I have done some hang gliding tether flying in Minnesota, Wisconsin and Texas.
Interestingly my wife Terry and I have learned that one person can hand hold the
tow/tether line if a pilot and glider are not climbing. Terry towed me up to about 250ft.- to 300ft. with the car at Padre Island, TX. The sea breeze at that altitude, on that day, was enough that I radioed down for her to stop the car because I no longer needed forward motion to maintain altitude.
I would estimate that Terry, by hand, had a force of about 15 to 20 lbs to maintain me at the same altitude.
We never measured this force but that is my best guess on how much tension must be on the line.
When water towing with a boat and having the glider up at a forty five degree angle a person could hand over hand pull the rope in if the glider was not climbing. If the pilot would push out on the control bar and start to climb it was no longer possible to hold the line with one hand or continue to hand over hand pull the tow line in.
Even though the wind that day was rope soarable at altitude the wind on the beach wasn’t enough to blow the glider away while sitting on the beach, into the wind, with the glider unrestrained.
At times while rope soaring the wind would diminish and the glider would start to settle. The pilot could do mild “S” turns to gain altitude and not have to radio the car to move forward.
For those that have water skied you know that if you turn left or right behind the boat you will accelerate. (Exactly the same principle - - only obviously different.
)
Depending on the sea breeze it could be possible to rope soar at Dockweiler and stay under the 60 feet
AGL restriction.
This maintaining force required with a towline (17 lbs) in conjunction with the wind allows you to ascertain how very small the added launching force needs to be to be of great assistance for a pilot.
Soft sand launches are much easier with a little help from your friend.