Short History of Cranes

Since ancient times, man has used cranes. Used to swing pots and kettles over the fire, the chimney (or fireplace) crane was adjusted by a trammel. Modern cranes follow the same principles.

The Ancient Greeks invented the first cranes for use in construction; they were powered by men, or by draft animals. Bigger cranes were created later, which utilized human "treadwheels". Harbor cranes were introduced during the Middle Ages to load and unload ships, and also to aid in ship construction.

For hundreds of years, men or animals had to exert themselves to supply power, although hoists located in water mills and windmills could be powered by natural forces. In the 18th or 19th century, steam engines provided the first mechanical power for machines. The modern crane is powered by an internal combustion engine, or electric motor and hydraulic system.

Late in the 6th century BC, the Ancient Greeks invented the crane for lifting heavy burdens. The ramp was quickly replaced as the main method of vertical motion when the winch and pulley hoist was introduced. The first time that the compound pulley system is mentioned in literature is in Aristotle's writings.

Crane technology flourished during the Roman Empire, where construction was heavy and buildings reached enormous dimensions. The Romans used the Greek crane and made additional modifications to it. The most basic type of crane used by the Romans was known as the "Trispastos", which was made up of a jib (or boom), constructed of single beams, a winch, a rope, and a block in which 3 pulleys were mounted. In ancient Roman times, the largest crane was "Polyspastos," with a lifting capability of over three tons per person.

A widespread reintroduction of the treadmill crane occurred in the Middle Ages. A large wooden wheel turning around a central shaft, the treadwheel was operated by two people walking side by side. These were normally used in harbors, mines and construction sites. The lofty Gothic cathedrals were constructed with the aid of treadwheel cranes.