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| Mining Field: Lateral Development and Ramps |
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Area: General |
| | • | Laser controls should be used in straight development headings that exceed 800 feet (240m) in length. Source: Tom Goodell |
| | • | The overall advance rate of a lateral drive may be increased by 30% and the unit cost decreased by 15% when two headings become available. Source: Bruce Lang |
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Area: Trackless Headings |
| | • | The minimum width for a trackless heading is 5 feet wider than the widest unit of mobile equipment. Source: Fred Edwards |
| | • | The back (roof) of trackless headings in hard rock should be driven with an arch of height equal to 20% of the heading width. Source: Kidd Mine Standards |
| | • | The cost to slash a trackless heading wider while it is being advanced is 80% of the cost of the heading itself, on a volumetric basis. Source: Bruce Lang |
| | • | For long ramp drives, the LHD/truck combination gives lower operating costs than LHDs alone and should be considered on any haul more than 1,500 feet in length. Source: Jack Clark |
| | • | LHD equipment is usually supplemented with underground trucks when the length of drive exceeds 1,000 feet. Source: Fred Edwards |
| | • | With ramp entry, a satellite shop is required underground for mobile drill jumbos and crawler mounted drills when the mean mining depth reaches 200m below surface. Source: Jack de la Vergne |
| | • | 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 |
| | • | A gradient of 2% is not enough for a horizontal trackless heading. It ought to be driven at a minimum of 2½% or 3%. Source: Bill Shaver |
| | • | The minimum radius of drift or ramp curve around which it is convenient to drive a mobile drill jumbo is 75 feet. Source: Al Walsh |
| | • | For practical purposes, a minimum curve radius of 50 feet may be employed satisfactorily for most ramp headings. Source: John Gilbert |
| | • | The gathering arm reach of a continuous face-mucking unit should be 2 feet wider than the nominal width of the drift being driven. Source: Jim Dales |
| | • | Footwall drifts for trackless blasthole mining should be offset from the ore by at least 15m (50 feet) in good ground. Deeper in the mine, the offset should be increased to 23m (75 feet) and for mining at great depth it should be not less than 30m (100 feet). Source: Jack de la Vergne |
| | • | Ore passes should be spaced at intervals not exceeding 500 feet (and waste passes not more than 750 feet) along the draw point drift, with LHD extraction. Source: Jack de la Vergne |
| | • | The maximum practical air velocity in lateral headings that are travelways is approximately 1,400 fpm. Even at this speed, a hard hat may be blown off when a vehicle or train passes by. At higher velocities, walking gets difficult and road dust becomes airborne. However, in pure lateral airways, the air velocity may exceed 3,000 fpm. Source: Various |
| | • | The typical range of ventilation air velocities found in a conveyor decline or drift is between 500 and 1,000 fpm. It is higher if the flow is in the direction of conveyor travel and is lower against it. Source: Floyd Bossard |
| | • | The maximum velocity at draw points and dumps is 1,200 fpm (6m/s) to avoid dust entrainment. Source: John Shilabeer |
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Area: Track Headings |
| | • | Track gage should not be less than ½ the extreme width of car or motor (locomotive). Source: MAPAO |
| | • | The tractive effort, TE (Lbs.) for a diesel locomotive is approximately equal to 300 times its horsepower rating. Source: John Partridge |
| | • | Wood ties should have a length equal to twice the track gage, be at least ¼ inch thicker than the spike length, and 1 3/8 times spike length in width. Source: MAPAO |
| | • | Typical gradients for track mines are 0.25% and 0.30%. Source: MAPAO |
| | • | A minimum clearance of three feet should be designed between the outside of the rails and the wall of the drift to permit safe operation of a mucking machine when driving the heading. Source: MAPAO |
Mining Rules of Thumb have been gathered over 30 years of hard rock mining service provided by Stantec / Mining and predecessor firms.
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