Purpose: This manual describes reliable or preferred procedures or concepts of drilling and blasting conducted during rock excavation, in order to aid design and construction personnel in related matters (para 1-4). Drilling and blasting methods described herein are not to be regarded as official Corps of Engineers (CE) policy, but they should be of assistance to CE personnel in establishing policy. The manual is designed principally for the use of geologists and engineers who are given responsibilities in drilling and blasting projects. Such responsibilities may come either in the design or in the construction phase.