U.S. Department of Labor

Mine Safety and Health Administration 4015 Wilson Boulevard Arlington, Virginia 22203-1984

ISSUE DATE: March 23, 2001

PROGRAM INFORMATION BULLETIN NO. P01-4

FROM:           MARVIN W. NICHOLS, JR.
                        Administrator
                             for Coal Mine Safety and Health

SUBJECT: Hoist Examination and Safety Test Requirements

Scope
This information bulletin applies to coal mine operators, independent contractors, and Coal Mine Safety and Health (CMS&H) inspection personnel.

Purpose
This bulletin reminds the coal mining industry of the required examinations and tests of hoist equipment safety devices. Improper tests and examinations could lead to a potential safety hazard.

Information
The investigation of a recent double fatal accident revealed that a rail mounted hoist man-trip brake car ran away after a hoist rope failed and the overspeed safety devices installed on the brake car failed to operate. Mine operator compliance with the examination and test standards can detect unsafe conditions and lead to their prompt correction. This bulletin clarifies coal mine operators' compliance responsibilities for examining, testing, and maintaining equipment used to transport persons under the applicable 30 CFR Sections 75.1400 and 77.1400.

1. an examination of the rope fastenings for defects;



2. an examination of safety catches;



3. an examination of the cages, platforms, elevators, or other devices for loose or missing or defective parts;



4. an examination of head sheaves to check for broken flanges, defective bearings, rope alignment, and proper lubrication;



5. an observation of the lining and all other equipment and appurtenances installed in the shaft; and

1. an examination of the rope fastenings for defects;



2. an examination of head sheaves to check for broken flanges, defective bearings, rope alignment, and proper lubrication; and



3. an examination of the automatic controls and brakes required under Section 77.1401.

1. Lift brake car until the wheel units that drive the overspeed devices are off the rail.



2. Securely block the brake car to prevent movement.



3. Drive the wheel units that are connected to the centrifugal overspeed devices to 115% of rated hoist rope speed to verify the overspeed operation and activation of the safety catches. Verify with a speed indicator, set to feet per minute, that both overspeed devices cause the overspeed safety catches to operate within their specified range.

1. Load brake car with rockdust or sand bags to simulate normal mantrip load capacity.



2. Disable overspeed device on the main hoist.



3. Run loaded brake car down the slope at 115% of rated rope speed. Verify that each overspeed device independently activates the safety catches and causes the brake car to stop and hold the fully loaded brake car.



4. Check the hoist depth indicator speed (feet per minute) to determine that the overspeed devices activated the safety catches within their specified range.



5. When brakes are applied with brake car on the slope, do not release the brakes unless the hoist rope is tight or the brake car is held by other means.



6. Push the off switch on the brake car to release the brakes.

1. Check brakes to see that they are adjusted to 1/4" to 3/8" above the rail and that they move freely on their supports.



2. Check the battery charge with a hydrometer. A fully charged battery will be between 1.225 and 1.260 specific gravity in each cell.



3. Check condition of V-belts driving the centrifugal overspeed switches, and ensure that belt tightener moves freely (some brake cars have magnetic motion overspeed detectors).



4. Manually close each centrifugal overspeed switch independently and activate the safety catches.



5. Push the off button to release brakes.



6. The circuit breaker mounted vertically on the control panel provides short-circuit protection. This should be closed at all times.



7. Close the circuit breaker next to the ammeter. The red light will go on and the car is ready for operation. This switch should be opened when the brake car is not used for a while, but must be closed when charging the batteries.



8. Push the ON button to apply brakes. All brakes should go down on the rail and the ammeter should indicate 85 to 90 amps. The white light should be on.



9. Push the OFF button to release the brakes.



10. Push the UP button to establish the roll-back circuit. The green light will go on. Move car inby and see that brakes are applied.



11. Push the OFF and DOWN buttons to release the brakes and deenergize the roll- back circuit.



12. Once the cars have been put in service at the start of the shift, the only attention needed is to push the UP button before starting up the slope and the DOWN button before going down.



13. If the control circuit fuse blows or the panel mounted circuit breaker opens, the brakes automatically will be applied through the fail-safe circuit. The white light will be on and the ammeter will not show discharge. After removing slack from the rope, open the circuit breaker next to the ammeter to release the brakes, and correct the faulty circuit.