Plowing with GPS

The NoDig SLM® 3.0 protective-layer pipes were supplied in dimensions OD 110 mm, OD 180 mm, and OD 225 mm – up to OD 180 mm as coiled goods, and in OD 225 mm as rod goods. Prior to the plow installation, the pipes had to be laid out along the route and welded using electrofusion couplers. The NoDig SLM® 3.0 drinking water pipes for the “Choustnik – Bohemian Chips” construction project, which were delivered as rod goods, were joined together using the heated tool butt welding process. After this step, the pipe ends were inserted into the feed device of the plowing equipment. Using coordinates read from the planning documents and imported into the plow computer, the lines could be installed with very high precision in terms of both position and height. This ensured that the correct position and a continuous gradient between the planned high points (vents) and low points (outlets) were maintained.

In addition, the current coordinates were documented every second, so that the actual position could finally be represented in the technical plans. This is an important component of the construction site measurement and the plan handover. Thanks to the coordinate-controlled plow installation, it was also possible to lay two pipe strings side-by-side at a precisely defined distance in several route sections of the “Jizery Part A” project. A good comparison of the space requirements and the speed of installation was provided by the sections that had to be realized using conventional open trench construction. With open trench installation, an average of approx. 50 m per day was achieved: the pipe trench was excavated, the line was laid in the trench, measured, and finally backfilled and the surface restored. With the controlled plowing process, an average of approx. 1,000 m per day could be installed and measured. The working width for plow installation was a maximum of 4 m – in contrast to at least 10 m for open trench installation.