During the weekend of 26 to 28 August 2022, the country’s best wrestlers will once again climb into the wrestling arena and knock the sawdust off their shoulders. The Swiss Wrestling and Alpine Festival (ESAF) in Pratteln is set to captivate the whole of Switzerland.
A Swissgrid extra-high-voltage line runs across the festival site in Pratteln. The current flows through this line at a voltage of 380,000 volts. It is an important element for ensuring a secure supply of energy to the Basel area. Swissgrid and the ESAF have taken the necessary measures to guarantee the safety of festival visitors at all times.
Safe events close to lines
As the operator of a critical infrastructure, Swissgrid is responsible for the operation, safety and maintenance of the extra-high-voltage grid. By carrying out regular maintenance work and around 12,000 inspections a year, Swissgrid ensures that lines are safe for people and the environment. Swissgrid’s grid infrastructure also meets the highest safety standards. To maintain a secure supply of energy, it is essential that electricity can flow without interruption as far as possible. This is because the disconnection of an extra-high-voltage line and the failure to reconnect it immediately weakens the transmission grid and therefore also jeopardises security of supply.
The safe operation of lines and systems is a top priority for Swissgrid. A certain number of safety regulations must be observed near extra-high-voltage lines.
Special security provisions therefore apply to events in the vicinity of extra-high-voltage lines where large numbers of people may gather. This ensures the safe operation of the line and the protection of people at all times. In particular, the provisions of the Ordinance on Electric Lines (LeV) and the Ordinance on Protection from Non-Ionising Radiation (NISV) must be complied with. In principle, «there must be no areas in the vicinity of extra-high-voltage overhead lines (...) where large crowds of people sometimes gather (assembly areas, markets, fairgrounds, recreation areas, sports grounds, camping grounds, public sunbathing areas, etc.)». The Federal Inspectorate for Heavy Current Installations (ESTI) may grant exceptions in justified cases. Due to the high security requirements set by ESTI and the associated additional costs for the organisers, Swissgrid recommends that no events are held in the vicinity of extra-high-voltage lines, but that alternative locations are selected.
The extra-high-voltage line at the festival site in Pratteln runs across electricity pylons at a height of about 26 m. The distance between the conductors and the ground in the middle between two electricity pylons is around 15 m. To ensure that the ESAF can take place safely, Swissgrid has obtained an exceptional permit from the ESTI and has defined extensive security measures, which the festival organisers have implemented.
- Protective fences and passageways
To prevent people from remaining in the area under the line, covered passageways will be installed to enable people to get from one side of the festival site to the other. The electricity pylons will be cordoned off with protective fences and signalled with warning signs and safety notices. Security personnel will ensure that people do not gather close to the line.
- Suspension points of the conductors doubly secured
The live conductors hang on insulator strings. These are mostly made of plastic and porcelain, with metal fittings. Twin supporting strings will be used to increase the safety of the line on and near the festival site – generally at crossings with roads, railway lines or close to residential areas.
- Earthing and protection against electric shocks
A comprehensive earthing concept has been drawn up in collaboration with specialist agencies. Lightning protection and protective equipotential bonding limit voltage differences on conductive, metallic parts that can be touched at the same time. These measures prevent the occurrence of dangerous contact voltages and guarantee the protection of persons from electrical systems.
Safe behaviour in the vicinity of lines
Anyone who stays, lives, works or pursues a hobby in the vicinity of extra-high-voltage lines must observe certain rules. In the worst case scenario, incorrect behaviour close to a line can lead to danger to life. In addition, every line that Swissgrid has to take out of service on an unplanned basis endangers security of supply. In order to draw attention to the potential dangers near lines, Swissgrid has set up a section on its website that contains comprehensive information material and lists the most important safety regulations.