The friction you have to overcome is exactly the same as dragging. To achieve a slope of 1 in 15 you have to get the coefficient of friction down to around 6%. If you can do that you could just lay your track flat on the ground and drag the stone along it. You would only need about 60kg of pull per ton of stone. That's just a couple of men.

The only difference with your method is that you are storing up energy by lifting the stone and then releasing that stored energy to overcome the friction. You have to create the same total energy in both cases. With dragging the energy is being put in directly and with your method it is being stored up and then released.

Have you tried this with a decent sized block of stone? I bet you'll need an angle much greater than 1 in 15 unless you can provide very effective lubrication. When I experimented with dragging a stone block on a sledge over fixed (dry) wooden sleepers, the coefficient of friction was not much less than 1. That would need a slope approaching 45 degrees.