Towline Tension

EdbrazilEdbrazil Posts: 1,289 Historical Baller
edited December 3 in Other Stuff
Anyone out there have some information to contribute, about how much towline tension a SL skier generates?
Some years back, Dave Benzel had a computer-interfaced system, that measured tension and other factors.
I did some work at times with a Dillon Force Gage. Eay back, Jim Sylvester (AWSA President, Technical Committee)
did some measurements in the 1960s.

I have heard a figure in the range of 900 lbs. max. Don't know if this is accurate; sounds like a lot.

Comments

  • A_BA_B Posts: 3,779 Mega Baller
    That system was called LISA and there was an article in Spray or WSM. 900 was the max that Andy put on the line at 39 Off right behind the boat. The plotted pull force started with deepwater starts, which also put a fair amount of load on the line.

    I am only guessing, maybe 250-300 pounds if I am remembering right. One thing that stood out was how consistently Andy peaked and where he peaked compared to some other decent non-Pro tournament skiers. There was quite an increase as all skiers headed into the wakes.

    I wanted to get a copy of that article but WSM doesn’t have back issues, and had posted the approximate date of the article before, requesting all those guys who still have stacks of old magazines to look for it.

    The only magazine I had was one where Benzel ski school was advertising to “come ski with LISA”. Not the article.

    I’d love to see the article if any Ballers can post a copy.
  • ALPJrALPJr Posts: 1,326 Crazy Baller
    I think Syderhoud measured the lbs of pressure on the rope in the West Coast Slalom video with Marcus Brown and Terry Winter.
    Dacon62
  • 6balls6balls Posts: 4,496 ★★★Triple Panda Award Recipient ★★★
    In college when I was stronger and skied even more improperly than I do now I used to go through about 3 straightline brand ropes/year that were tensile rated at something like 1000-1200 lbs.

    Always carried a new one in my trunk in case I skied with friends so I could give them a rope after (often) breaking theirs. Broke two in one day once and broke one at collegiate regionals. When I was a kid @razorskier1 broke three in one day--the one we were using, our spare, and the one we bought at the marina that day cuz we were out of ropes.

    My guess is with all the understanding of efficiency now the amount of line tension on top skiers may be less than before? Dunno, in any case I bet it's still a very big number.




    Dave Ross--die cancer die
  • eleeskieleeski Posts: 3,063 MM Trick Skier / Eccentric Person
    If I remember right (it was back in college - a LONG time ago), just riding a trick ski was about 75 pounds pull, the smoothest O was 150 and a sideslide was 25 pounds. Any wake trick or hard pull went off scale on our 500 pound max scale.

    Remember the Saf-T-Pop automatic trick release? With such wide variations in load, no wonder it didn't work.

    @6balls Ropes are much better nowadays. You braggart. (I'm still impressed.)

    Eric
    6balls
  • pregompregom Posts: 73 Baller
    I'd like to see visualizations of the pull force through a pass in the course. Maybe something like this GIFwith the rope that changes color as the load gets higher? Or a 3D plot where the x- and y- axis represent the handle path and the z-axis represents the load? and all this with real data coming from different skiers?
  • AdamCordAdamCord Posts: 484 Open or 55K Rated Skier
  • JordanJordan Posts: 851 ★★★Triple Panda Award Recipient ★★★
    Wondering if modern skis are more efficient at turning resistance to the boat into acceleration and therefore reduce tension on the rope?
    6balls
  • mwetskiermwetskier Posts: 1,209 Crazy Baller
    buy borrow or steal a copy of suyderhouds ' west coast style ' instructional video. theres an entire section on video analysis of terry winter and marcus brown skiing shortline and some of the clips have a time readout and strain gauge window that give real time values of elapsed time and rope loads. that may very well be some of the most accurate and reliable data you will ever find on the subject.


  • taptap Posts: 56 Baller
    edited December 4
    I've measured skiers anywhere from 400 to 700 lbs. force across a pretty good range of skill level. In general, the better the skier the smoother and higher the load.

    Some previously posted data.

    6ballsWishpregom
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