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Estimating actual pulling tensions of a steel rope using a PTO winch

  1. Oct 7, 2014 #1
    I am an electrician pulling underground power cables through concrete ducts.

    We have had issues using a rope tugger and 7/8 double braided rope as seen here

    It keeps getting stuck before certain bends in the duct towards the end when the rope is at its tightest and is pulling the most weight. The friction between the rope and duct must be amazing.

    I believe it has to do with how the rope stretches under tension and the number of bends in the run. This wasnt a well engineered job and we are only a sub trade. So we have no choice but to try all angles.

    We are about to bring out a truck with PTO and 30 tonne winch. I believe this will offer us the advantage of slow smooth power and almost no stretch in the line. This should in theory reduce the chances of the nose getting stuck (http://s4d8b89f6c462f.img.gostorego.com/809E82/cdn/media/s4d8b89f6c462f/HDD_Drilling_Parts/HDD_Swivels_and_Pullies/multiple-pulling-harnesses-collage.jpg [Broken]

    I am trying to calculate what the winch will output in terms of pulling force at a given rpm. (say idle to start)
    This would allow me to know when I am applying to much power, see with a rope and tugger you can tell when something is wrong. Tension will slowly build and will show on the unit. It has a gauge. The truck just pulls like a ox and could really do some damage if we don't have some means of knowing what its putting out.

    Any help would be greatly appreciated

    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Oct 7, 2014 #2
    I know i accidentally posted this twice, please delete one of them
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