Quote:
Originally Posted by BlackSash
Dumb question,
would a given floor be tightened all at once, one side and then the other, the middle to the outside, does it even matter?
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It does matter a great deal and is one of the major considerations contemplated by the designers. As you note, it can be done from one end or the other, or both. It is not done from the middle - you need to have room at the end at the section to install clamps, jacks, gauges, etc.
There would also be a sequence of tensioning that is followed rigourously - i.e. left-to-right, alternating sides, centre-outward, etc.
The reason for tensioning on alternating ends is that the cable will experience a level of friction (also called a loss) inside the sheath which varies according to distance from the jack, the type of sheath, the "wobble", the number and degree of curves present in the profile, the lubricant used, etc. By alternating the jacking side, the losses are the same at each edge rather than having one side outperforming the other. The alternative is to simultaneously jack both ends, but this may not prove to be economical or practical.