Prater’s Theory ramps up the tests, successfully displaying a method to build the pyramids, as one man comfortably moves 0.544-tonnes up this challenging 7.5° gradient.
7.5-degree Ramp Test – Real
After ironing out some issues with the equipment, such as reducing stretching by changing some synthetic ropes to natural fibre and lowering the rig, one man moved 0.272 kg / 0.272 tonnes up the 7.5-degree ramp.

In the second test, two men moved 0.544 kg / 0.544 tonnes, which is the same as one man moving 0.272 tonnes. Therefore, ten men would move a 2.5-tonne block up this relatively steep gradient.
Blocks would move up the pyramid faster than the 2-degree ramp, and the 7.5-degree spiral also benefits from using fewer materials in producing the ramps, rollers and rigs. Having fewer limestone casings needing to be cut back flush with the face is a huge advantage.
The number of builders required reduces dramatically, using a 7.5-degree pitch. The downfall, more men are needed to pull the same weight. But considering the test and the weight drawn up the ramp, a 30-tonne block would take 110 men and a 40-tonne block 147 men. This by utilising the spool’s large circumference, which has a diameter of 670 mm, and a small spool for moving blocks up ramps. The fixed axle is only 40 mm in diameter, and in one spool rotation, it travels 0.125 mm along the frame.
In the third test, the rope from the sledge was attached to the spool’s small circumference, which has a diameter of 220 mm. The draw rope was wrapped around the spools’ larger circumference, moving 0.544-tonnes up the ramp, which moved it up the ramp a lot easier than I expected.
This shows that a 2.5-tonne block would now take 5 men. Not bad for a 7.5-degree slope.

Over half a tonne, being held with one hand, also not bad.
I know from experience that one man could move more than 0.750 tonnes up the slope. But sticking with one man for 0.544-tonnes, which was the result from the test, would mean that it would take 55 men, to move a 30-tonne block. Seventy-four men, for a 40-tonne block, with 37 men on either side of the rollers. All based, on the garden model test.
As mentioned, the life-sized spool has a diameter of 670 mm, and the smaller circumference has a diameter of 220 mm.
If the spool had a diameter of 1.5 meters and used at the very top of the pyramid, 20 men would get a 15-tonne casing up the pyramid quite easily.

The spool’s in the image have a diameter of 3.5 meters, so by using larger spools, there’s a sizable amount of weight can be gained. And when you start connecting ropes from one spool to another, your looking at moving excessive weight, as tested. (Two Spools-Gearing the Pyramids)
Coming back to the 7.5-degree ramp, I was fortunate I selected this right from the start as one of the gradients. I knew moving a load up this gradient would be challenging, compared to a slope of less than 5-degrees and a good slope angle, making the tests worthwhile.
The tests went well, taking years to get to this point of being satisfied. Many small models were made, some got thrown to the side, and some were recycled.
As well as being delighted with the test and finding the gradient can reach the very top of the pyramid on the outside, the 7.5-degree spiral ramp also lines up with the great pyramid’s present-day blocks, showing this gradient can not be to far away from the slope used when built.
It’s nice to have a bit of luck than keep going back to the drawing board because something doesn’t work.
Bedroom Model Test-Using A-frame
In the small model test, dropping a weight of 3 drew 13 up the slope. The weight theoretically moving 13 tonnes up the 7.5-degree ramp. This equating to tonnes, 3-tonnes of pulling force, for 13-tonnes.

So, if 3-tonnes became 9.23-tonnes, this would theoretically draw 40-tonnes up a 7.5-degree ramp, involving 62 men. Again, thinking of the men and the lengthy duration of the project, I increased this to 100 men. That being 50 men, either side of the rollers.
The image on the page, Images Relevant Pages, shows the ramp has the room for the number of men required to move 30 and 40-tonne blocks to a reasonable height.