د.سالم ابوبكر سلطان2026-06-282026-06-28https://dspace.academy.edu.ly/handle/123456789/2389The simplest Roman crane consisted of a single-beam jib, a winch, a rope and a block containing three pulleys. Having thus a mechanical advantage of 3:1, it has been calculated that a single man working with the winch could raise 150 kg (3 pulleys x 50 kg = 150 kg), assuming that 50 kg represents the maximum effort a man can exert over a longer time period. Today crane parts are made of different types of metals, heavy-duty cables, and can lift and move objects many times heavier than the loads of ancient times. In olden times, thousands of slaves had to be arranged whenever a heavy load had to be lifted or dragged Khurmi, (2009). Moving these objects involves some interesting physics. The load is attached to the end of the cable, and then cranked along pulleys to whatever height necessary. The most fun lies in the smallest piece, the pulleyCranes are a complex combination of simple machines. Basically, a lever is used to crank a line of cable through a pulley, or system of pulleys, to lift heavy objects. The first cranes were invented by the Ancient Greeks and were powered by men or animals, such as donkeys. The cranes built by the Ancient Greeks were typically made with wood and rope, and anchored into the ground with large stakes. These cranes were used for the construction of tall buildings. The archaeological record shows that no later than 515 BC, distinctive cuttings for both lifting tongs and Lewis irons began to appear on stone blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the Centre of gravity of the block, or in pairs equidistant from a point over the center of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane. The heyday of crane in ancient times came under the Roman Empire, when construction activity soared and buildings reached enormous dimensions. The Romans adopted the Greek crane and developed it further.mechanical crane drum desingn