A device for tensioning chains on crawler-type or tracked vehicles, in particular the chains of hydraulic excavators, comprises a first cylinder arranged in an area of the chassis for the tracked vehicle, and operatively connected via a piston rod to a guide wheel to tension the chain. A second cylinder forms a spring cylinder and is operatively connected to the first cylinder. The second cylinder concentrically encloses the first cylinder to form a double cylinder and each cylinder is provided with a separate hydraulic connection. At startup of the tracked vehicle, the hydraulic connections of the double cylinder are admitted with a specifiable pre-tensioning pressure. The spring cylinder can be moved with maximum spring travel to its end position because of its larger cross-sectional surface, and the tensioning cylinder pre-tensions the chain with a force that corresponds to the pre-tensioning pressure.