The Application of Boring Machines to the Production of Steeply Pitching Anthracite Coal.
For Reference Only At Bureau Libraries :21 pages
An evaluation was made of raise boring and augering machines for use in development and production in steeply pitching anthracite. This report concludes that raise boring and augering have potential for reducing costs in both development and production.
CP; Final Contract Report;
For Reference Only At Bureau Libraries
James H. Cobbs Engineering