"What lies beneath the Rubislaw water?"
A crane, a few derricks and a "bicycle" or two!
I read with interest the article concerning "what lies beneath the Rubislaw water?".
I served my apprenticeship from 1962 - 1967 with JM Hendersons which was the largest engineering business in Aberdeen. During this time I was fortunate to service the crane at the bottom of the Quarry. As stated in the article, the bottom is on two levels (ledge) and the crane which is or was at the very bottom was a Hendersons Derrick Crane.
I also had to check the "bicycle", which was an arrangment of sheaves in a frame which straddled the Blondin main cable to enable the hoisting of men, materials and granite blocks to the surface. The Blondin Winch house was built into the quarry face where the operator had an unobstructed view to the bottom.
There was also a set of wooden stairs attached to the quarry face which ran from top to bottom for those brave or fit enough to use.