ABSTRACT
A mechanical excavation tool, designed to supplement or supplant drill-blast methods of primary excavation, has been developed and successfully tested by the Bureau. The tool, called a radial-axial loading splitting tool (RASP), is as versatile in its application as drill-blast excavation methods, providing it with great potential while eliminating explosives and their associated hazards from the working environment. The RASP developed by the Bureau integrates a special hydraulic cylinder and three concentric rock-breaking components to achieve its excavation action. The success of the laboratory testing led to the development of a fourth generation RASP and a suitable carrier. Field testing of the full-scale RASP and tool positioner has shown that it is possible to devise a simple, efficient mechanical excavation machine using drilling and splitting tools. Because of the lack of long-term testing the maintenance requirements of RASP technology are not firmly established. However, the rock-breaking components require further testing before a definitive judgment can be made regarding their reliability.
