- When drilling, the TGZ reamer swings out and drills a hole wide enough for the casing tube to slide down
behind the reamer.
- When required depth is reached. the drill is reversed and the reamer swings in, allowing the bit to pass
through the casing.
3. Casing tube is puIIed out directly or fixed at the bottom of the hole by means of cement grout or other aggIutinant.
4. Drilling continues to the desired depth using conventional DTH equipment.