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 TRR1 rods retainer system that allows to add several rods on the feed, to drill longer holes.
Sandvik Rod Retainer TRR1 can be fitted on Sandvik Tunneling drills feeds (TF, TFi and TFX) with HLX5, RDX5 and RD500 series rock drills.
Additional rods have to be loaded manually in the gripper. A safety wire is installed near the TRR1 to allow immediate emergency stop in case of issue.
During coupling and uncoupling phase TRR1 is holding extension rods. TRR1 can be used either 32 mm (1 ¼ in) or 38 mm (1 ½ in) rods.
The design of TRR1 rod retainer aims at simplicity of structure and ease of maintenance. TRR1 is a robust welded steel structure with only one movable jaw piece. The jaw pieces are made of hardened steel and designed for optimum visibility and durability.
When TRR1 is installed on TF feed, hole depth is shortened by 35 mm. By cutting 35 mm off from the buffer hole depth can be restored. On telescopic TFX feed there is no effect on hole length.
The TRR1 conversion kit is delivered with all needed parts including, new controls (hydraulic or electro-hydraulic according machine model) and hoses harness.