a tensioner for deploying a member such as a pipe or cable , such as a sub - sea cable deployed from a ship , comprises an endless track and drive means for driving the track . the track includes a plurality of traction elements mounted thereon for movement with the track . each traction element includes one or more cushions for supporting the member , and a pair of opposed arms mounted on respective sides of the base of the traction element . one or more of the arms is pivotally mounted for movement between a clamping position and a release position . in an alternative arrangement , four moveable arms are linked in diametrically opposite pairs to move between a release position and a clamping position . cushions on the arms clamp the member in conjunction with the cushions of the traction element , when the arms are in the clamping position . guide means are provided to urge the arms into the clamping position to grip the member as it passes through the tensioner .