Introduction
Most HD machines can be fitted with suitable attachments to aid in drilling holes for soil investigation and geotechnical applications. They include sampling using standard coring and wireline techniques, U4 percussive sampling, and accurately drilled holes for inclinometers and extensometers. Special freefall winches with electric control as well as hydraulic spudding devices and cathead attachments are available. Suitable machines are the
HD50K-S,
HD70R and HD10. Also see
Environmental Investigation.