In the historical record, lifting devices for water first appeared in Ramses’ Egypt. While scholars have concluded that some kind of crane must have been used to build the pyramids, it was in ancient Greece that signs of crane technology were first seen.
The first evidence of a crane came in buildings constructed in 6th century BC. The blocks used in construction had holes that indicated the presence of a lifting device. Because the holes were above the center of gravity of the block or in pairs an equal distance from a point over the center of gravity, archaeologists believe that a crane was used to lift them into place. They also believe that the crane used a ramp for vertical movement – the same method the ancient Egyptians very likely used.
The Greeks later developed a simple but effective winch and pulley system that replaced the ramp and enabled them to lift heavier blocks. It is believed that cranes like this were used to erect buildings like the Parthenon.
From ancient Greece, the crane’s history takes us to ancient Rome. The Romans took the Greek crane and improved it, giving themselves the ability to build huge structures. Early Roman cranes had a three-pulley system that, it is believed, enabled them to lift up to 150 kg. From there, the Romans extended the size and lifting capacity of their cranes.
The early three-pulley crane gave way to a five-pulley crane. This innovation was soon replaced by a treadwheel, which took the place of the winch. With the treadwheel’s larger diameter, load weights increased to 6,000 kg. As a Wikipedia entry notes, this meant that the lifting capacity of an ancient Roman crane – where 2 men could lift 6,000 kg – was 60 times higher than the ramp system used in Egypt, which required about 50 people to move a 2,500 kg stone block.
The Romans developed crane technology even more, through use of a lifting tower with four masts, surrounded by capstans which were turned by people or animals to tighten the ropes and lift the load. This crane allowed them to lift blocks of several tons to heights as high as 34 metres.
Shifting to the Middle Ages, crane technology finds its way to the harbour. Cities in Belgium and Germany used harbour cranes as early as the mid-1200s. Cranes from this era used the treadwheel design favoured in ancient Rome.
The technology changed little until the 1800s when crane manufacturers began using cast iron and wire rope. These innovations made the crane stronger, more durable, and more capable of lifting heavy loads.
After a few more innovations, like the addition of arch-shaped jibs, the first mobile crane was developed. Mounted on train cars, these cranes moved along short rail lines constructed specifically for each project in which they were employed. By the 1920s cranes were mounted on crawler tracks to become the crawler cranes we are familiar with today.
The next major innovation came in World War II with the advent of hydraulic technology, which was incorporated into cranes by a Swedish ski manufacturer. In the 1940s, Eric Sundin discovered a way to convert the power in a truck’s engine into the power needed to generate a lifting motion. In 1944 he founded Hydrauliska Industri AB Co. (now known as HIAB). By 1947, the company had produced the world’s first hydraulic truck mounted crane.
Which brings us to today, when cranes like those built by HIAB can lift 100 tonne-meters and reach as far as 28 m.
A very impressive history, wouldn’t you say?