A method and a device for releasing a tube during a rolling process in a three-roll rolling stand in case of an emergency. The roll holder cartridge (3) has a longitudinal open slot (10) at the yoke support of the vertical axis roll so as to remove the roll holder cartridge according to a direction coinciding with the horizontal axis of the yoke support of the vertical axis roll while the support remains anchored to the fixed structure in the stand of the roll mill. In case of routine maintenance, the cartridge (3) is pulled out laterally with the yoke support of the vertical axis roll anchored to the cartridge itself as the other roll supports.