Scaling, the removal of loose rock from the roofs and walls of a mine by manual or mechanized means, may be necessary during any stage of mining. Manual scaling is very labor intensive, and mechanical methods can be too powerful and actually produce a less stable roof. A systematic review of recent MSHA accident and fatality reports for underground metal/nonmetal mines revealed that nearly a quarter of all fatalities were related to rock falls, approximately one-third of all accidents involved scaling, and about half of all scaling-related accidents involved miners with less than 3 years of mining experience. Thus, the process of scaling was identified as a major source of injuries to miners and targeted for investigation.

Stephen B. Thacker CDC Library collection
National Institute for Occupational Safety and Health