Re: Forces on a dockline while docking....
it seems to me the manuever is not only about absorbing motion (energy) into the rope (creating friction and heat) but about changing it's direction. By using the rope as a pivot, it not only absorbs a lot of the boats momentium, but because it is redirecting it, increases the friction on the hull from the water itself.
It's all very simple and elegant really.
you could probably do the same with a rope pretied off to bow and stern cleats and a waiting (high strength) hook attached to the piling in some fashion. As you sail by, clip in to the hook and let it do the work
In the end all that matters is how fully you loved, how gently you lived, and how gracefully you let go of things that did not belong to you -buddha