a rodless cylinder rope tensioning apparatus maintains tension in an endless rope operable for threading a web in a paper - making apparatus and includes at least one rodless cylinder having at least one yoke sheave attached to the internal piston in the rodless cylinder . the rope is initially threaded around an entry guide roller and the yoke sheave and spliced , and then stretched by operation of the rodless cylinder , which selectively causes the piston to relocate the yoke sheave along the length of the rodless cylinder and apply a selected degree of tension to the rope . in a preferred embodiment a pair of entry guide rollers is provided in a frame containing a pair of parallel rodless cylinders , each having a yoke sheave independently movable along the rodless cylinder by operation of the rodless cylinder piston , to effect tensioning of a pair of ropes in the paper - making apparatus . various air - operated control devices are provided to effect initial threading of the rope on the entry guide roller and yoke sheave , as well as the desired “ run ”, “ paper threading ” and safety operations of the rodless cylinder rope tensioning apparatus .