Towrope tensions....Part II

On Monday, October 15, 2018 at 2:33:35 PM UTC-4, Retting wrote:
Well, I said ‘during tow’ thinking that would cover beginning to end. I need to determine the attachment strength for a tow hook on a towplane.
What might rope tension be from initial roll in grass (thinking start will be highest). I thought maybe testing was done years back and a chart or data existed.
Years ago back when I was teaching at Schweizer, the topic came up and less than 300#, towing the 2-32, 3 adults, behind a 180 Supercub was agreed by Paul and a couple of engineer types. I took it as gospel, but have wondered over the years how close they were.
Now I am really curious.
My previous thread got off track into formulas, winch launching, and pitch angles.
The info provided so far seems encouraging. I thought it might be higher.

R

The tow rope (or weak link) are supposed to be able to withstand between 0.8 and 2 times the weight of the glider. What's the point of ensuring that if the attachment to the towplane is built for less than that, e.g., 300 pounds? Why not build that tow hook to handle 2x the flying weight of the heaviest glider you will tow?