Czech Republic: GPS-controlled Ploughing

The SLM® 3.0 Protective Layer pipes were delivered in dimensions OD 110 mm, OD 180 mm and OD 225 mm — up to OD 180 mm as coiled bundles, and as rods for OD 225 mm. Prior to plough-assisted laying, the pipes had to be laid out along the marked pipe route and underwent electrofusion welding. The SLM® 3.0 drinking water pipes for the BV “Choustnik – Bohemian Chips” project, which had been supplied as rods, were connected using heating element butt welding. After this step, the pipe ends were inserted into the pipe-laying chute of the plough. Coordinates read out from the planning documents and recorded in the plough calculator enabled a very high degree of precision with regard to the location and installation depth of the laid pipelines. This measure allowed for strict adherence to the specified location as well the incline, which in turn ensured a continuous incline between the planned high points (air vent) and low points (outlets). In addition, the current coordinates were documented once per second, meaning that the plan indicated the actual location of the pipes — an important element of site measurement and the plan to be submitted. Coordinate controlled plough-assisted laying also made it possible to install two pipe strings parallel to each other at a precisely defined distance from each other in several segments of the marked out route of the “Jizery Part A” project. Those segments which needed to be realised applying conventional open-trench installation provided an excellent opportunity to compare the respective space requirements and laying speed. When applying open-trench installation, a mere 50 m per day (approx.) could be installed on average: Following excavation of the pipe trench, the pipeline was installed and measured in the trench, which ultimately was refilled and its surface area restored. With GPS-controlled plough-assisted laying, it became possible to lay and measure approx. 1,000 m per day on average. The required working width for plough-assisted laying was 4 m maximum — compared to a minimum of 10 m for open-trench installation.