1. Standard CLG – Pipebursting Method Machine and insertion pits are excavated at the ends of the deviated sewer section and a rod pusher/puller and RSI Rotary AxiAnchor positioned in them. Laterals are exposed, disconnected and plugged.

2. Rods are inserted through the sewer, forming a guide shaft which is set in tension and then precisely aligned to required line and grade with the AxiAnchor. RSI AxiAligners may be used for grade adjustment at intermediate lateral or access pits. Standard CLG – Pipebursting Method

3. The sewer section is filled with a light cement slurry with a specified-time cure, set at between 4 and 24 hours. Open voids may also be filled. When the slurry has cured the guide shaft is encased in cement, on-line and on-grade, and the AxiAnchor and AxiAligners can then be removed. Standard CLG – Pipebursting Method

4. A pipebursting tool is fitted to the guide shaft and the new sewer pipeline, typically polyethylene fused to a single length, in turn fitted to the tool. The guide shaft is withdrawn by the rod puller, towing the tool along the correct line and grade path of least resistance, installing the new sewer by bursting both the cured cement slurry and the old sewer pipe. Standard CLG – Pipebursting Method

5. The new sewer is installed on specified line and grade, same size or upsized from the original. Standard CLG – Pipebursting Method

6. Standard CLG – Boring Method The operation proceeds as for pipebursting CLG except that an auger tool is fitted to the guide shaft which is rotated as it is withdrawn, driving the auger and boring a straight axis tunnel for the new sewer. A swivel connection is used between the auger and the new pipeline so that the latter does not also rotate.

7. The Pathfinder CLG Method The guide shaft is inserted through the pipeline with the Pathfinder rods located at points where the sewer is deviated by more than one pipe diameter. The ends of the shaft are positioned at correct line and grade points.

8. The guide shaft is put in tension and rotated with the tension constantly maintained. The Pathfinder rods bear against the inside wall of the sewer at the deviated areas and cut through the pipe out into the surrounding ground. The Pathfinder CLG Method

9. When the guide shaft is straightened at correct line and grade, tension is maintained while the sewer is filled with a light cement slurry. Once the slurry has cured, supporting the guide shaft in position, tension is released and the AxiAnchor removed. The Pathfinder CLG Method

10. Replacement of the old sewer, on-line, on-grade, then proceeds by standard CLG pipebursting or boring methods. The Pathfinder CLG Method

11. End views of sewer at Pathfinder rod locations at the four stages of the operation above. The Pathfinder CLG Method