Abstract: Optical fibre cable laying apparatus comprising a mobile carrier for paying out cable from a reel and laying the cable in a trench formed by a tyne on the carrier. The reel is rotated, to effect paying out, in a fashion such as to control the tension in the cable. A slack loop is formed in the cable during paying out and the amount of cable in that slack loop is monitored. When the amount of cable in the slack loop decreases, the rate of paying out is increased, and when there is a greater amount of cable in the slack loop, the rate of paying out is decreased. Tension rollers are employed to further minimize tension in the cable as laid.