Munich, 17 June 2025 – An effective network infrastructure is essential for Germany. High-performance, functioning networks for electricity, water, gas, district heating and the internet are just as crucial to the growth, competitiveness and future prospects of national economies as roads and bridges.

According to the German government, these infrastructures are essential for the further development of the European single market as well as for strengthening Germany as a business location. By promoting better networking, the aim is to increase energy security, drive forward the integration of renewable energies and improve digital connectivity. Overall, the German government considers the modernisation and expansion of this infrastructure to be crucial for economic development and the achievement of climate targets.

One example of the market significance of this is the expansion of the electricity grid. According to the monitoring report of the Federal Network Agency, the expansion projects in the electricity grid totalled 16,832 kilometres as of 31 December 2024. Of this, only 3,234 kilometres had been completed by the turn of the year.

Modern pipeline construction increasingly uses technologies that improve efficiency and sustainability. The most significant developments include trenchless laying techniques as well as digital tools and software solutions. These help to make pipeline construction future-proof and meet the increasing demands for quality, sustainability and cost-effectiveness. In this context, the Cologne-based Rohrleitungsbauverband e. V. (rbv) emphasises the central importance of Building Information Modelling (BIM) and Lean Construction for pipeline construction. BIM enables optimised planning, execution and management of structures through the digital modelling of all relevant data. Lean methods also promote networking and exchange between all those involved in construction, leading to more efficient and transparent collaboration. Overall, the rbv sees BIM and Lean Construction methods as two key technologies that make pipeline construction more efficient, transparent and sustainable.

PORR – a pioneer in Building Information Modelling (BIM)

The importance of Building Information Modelling (BIM) was recognised early on, and this method is considered a pioneer in the digitalisation of the construction industry. It was used in classic building construction projects in the early stages of BIM development. Today, BIM is also used in tunnelling, structural engineering and special civil engineering – especially in large infrastructure projects – as well as in pipeline construction for planning and construction.

Construction of network infrastructures: potential and high requirements

In recent years, PORR has already completed a large number of projects related to pipeline construction. The prestigious ‘SuedLink’ infrastructure project, which is being carried out by network operators TenneT and TransnetBW, will cost a total of around ten billion euros and will transport energy from wind farms in northern Germany to southern Germany via two high-voltage direct current transmission lines over a distance of around 700 kilometres.

In return, solar power will be transmitted from southern to northern Germany. PORR is involved in a consortium working on one of the most challenging sections of the project – the crossing of the Elbe (ElbX).

The cables will be laid in a 5.2-kilometre-long tunnel at a depth of 20 metres below the Elbe from Wewelsfleth in Schleswig-Holstein to Wischhafen in Lower Saxony. The work will draw on the expertise and experience of various specialists. In January 2025, divers were even deployed during the construction of the underwater concrete base to ensure quality and safety. The construction pits for the tunnel shafts will be watertight and stable, even though both the start and end shafts are below the groundwater level. An essential part of this work is the use of diaphragm walls in special civil engineering. Diaphragm walls have a static and/or sealing function and are suitable as retaining walls, cut-off walls or foundation elements. They are constructed as reinforced concrete walls and are considered virtually impermeable to water. Excavation is carried out by cable excavators with diaphragm wall grabs using a supporting fluid. This technology enables a stable and watertight construction pit that meets the requirements of the project.

Ultranet: Efficient and sustainable energy transmission

Ultranet, a power line construction project by network operators Amprion and TransnetBW, comprises a 340-kilometre-long HVDC line from Osterath in North Rhine-Westphalia to Philippsburg in Baden-Württemberg. Here, too, surplus wind power from northern Germany is to be transported to the south with minimal losses in order to secure the energy supply there. Ultranet is scheduled to go into operation in 2026. PORR has been awarded the contract for the deep foundations for 36 new pylons for a section of this power line. A total of 144 bored piles with diameters of 1,200 mm for 31 pylons and 1,500 mm for five pylons were constructed. In addition to the limited space available, the difficult logistics at several locations also proved to be a major challenge. For environmental protection reasons and to protect the soil and groundwater, only bio-oil was used in the hydraulic hoses.

Open trench construction for SuedOstLink: on schedule with Lean Construction

The SuedOstLink is another major infrastructure project in Germany that aims to transport electricity from wind-rich regions in the north to the energy-hungry south. It is an HVDC line that runs for approximately 540 kilometres from Wolmirstedt near Magdeburg (Saxony-Anhalt) to the former Isar power plant site near Landshut in Bavaria. The project comprises two direct current connections, each with a capacity of 2,000 megawatts and a voltage of 525 kilovolts. These connections will mainly be laid as underground cables to minimise the impact on the environment and increase reliability.

The first 18 kilometres of section A1 will be constructed as overhead lines. For the subsequent 29.6 kilometres, PORR has been commissioned with laying the protective pipes in open trenches, constructing crossing structures as well as creating access roads and work areas. As two 525-kilovolt direct current connections are being laid for the SuedOstLink, separate cable trenches are required. To ensure efficient workflows, the project is being implemented using the Lean Construction method in a phased construction process. The work along the cable route is being carried out by several synchronised work teams. Due to the high demands on soil quality, a separate soil management concept is being implemented. This includes processes such as soil removal, soil treatment in a mobile mixing plant, testing of the soil material and reinstallation. The goal: minimal environmental impact.

The projects mentioned are not only technically demanding, but also of great strategic importance for national and European infrastructure. They make a decisive contribution to securing energy supply, integrating renewable energies and digitalisation. The ongoing development and adaptation of these infrastructure projects are crucial for economic development and underline the key role that PORR plays in the construction industry.