TAMP//VG 

 DY/VAM/TE Pft/MEft 



BLOCKHOLING-CORRECT METHOD OF PLACING 

 CHARGE-HOLE BORED INTO BOULDER 



FIG. 130 



Table of Fuse Lengths 



This table is based on an average burning speed of Crescent Fuse of 3 feet 

 per minute. However, fuse that has been loosely rolled thus admitting more 

 air to the powder train inside the fuse, will burn more rapidly. Also, fuse in 

 tightly tamped holes, being under pressure, burns more rapidly. In extreme 

 cases the speed reaches 5 feet per minute. In subsoiling, as there is very little 

 material thrown up, the fuse may safely be cut just long enough to reach from 

 the charge of dynamite to a few inches above the surface of the ground. But 

 in stump blasting, ditching and especially in boulder blasting it is necessary 

 to use a fuse long enough to allow the blaster plenty of time to run far enough 

 away to be out of reach of flying stones or sections of stumps. When a safe distance 

 has been reached keep the eyes on the stump or boulder until the blast occurs, 

 then look upward for falling pieces. 



140 



