I started drawing scale models and, within a few months, I got the conviction that the subterranean southern passage was intended as a shaft similar to those in the upper chambers, although bigger. The lay out of the chambers and shafts made me think of a geometrical puzzle designed to reveal secret structures. I then developped a theory according to which there would be a secret entrance in the southern part of the pyramid, below ground level. Of course, it would mean that once the pyramid was completed there was no access to the burial chamber of the pharaoh.
Measurements are in Egyptian royal cubits.