Reproduction of a crane - Selinunte

A crane for lifting heavy loads was invented at the end of the 6th century BC. developed by the ancient Greeks.

Characteristic holes for lifting eyes have been found on stone blocks of Greek temples. These holes indicate the use of a lifting device because they are located directly above the center of gravity of the block, or in pairs equidistant from a point above the center of gravity.

The arrival of the winch and pulley hoist in the so-called trispastos ("triple pulled - to the 3 pulleys") soon led to the replacement of pushing the stone blocks on sloping ramps that had until then been the main means of raising the blocks to get. This crane was also widely used by the Romans. After the disappearance of Roman civilization, knowledge of the crane was largely lost.

The builders had the option to secure the load in between . This was an important feature of the design as it allowed them to lift, move and deposit the load at the desired location in a controlled manner.

The lifting capacity improves according to the number of pulleys. 3 pulleys provide a lifting capacity times 3; 5 pulleys times 5. Calculating that 1 man can lift 50 kg for a long time, then the lifting capacity with a crane occupancy of 2 men is 2 x 50 x number of pulleys or 300 kg or 500 kg for 3 and 5 pulleys respectively.

The winch was later replaced by a treadmill (a wheel on which one could walk).

Willem Vandenameele