SPT Hammer Energy Measurement

A field measurement system and procedure which measures the energy delivered by a drill rig system was developed and successfully used to study the factors which affect delivered energy. Results are presented which indicate that the energy delivered by certain drill rig systems varies widely in engineering practice. The energy delivered to the drill stem varied with the number of turns of rope around the cathead, the fall height, drill rig type hammer type, and operator characteristics. The type of hammer had a strong influence on the energy transfer mechanism between the anvil and the drill stem. It appears that the safety (sleeve enclosed) hammer is more efficient in transmitting the available kinetic energy through the anvil to the drill stem than the donut hammer.