Examination of space/volume requirements for US underground coal mine refuge alternatives
ABSTRACT The Mine Safety and Health Administration requires that 1.4 m2 (15 ft2) of floor space is to be provided for each person inside a refuge alternative (RA). However, the amount of floor space needed for a person to reside inside an RA and perform basic tasks is unknown. During testing, participants entered into an RA or a simulated RA of various space/volume configurations and performed several simulated tasks that are representative of the survivability tasks performed within an RA. The results indicate that the floor space requirements were generally adequate for the tasks studied. Certain tasks such as changing scrubber cartridges, using toilets, and moving about the RA were impacted by the minimum height tested (0.6 m). As such, RAs of this height will require critical design consideration as a whole and the supplies provided for use inside of the RA to ensure the ability to use an RA.
The effects of restricted workspace on lumbar spine loading
Coal miners often handle heavy electrical power cables, weighing up to 10 kg per meter. These cables are manually lifted and attached to the mine roof to prevent damage from mobile underground equipment. Data suggest that workers who commonly perform cable-handling tasks experience a high rate of lost-time back injuries. In this study, six male underground miners performed a total of 12 cable-hanging tasks in standing, stooping, and kneeling postures, during which kinematic and ground reaction force data were collected. Reductions in vertical workspace were found to result in a linear increase in the peak moment experienced by the lumbar spine ( p 0.05). Average lumbopelvic flexion during the tasks was highest in stooping conditions, followed by standing and kneeling exertions ( p< 0.05). Implications of this data with respect to design of cable handling tasks are presented and discussed.
Spatial restraints and intra-abdominal pressure.
Fifty-four National Coal Board employees participated in an investigation of the effects of spatial restraints on acceptable manual-handling capacity. The particular spatial restraints considered were limited headroom, frontal and lateral barriers, asymmetric activities and fixed or trapped foot position. Each of these conditions was examined in isolation and then in combination with one or more further restraints. The findings, particularly from the interaction studies, revealed that a space limitation in some situations would inhibit the physical activity whereas in other conditions it might well enhance it, or at least reduce the associated back stress The predominant effect on acceptable handling capacity was found to be limited headroom where an almost linear decrement in capacity was demonstrated for roof levels down to 90% of stature, at which point the decrement began to level off Both frontal and lateral barriers were found to inhibit lifting activities in free space but under conditions of reduc...