> I'm picturing what is in the diagram, which maybe
> I'm taking too literally. It appears as a stone
> roller that doesn't turn. Even if you used a good
> modern climbing rope that can lift an entire
> truck, and has an additional mantle over the core
> strands for protection, it wouldn't last a day if
> you were lifting a 200lb person, because all the
> force is focused on that one rubbing point and
> would wear the rope away.
> Rope isn't designed for abrasion when you
> calculate its tension strength. If you calculate
> the rope strength necessary for lifting huge
> blocks, then you might as well double its
> thickness, if it has a rubbing point like in the
> diagram, and it will still fail after probably
> less than 20 uses.
> Just saying. You can't cheat in the model.
> Gravity and friction gets you every time.
I don't believe they used a pulley that changed rope directions by more than about 50 degrees. This is not very stressful for rope if the friction of the pulley is low and the radius is high. Rope wear is caused by excessive bending under load, slippage and the variability of the inside and outside diameters on the pulley. Most ropes can stretch and unstretch quite a few times before losing significant strength though obviously this does cause internal wear and tear.
I believe they called their "pulleys" dm-sceptres and they were probably actual pulleys that redirected the ropes at the pyramid edges allowing stones to be pulled straight up the sides. There are numerous means they could have designed these devices and they could be as simple as a curved stone with a large radius or more complex like a roller sitting in a trough with the rope passing over it. Anything that tuned as the rope was redirected could be made so there was very minimal friction and very minimal rope damage. Even in the complex small diameter block and tackles common in the 19th century rope wasn't replaced every day or every week. Modern cranes use block and tackles and the rope will last years if properly used and inspected. Broken ropes are far more common than worn ropes and broken ropes are very rarely the result of wear; they result from misuse and abuse. I once saw an Osha report that said more than 90% of rope failures resulting in fatalities were caused by abuse and were not properly inspected after incidents.
It's simply far easier to make a rope and pull a stone up the side of the pyramid than it is to make a ramp and pull them along it. This is the bottom line. You can make lots of rope and do it the easy way or conscript tens of thousands of men and do it the hard way. In light of the physical evidence we can say they did do it the easy way. They let the men stay at home and made a lot of rope. This saved huge costs in logistics and planning. It's far easier to make systems to accommodate a thousand men than 100,000. One rope could lift at least thousands of stones if it were were not abused. It would simply have to be pulled from service if it were damaged. I would propose that these people paid far more homage to "ptah" than modern people do. We damage tools and then continue using them but ancient people were far more concerned about craftsmanship than we. The little workers cemeteries and few broken bones proves their safety program mustta been superior to our's. Individuals were responsible for results.
I can only imagine how huge the cemeteries would be if the were dragging stones in these oven-like conditions or if they were careless on ramps. It wouldda been a veritable bloodbath.