Air-inflatable Temporary Supports for Coal Mine Roofs.
NTIS: PB/223-597 Available for Reference At Bureau Libraries :73 pages
This report covers development of a temporary support system for coal mine roofs involving the use of overhead rigid spanners supported by pneumatically operated telescoping columns. Test data for individual components as well as for the entire system are reported. Data reported show that the system supports 80-100 pounds of thrust against the mine roof per pound of support as contrasted to a system of conventional mine jacks that support 50 pounds of thrust per pound of jack. As individual components, two of the pneumatically actuated telebeams supported a spanner load of 3 psi over an area of 2 by 18 inches.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB/223-597; Available for Reference At Bureau Libraries