Re: Topping lift loads?
The following is a sceniaro where a strong topping lift might be a good idea.
Your sail is down, the mail halyard is at the mast and you are motoring and run aground.
You let three or four of your heaviest crew hang on the boom as you swing it outboard as you try to heel the boat enough for the keel to clear the mud to get free.
A 1,000 pounds maybe.
I always think of the topping lift as an emergency halyard anyway.
But in truth on most smaller boat most lines are sized for hand comfort rather than for strength.
The lesson from the Icarus story is not about human failing.
It is a lesson about the limitations of wax as an adhesive.
If you have an engineering problem solve it.