Methods and devices for placing multiple strand cables under tension

A method for placing a multiple-strand cable under tension by successively tightening individual strands of the multi-strand cable by using a single tensioning jack, the jack being capable of tightening individual strands of the cable to a selected tension, said method comprising the steps of:

• tightening a first strand of the cable with the jack to a selected tension, the first strand being arranged such that its tension can be measured,
• tightening a second strand of the cable with the jack, thereby simultaneously decreasing the tension of the first strand, while measuring the tension on the first strand until tension on the second strand is equal to the measured tension on the first strand,
• anchoring the second strand,
• tightening a third strand of the cable with the jack, thereby simultaneously decreasing the tension of the first and second strands, while measuring the tension on the first strand until tension on the third strand is equal to the measured tension on the first strand, the tension on the second strand thereby also being equal to the tension of the first and third strands,
• anchoring the third strand,
• tightening and anchoring all remaining strands using the same procedure used to tighten and anchor the second and third strands to thereby place all strands under equal tension,
• measuring the final tension of the first strand, releasing the first strand, re-tightening the first strand with the jack to the measured final tension and anchoring the first strand thus tightened.