| Chapter 28 - Mine Maintenance |
| Number |
Topic |
Rule of Thumb |
| 28.01 |
General |
The degree of maintenance enforcement at an operating mine should be just less than the point that disruptions to operations are at a level where additional maintenance costs equal the resulting profits from production. Source: David Chick |
| 28.02 |
General |
In a trackless mine operating round the clock, there should be 0.8 journeyman mechanic or electrician on the payroll for each major unit of mobile equipment in the underground fleet. Source: John Gilbert |
| 28.03 |
General |
Emergency repairs should not exceed 15% of the maintenance workload. Source: John Rushton |
| 28.04 |
General |
LHD units at a shallow mine with ramp entry should have a utilization of 5,000 - 6,000 hours per year. Source: Unknown |
| 28.05 |
General |
Captive LHD units should have a utilization of 3,500 - 4,500 hours per year. Source: Unknown |
| 28.06 |
General |
LHD units in production service should have a useful life of at least 12,000 hours, including one rebuild at 7,500 hours. A longer life can be presumed from LHD units at the high end of the market with on-board diagnostics. Source: John Gilbert |
| 28.07 |
General |
Underground haul trucks should have a useful life of 20,000 hours; more if they are electric (trolley system). Longer life may be presumed in the light of today’s improved onboard diagnostics and better management of equipment maintenance in general. Source: John Chadwick |
| 28.08 |
Service |
An efficient Maintenance Department should be able to install one dollar worth of parts and materials for less than one dollar of labor cost. Source: John Rushton |
| 28.09 |
Service |
A servicing accuracy of 10% is a reasonable goal. In other words, no unit of equipment should receive the 250-hour service at more than 275 hours. Source: Larry Widdifield |
| 28.10 |
Infrastructure |
With ramp entry, a satellite shop is required when the mean mining depth reaches 200m below surface. A second one is required at a vertical depth of 400m. Source: Jack de la Vergne |
| 28.11 |
Infrastructure |
With ramp and shaft entry, a main shop is required underground when the mean mining depth reaches 500m below surface. Source: Jack de la Vergne |
| 28.12 |
Infrastructure |
A main shop facility underground should have the capacity to handle 10% of the underground fleet. Source: Keith Vaananen |
| 28.13 |
Infrastructure |
Service shops for open pit mines should be designed with plenty of room between service bays for lay-down area. As a rule of thumb, the width of the lay-down between bays should be at least equal to the width of the box of a pit truck. Source: Cass Atkinson |
| 28.14 |
Infrastructure |
Surface shops should be designed with one maintenance bay for six haul trucks having a capacity of up to 150 tons. This ratio is 4:1 for larger trucks. The shops should also include one tire bay and two lube bays. Additional maintenance bays are required for service trucks (1:20) and support equipment (1:12). Source: Don Myntii |