The crane for medium load

Its “mast” consisted of two giant pieces of wood in the form of Λ. Its articulation was ensured by two dents in the ground. Its stabilisation in various inclinations was achieved by two balancing ropes that were tautened with block and tackles and levers of traction.

The load was lifted or lowered with the help of the “trispasto” pulley and a horizontal axle, the “reel”, (where the rope for the lifting of the load was wrapped) and was turned with the help of mobile levers (around special bearings, “tortoise-like cases” which were fitted on the beams of the mast). For the reduction of friction, the axle had two small metal shafts at both sides rotated to specific receptors within the “tortoises”.

SOURCES: Vitrouvius, On architecture, X.