Fig. 1 'Sekifu-no-kai' group successfully trys to roll up a big log with 'Kake-nawa'. You can roll up anything saving more than 50% force, at any upward slope with two or more ropes.
You can see scientific basis here (Written in Japanese).
'Kake-nawa' (Rolling over with ropes)
Fig. 1 'Sekifu-no-kai' group successfully trys to roll up a big log with 'Kake-nawa'. You can roll up anything saving more than 50% force, at any upward slope with two or more ropes.
You can see scientific basis here (Written in Japanese).
Ancient people were clever enough to find out suitable method to roll any shaped stones upward, such as adapting logs beside a cubic stone or covering the stone with carpet-like materials.
Fig. 2 A block with 4 logs was easily rolled upon upward sloping land of 50 degree angle.
'Nawa-teko' （Leverage with a rope)
Fig. 3 A granite plate(60kg) is easily moved by leverage with a rope.
Fig. 4 A granite plate(70kg) is easily moved by leverage with a rope.
'Action point' of Nawa-teko was found to be invisible. 'The invisible action point' is revealed to be the intersection point of vertical line from the force point and horizon line from the fulcrum.
Fig 5 'Action point' is different from that of normal leverage.
Angle of lever interlocks to the point of action in 'Nawa-teko'（Leverage with a rope）.
If the length of 'point of action' to 'point of pivot' is very short comparing with the length of 'point of effort' to 'point of pivot', you can save force to pull the rope.
Ladder or Y-shaped-log shown in figures were used as a lever with a rope or ropes. Two Y-shaped logs in Fig 1 were replicas of those found at Jomon-ruin of Sakura-machi Oyabe-city, Toyama, Japan in 1997(length of them are ca 1.5 m and weighted ca 150kg). A true usage of them were not known. But Jomon people used handy sized ropes and levers as tools as powerful carrying tools. Jomon people must have a feeling of supernatural power to a rope. And they made a pattern of ropes to their pottery, I imagine.