A harness retractor (62) for a harness system (60) of a child safety harness, which has a tensioning web (80) and buckle connectors (70) coupled to straps of the safety harness. The tensioning device has a rotatable retractor mechanism (90) connected to the tensioning web (80) and biased to wind up the tensioning web in a wind up rotation direction. The tensioning device has a locking device (110) biased to a first position preventing rotation of the retractor mechanism in the wind up direction. The tensioning device has a buckle housing (64) coupled to the retractor mechanism. The buckle connectors (70) are releasably connectable to the buckle housing (64). A release mechanism is connected between the locking device (110) and the buckle housing (64) and can switch the locking device from the first position to a second position permitting rotation of the retractor mechanism in the wind up direction.