When work needs to be carried out on high-voltage installations, the installation must first be disconnected and then connected to the ground; the workplace is grounded.

On electrified railway sections, one rail (the S-rail) is always continuously grounded. It serves as one pole in the overhead line system. The disconnected part of the installation is connected to the S-rail using the grounding tool. This ensures that it is guaranteed to be safe, both from atmospheric charging and from incorrect voltage connection.

Only an electrical safety officer is allowed to carry out the disconnection and grounding of a part of the installation. To become an electrical safety officer, one must have extensive experience working on electrical installations and have undergone special training.

The electrical safety officer requests disconnection of the line from the traction power controller. They monitor the lines within a larger area and can therefore determine if the line can be disconnected without negative consequences.

Caption: This is how the grounding tool was used.