Case Study 6
Locating a lost drill head
– HDPE
– Ø 75mm (3”) ID
– Length : 126m (415’)
– Depth : 5m (15’)
A contractor was attempting to install a telecom duct by means of pipe ramming. The designed profile was virtually straight, but when the calculated length of pipe was reached the drill head did not appear in the receiving pit. Assuming the drill head must have drifted to the right, multiple holes were dug in the Initial Search Area. However, the drill head remained lost.
A local Reduct customer was commissioned to perform a gyro survey. Because the pipe’s end-point was unknown, the field crew made some operational adjustments to enable the DuctRunner to work with only an entry point, a method supported by the DuctRunner software. After processing the data on-site, the end point of the measurement was marked by a stake, which suggested the drill head had drifted to the left, not to the right. After excavating to the measured depth, the drill head was found within several inches of the location of the stake.