>Ropes used continually near their rated capacity will wear out quickly. Ropes under so much load as their capacity should have a very wide turning radius to reduce damage. >Ropes that are connected, knotted, or joined are especially susceptible to damage from a pulley.
>Tarring helps protect the ropes from friction wear when dragged over the ground.
The rope connections (slings) are not dragging on anything. The load pressure would make them taut, like a string on a guitar. Vary little sagging is taking place. That basically applies everywhere. If the ropes, (slings) are made up of many sections, and the groves in a dowel pin are deeper than the ropes thickness, there is no wear on the ropes, as they never touch the surface. It's the dowel pin makes contact, and not the ropes.
In hind sight, it doesn't matter how many barges carrying stones are on the Causeway, as long as there is an barge full of water to offset it's weight. Their distance apart could be very short. Remember, all the barges come to rest, once the movement has stopped. The system is balanced. As for skids making their way up the Pyramid face, they also come to rest, though much less so, than the barges on the 4.6 causeway. The stress on the ropes is with in spec, as the weight of the wooden vessel has been removed.
A good question to ask, is how many barges were there? The empty barges need to make the way back up the Nile, to be re-loaded with more stones, and return. Slid into place and attached.
When you think about it, it is really a beautiful system. You never need to unload stones down at the Harbor. They just continue to make their way up the Causeway. Khafre's Causeway has TWO raised platforms, which is required to make a Funicular system work.
For the most part, all the Pyramids have Causeway slanted at 4.6 degrees, and they all have two raised platforms. I personally, do not believe the Causeways were built for a religious purpose. They may have been used in a Religious ceremony, though they were not built for that reason.