., Mining Equipment Reliability, Maintainability, and Safety, Springer- Verlag, London, 2008.
• 4. Mukhopadhyay, A.K., Open-pit system reliability, Journal of Mines Metals and Fuels, August 1988, pp. 389-392.
• 5. Dhillon, B.S., Design Reliability: Fundamentals and Applications, CRC Press, Boca Raton. Florida., 1999.
• 6. Dey, A., Battacharya, J., Banerjee, S., Prediction of field reliability for dumper tyres, hit. J. Suif. Min. Reclamat. Environ., Vol. 8, 1994, pp. 23-25.
• 7. Balen, O., Off the road tyres: correct selection and proper maintenance, Journal of Mines Metal Fuels, Vol. 22, 1979, pp. 107-113.
• 8. Sammarco, J.J., Programmable Electronic Mining Systems: Best Practices Recommendations (in Nine Parts), Report No. IC 9480, (Part 6: 5.1 System Safety Guidance), National Institute for Occupational Safety and Health (NIOSH), US Department of Health and Human Services, Washington, DC, 2005. Available from the NIOSH: Publications Dissemination, 4676 Columbia Parkway, Cincinnati, OH 45226-1998.
• 9. Moody, C., Reliable conveyor belt design. Proceedings of the American Mining Congress, 1991, pp. 579-582.
• 10. Chaplin, C.R., Failure mechanisms in wire ropes, Engineering Failure Analysis, Vol. 2, 1995, pp. 45-57.
• 11. Kuruppu, M., Methods and reliability of measuring winder rope degradation, Mine Planning and Equipment Selection, April 2003, pp. 261-266.
• 12. Chaplin, C.R., Hoisting ropes for drum winders: the mechanics of degradation. Mineral Technologies, 1994, pp. 213-219.
• 13. Poffenroth, D.N., Procedures and Results of Electromagnetic Testing of Mine Hoist Ropes Using the LMA-TEST Instruments. Proceedings of the OIPEEC Round Table Conference, September, 1989. pp. 17-21.
• 14. Weischedal, H.R., The inspection of wire ropes in service: a critical review. Material Evaluation, Vol. 43, No. 13, 1985, pp. 1592-1605.
• 15. ASTM E157-93, Standard Practice for Electromagnetic Examination of Ferro-Magnetic Steel Wire Ropes, American Society for Testing and Materials (ASTM), Philadelphia, 1993.
• 16. Under, R.L., Conway, K., Impact of Maintainability Design on Injury Rates and Maintenance Costs for Underground Mining Equipment, in Improving Safety at Small Underground Mines, Compiled by R.H. Peters, Special Publication No. 19-94, Bureau of Mines, Department of the Interior, Washington, DC, 1994.
• 17. Dhillon, B.S., Safety and Human Error in Engineering Systems, CRC Press, Boca Raton, Florida, 2013.