부산대학교 도서관

In mobile laying apparatus for laying an elongated element, such as a cable, in a trench, especially a trench in a sea bed, which apparatus is advanced in a predetermined direction and includes apparatus for digging the trench and ways along which the element slides as it is deposited in the trench, tension control apparatus and a method for preventing the accumulation of such element upstream of the laying apparatus as the element is laid. In the method, a tension force is applied to the element so that the tension thereon upstream of the laying apparatus is at least equal to the tension on the element downstream of the laying apparatus. The tension control apparatus includes motor driven rollers or tracks at the ways which engage the element. The torque which the driving motors apply or alternatively, the energization of the driving motors and the advance of the laying apparatus is controlled by the position of a portion of the element upstream of the laying apparatus.