A gripping device (76) is provided for lifting a preform for a wind turbine blade from a preform mould (71). The gripping device (76) comprises a base frame (62), a plurality of arms (78) slidably mounted on the base frame (62), each arm (78) having a proximal end and a distal end, a plurality of gripping members (86) for gripping a top surface (75) of the preform. The vertical position of one or more arms (78) of the gripping device (76) relative to the base frame (62) may change when lowering the gripping device (76) towards a preform to reflect the top surface (75) of the perform.