Occasionally, it might be necessary to drill holes longer than the standard rod length used, i.e. drilling investigation holes, holes for grouting etc.
For this purpose, Sandvik has developed the TRS two rods system that allow to had safely a second rod on the feed.
The TRS can be retrofitted to TF feeds on tunneling drills.
The TRS consists of two grippers with cylinders to hold one rod at a time in jaws, a rod retainer to hold the rod during coupling / uncoupling (TRR1 or SCR) , an opening travelling centralizer to allow adding / removing rods from the center line, and a limit plate to help positioning the rods in the grippers.
The drilling starts with one rod in the feed, and another in the grippers. When the first rod is drilled, the second rod is placed in the feed by the grippers.
Additional rods can be loaded manually in the gripper. A safety wire is installed near the TRS to allow immediate emergency stop in case of issue.
The TRH conversion kit is delivered with all needed parts including, new controls and hoses harness.