26.A.13 Ground support systems.
- Torque meters and/or torque wrenches must be used where rock bolts are used for ground support.
Drilling a roof bolt hole.
- Frequent tests must be made to determine if bolts meet the required torque. The test frequency must be determined by rock conditions and distance from vibration sources.
- Rock bolt support systems must be designed by a foundation engineer, geologist, geotechnical engineer, mining engineer or other qualified Registered Professional Engineer (RPE). Suitable protection must be provided for employees exposed to the hazard of loose ground while installing ground support systems.
- Support sets must be installed so that the bottoms have sufficient anchorage to prevent ground pressures from dislodging the support base of the sets. Lateral bracing must be provided between immediately adjacent sets to provide added stability.
- Damaged or dislodged ground supports must be repaired or replaced. Whenever possible, new supports must be installed before removing the damaged supports.
- A shield or other type of support must be used to maintain a safe travel way for personnel working in dead-end areas ahead of any support replacement operation.
26.A.14 Material handling equipment.
- Powered mobile haulage equipment must have audible warning devices to inform personnel to stay clear. The operator must sound the warning device before moving the equipment and whenever necessary during travel.
Vehicles must have a revolving light that is visible in all directions.
- All vehicles and mobile equipment required to move in and out of underground construction areas must have a revolving, flashing amber light, mounted so as to be visible in all directions. The flashing light must be on whenever a vehicle or mobile equipment is in operation.
- Haulage equipment must be equipped with two headlights at both ends, a back-up light, and an automatic back-up alarm.
- Conveyors used to transport muck from tunnels must be installed, guarded, and maintained as required by Section 17. Fire extinguishers or equivalent protection must be provided at the head and tail pulleys of underground belt conveyors and at 300 ft (91.4 m) intervals along the belt line.
- No person must ride haulage equipment unless it is equipped with seating for each passenger and passengers are protected from being struck, crushed, or caught between other equipment or surfaces.
- When dumping cars by hand, the car dumps must be provided with tie-down chains or bumper blocks to prevent cars from overturning.
- Where narrow-gage railroads are used for haulage, the tracks must be secured to prevent shifting. No "humping" of mine dump cars must be permitted.
- Whenever rails serve as a return for a trolley circuit, both rails must be bonded at every joint and cross-bonded every 200 ft (60.9 m).
- Mine dump cars must be equipped with automatic safety couplings, and cradle cars must be equipped with a positive locking device to prevent accidental dumping.
- Berms, bumper blocks, safety hooks, or equivalent means must be provided to prevent over-travel and overturning of haulage equipment at dumping locations.
- Bumper blocks or equivalent must be provided at all track dead ends.
26.A.15 Vehicles not directly involved in work must be kept away from portals and separated from construction activities.
26.A.16 A caution sign reading "BURIED LINE" (or similar wording) must be posted where air lines or other utility lines are buried or otherwise hidden by water or debris.
26.A.17 Where underground openings are located adjacent to sources of water with potential for causing flooding in the underground work area, measures must be taken to ensure that the underground area cannot be flooded.
Knowledge Check Choose the best answer for the question.
26-4. What is the interval spacing for fire extinguishers or equivalent protection along the belt line of underground belt conveyors?
You forgot to answer the question!