A method and system are provided for automatically controlling tension of an armour tape being wrapped around a continuous strand of material, such as an electrical cable, travelling through an armouring machine having a reel of tape and tape feed rolls rotating around the strand and having a motor or suitable variable speed drive (such as a P.I.V. variable speed drive) for controlling the speed of rotation of the tape feed rolls and thus of tape feed rate. To achieve automatic control, the diameter of the strand entering the machine is measured, preferably by a laser, and the diameter of the armour over the strand exiting the machine is also measured, also preferably by a laser. The measurements are communicated to a computer which compares them to preset values. The computer drives the motor or variable speed drive and adjusts them when required depending on the measurements of the two diameters and so as to maintain the preset values during the wrapping operation.