Soil investigations for 380 kV new construction line Helmstedt/East – Wolmirstedt:
50Hertz Transmission GmbH (50 Hertz) and TenneT TSO GmbH (TenneT) are planning the construction of a new 380 kV overhead line from Wolmirstedt via the Helmstedt Ost substation to Salzgitter. The project is part of the “Wolmirstedt-Helmstedt Ost – Wahle extra-high-voltage line; three-phase nominal voltage 380 kV” project.
In preparation for the planning and construction of the 50Hertz grid expansion project, subsoil investigations are required in Wolmirstedt. These are expected to take place between 28.04. and 23.06.2025. The timing of the measures depends on external circumstances, such as local conditions as well as soil and weather conditions.
The project is planned as an overhead line. The purpose of the ground investigations is to obtain precise knowledge of the ground conditions for the erection of the pylons. For the subsoil investigations, it is necessary for the employees of the companies commissioned by 50Hertz to enter/drive on the land and use agricultural and forestry roads.
In addition, it may also be necessary to use areas temporarily, for example to park the necessary equipment, vehicles, tools and materials and to transport them to and from the site. It may also be necessary to set up temporary markers for staking out exploration points in the terrain. It must be ensured that access to the drilling points takes place via the shortest route or with the least disruption and impact for the owner(s) or manager(s) and other tenants.
During the measures, 50Hertz and the commissioned companies will take care to minimize any adverse effects on the affected properties. If, despite all caution, there is damage to the substance (e.g. damage to land or vegetation), 50Hertz will compensate for this damage caused directly by the ground investigations in accordance with the statutory provisions of Section 44 (3) EnWG. 50Hertz shall compensate ground damage in accordance with the current compensation rates as determined and published by the respective state farmers’ associations, for example. If no agreement can be reached on the compensation of land and/or vegetation damage, a publicly appointed and sworn expert can be commissioned to determine the amount of damage. The costs for this shall be borne by 50Hertz. If no agreement can be reached on monetary compensation, the competent authority under state law shall determine the compensation at the request of the project sponsor or the entitled party.
In order to be able to carry out a groundwater and soil investigation, exploration and drilling measures must be carried out. It is intended that the following exploration and drilling methods and equipment will be used: Heavy dynamic probing, pile-driving core probing, borehole probing, pressure probing and rotary core drilling with a diameter of approx. 100 to 300 mm, reaching depths of up to 15 meters.
The drillings are carried out with a combined piling and rotary drilling rig with rubber crawler tracks, total weight approx. 9.5 tons, length approx. 7.0 meters, width approx. 1.5 meters, height approx. 2.6 meters in driving mode, approx. 6.8 meters in drilling mode. For the pile-driving and pile-driving core drilling, the use of a crawler drill with rubber track chassis as carrier equipment, with a total weight of approx. 1 ton and external dimensions of approx. 2.50 meters by 1.1 meters with a height of approx. 1.5 meters in driving mode and 3.0 meters in working mode, is planned. Any necessary borehole probing will be carried out with a mobile excavator.
A probing device with chain drive is used for pressure probing. The required working area for the device is approx. 16 square meters. The device weighs approx. 21 tons and is up to 3.5 meters high. All boreholes and exploratory holes are backfilled with clay pellets immediately after completion of the exploration, unless they are converted into a groundwater monitoring well. All exploration work is supported by an escort vehicle (Unimog, PickUp, etc.).
The parcels of land affected by the ground investigations are as follows:
(Note: Exploratory work is being carried out on the parcels marked with an x).
District: Farsleben | Parcel: 3 | Parcels: 854x, 685/12x, 690/12x
District: Mose| Parcel: 9 | Parcels: 7x, 9x, 46x, 47x, 50, 52x, 56, 57x