First surveys for railway tunnels on the new Dresden-Prague line
Germany‘s longest railway tunnel is to be built across the Ore Mountains to better connect the metropolises of Dresden and Prague. In order to find the ideal tunnel alignment, Deutsche Bahn AG (DB) is now conducting its second drilling campaign.
Initial results for possible tunnel routings have already been deduced from earth drillings in the Ore Mountains. DB project manager Kay Müller emphasised the importance of progress in the project for the ecological transport turnaround. In future, there should be much faster and more frequent passenger and freight trains between Dresden and Prague. They would then link the metropolises in just an hour, and it should become possible to relieve the much frequented Elbe valley.
The first exploratory drillings evaluated
Before the tunnel itself can be planned, geological test-drilling has to be carried out in the Ore Mountains. DB has been carrying out such measurements and drilling since 2020. The first boreholes to examine the geological formations reached down to a depth of 400 metres below ground. In total, around 130 boreholes were examined at nine points. In the Central Saxon Mountains, the soil and rock samples taken are of good rock quality. Only very few adverse factors were found, and on the basis of these findings it is expected that the tunnel could be built without any major difficulties. In the Gottleuba valley, on the other hand, several fractures and irregularities in the rock structure were found, and these will have to be taken into account for tunnel alignment planning. The structure in the Börnersdorf area was also examined in detail; however, it is not yet possible to determine an alignment from the current findings. In the second drilling campaign, from November 2021 to May 2023, 14 up to 500 metre deep boreholes are expected to be drilled.
The Dresden-Prague upgrading project is currently in the early planning phase. DB has worked out several possible variants for the future layout of the additional and adapted tracks in Heidenau. The options to build part of the section in a tunnel with the other part above ground as well as a continuous tunnel are being investigated. The aim is to identify a so-called preferred variant. “This must be compatible with the entire region and the environment and also take into account economic and regulatory approval aspects. In addition, the solution must comply with the specifications and criteria of the German Federal Government,” said a railway spokesperson. “The decision for the preferred variant will only be made at the end of the preliminary planning process, probably in 2024.”
New Dresden-Prague line
The rail link between Dresden and Prague is part of the trans-European Orient / East-Mediterranean corridor. It connects the German North and Baltic Sea ports with the economic centres in south-eastern Europe and passes through nine member states of the European Union. The route is of strategic importance for freight transport. The necessary cross-border tunnel through the Ore Mountains will be at least 25 kilometres long, 15 kilometres of which will be on the German side, making it the longest railway tunnel in Germany.