The present invention relates to a blowing head for a blown cable installation process, comprising: a motor and a rotatable driving element operatively connected to the motor; a cable inlet to receive a cable to be installed; a cable outlet for connection to an installation duct into which the cable is to be installed, the cable outlet being connected to the cable inlet by a through bore, the through bore defming a cable path along which the cable passes in use; a buckle detector located between the driving element and the cable outlet, said buckle detector comprising a cavity, through which the cable path passes, within the blowing head, a sensor or sensors being provided to monitor, in use, the position of the cable within the cavity; characterized in that the buckle detector also comprising a deflector on which the cable impinges on its passage along the cable path, the deflector being arranged to introduce a bend into the path followed by the cable, the arrangement being such that, if the driving element propels the cable with an excess of force, the cable will preferentially buckle within the cavity at the site of the deflector.