If you watched a pipeline crew come across a drain tile, it would be easy to grasp what “drain tile repair” means. The crew is forced to cut the drain tile (usually plastic but occasionally, PVC, metal, concrete or even clay). Then, presumably, they will repair the cut section by overlaying new tile to bridge the divided halves.
If only it were that simple.
Further investigation is needed before the crew can make the repair, otherwise there’s a chance that they would miss an important fix that could cause damage in the future.
Cutting the drain tile to make room for newly laid drain tile is an obvious place where tile damage can occur. Less obvious is how the preparation for the pipeline project can have an impact on subterranean drain tile.
Earth Moved, Earth Crushed
A significant amount of heavy equipment must cross the property as well before a pipeline can be laid. Earthmovers and similar equipment clear the land, to establish a right-of-way for the project to follow, and where transportation of supplies and equipment will take place.
A Caterpillar D9 bulldozer tractor weighs nearly 50 tons. That’s a lot of weight to be placing on hollow plastic tubing, even when that tubing is buried several feet underground.
As a result, it’s not unreasonable for the drain tile to collapse underground. A collapse dams up the tile system and causes the soil near the area to become waterlogged. This is a major issue for farmers, and those farmers could cause a huge headache for the pipeline company responsible for the damage.
Into The Deep
Therefore it’s important for crews to scout for these collapses before the drain tile is repaired and reburied. We won’t say that scouting for collapsed drain tile is the most exciting part of the job, but it certainly makes for a more cinematic experience!
Repair crews run a drain camera, or “snake,” down the broken end of the tile so that they can spot any collapses or other obstruction. The camera is exactly what it sounds like: thin, with hundreds of feet of cord that allows it to get deep into the tile.
There are two distinct right-of-ways on during a pipeline project. The “spoil” side of the trench is used to store all of the excavated topsoil and subsoil. The “drive” side is used for driving on, obviously. The tile is less likely to collapse on the spoil side, so crews run the camera about 50’ up the pipe. On the drive side, crews will run the video camera a full 100’.
The hope, of course, is that all the video (which is being reviewed live by the crewmember operating the video camera) comes back clean so the crew can bridge the drain, making the repair. Unfortunately, this is rarely the case. Tile repair crews very often need to replace all of the tile on the drive side, due to the weight of construction equipment that has been crossing it.
A 36” pipeline requires a trench that is 5’ wide. It’s easy to think that means only 5’ of drain tile to repair. The real figure could be as long as 105’, however.