What should you remember before you go about pushing tram carriages damaged due to a collision?

In a tram car damaged as a result of a collision, the brakes (especially the parking brake or track brake) may be locked to immobilise the vehicle. To enable the safe and effective pushing of the tram set, these brakes must first be mechanically released using release mechanisms. Attempting to push the tram car with locked wheels would be ineffective and could lead to further, serious damage to the rolling stock and the track.