TRENCHING & BACKFILL
Because this is a deep trench, the wheel digger is accompanied by a 360 to restack the spoil as they go
Track playing is "Townsville Pipeline" By Tom Thomson
On short stretches, 360 diggers cut the trench.
The Padder in action. It scoops up spoil, and lifts that up onto screens, where large rocks are discarded over the back, and the soft fines are shot sideways by a conveyor belt, to ensure the pipe coating is not damaged by rocks.
On short stretches of backfill, this 360 with a riddle bucket sorts out the large rocks, and sprays the fines onto the pipe.
If the rollers can't reach, this digger with a whacker plate compacts the fill to just below ground level, and the gaspipe warning tape is laid.
This seems like agood point to meet the land drainage crew. Obviously, the pipeline destroys the farmers field drains, which now have to be replaced. First a small trench is cut, and a perforated plastic pipe is laid.
This shows the depth of the trench, and how the edges are automatically chamfered and compacted to slow down edge collapse. Click on the pic to see Seamus Tynan's Youtube clip of the trencher working
This is "Ossies Padder", in its usual state of waiting to go somewhere.
The Padder on a run.
After the trench has beeb backfilled, it is compacted by the vibrating rollers.
Then the trench is topped up to level with spoil, to await final ploughing and topsoiling.
After the pipe is laid, the trench is filled with gravel.