Trenchless pipe laying for water and wastewater

Water pipes, sewage pipes and other utility lines form part of the invisible foundations of a functioning infrastructure. However, particularly in rural areas, when developing new areas or renovating existing networks, the same question arises time and again: how can large pipes be laid quickly, economically and with as little ground disturbance as possible?

At the bauma, Foeck is showcasing a system that addresses precisely this issue. Instead of excavating a wide trench, the ground is cut open using a laying blade. The pipe is ploughed in in a single pass, and the ground is then closed up again. The technology is primarily aimed at projects to supply villages and towns with water, as well as at waste disposal via sewerage systems.

Foeck relies on ploughing technology instead of traditional pipe trenching

The basic principle differs significantly from conventional civil engineering. In traditional laying, a trench is first dug, often secured, and then backfilled. This involves considerable earthworks, particularly with large pipe diameters and deeper pipes. The ploughing technique works differently. A winch vehicle pulls the laying unit through the ground with great force. The laying blade cuts and splits the soil, forming a channel and guiding the pipe directly into the resulting opening. This eliminates the need for extensive excavation of the ground. This difference can be particularly significant over longer distances. The soil is not completely excavated, but merely cut open and pushed to the side. As a result, the soil structure is largely preserved, and there is significantly less mixing of the soil layers.

Installation blade forms the channel for large pipes

The heart of the system is the installation blade with blade shoe. It creates the necessary space in the ground and forms the channel for the pipe. In the example shown, the pipe has an outer diameter of around 45 centimetres. The ground is opened up to around 50 centimetres for this. If such a pipe were laid in the traditional way at a depth of around two metres, the trench would have to be significantly wider. Depending on the ground conditions, safety measures would be necessary to ensure that workers could work in the trench without risk. Trench widths of six to seven metres are being discussed. The difference compared to the narrow plough channel is correspondingly large.

Key features of the installation technique presented:

• minimal-trench laying of water and sewer pipes
• ploughing the pipe into the ground in a single pass
• laying blade for cutting and shaping the soil
• minimal soil disturbance compared to open-cut trenching
• laying of large pipe diameters up to 63 centimetres to date
• significantly higher daily progress than with conventional excavator work

Faster pipe laying with lower fuel consumption

The key advantage lies in speed. Depending on the project, installation is said to be 10 to 20 times faster than conventional excavation work. A daily progress of up to four kilometres is cited as a possibility. For infrastructure projects where long routes need to be constructed in a short time, this is a significant factor. The increased speed also has an impact on fuel consumption. When less soil needs to be moved, loaded and reinstated, machine usage drops significantly. Foeck estimates this to be around one-tenth of the consumption compared to conventional excavator work. These figures make the method particularly attractive where long pipelines are routed through open spaces, agricultural areas or less densely built-up regions. The impact on the environment is minimised, and the construction site moves on more quickly.

Infrastructure for water, wastewater and new developments

The technology is particularly suitable for supply and disposal pipelines. In many countries, there remains a great need for rapid infrastructure development: water pipes need to be re-laid, wastewater networks expanded or existing systems renewed. In such projects, it is not only technical feasibility that matters, but also the construction time. Every week the construction site is shortened can reduce costs, simplify approval processes and minimise disruption to residents, agriculture or traffic. The ploughing technique can therefore be an important tool, particularly for rural regions. Water and wastewater often need to be routed over long distances, whilst open trenches would incur high costs and cause significant disruption.

Minimal-trench methods are gaining importance in civil engineering

The solution presented here demonstrates the extent to which pipeline construction is changing. Traditional civil engineering remains indispensable, but not every pipeline necessarily has to be laid in an open trench. Minimal-trench methods are gaining importance where speed, soil protection and cost-effectiveness are paramount. For clients, the combination of high daily output and reduced earthworks is particularly attractive. Less excavation means less transport, less backfilling and faster surface restoration. Foeck is thus positioning the system in a sector that is likely to grow further as a result of the global expansion of infrastructure. Water, wastewater and security of supply remain key priorities. Methods that can lay pipes more quickly and with less disruption are therefore becoming increasingly important – not as a replacement for every traditional construction site, but as an efficient alternative for suitable routes.