What are the different types of cranes?
Cranes are machines that use levers and/or pulleys to lift significant weights. A crane one passes on the road may look like a fairly modern invention, but these machines have actually been used for at least the past 2000 years, if not longer. The Romans used cranes to build huge monuments. Medieval churches were constructed with them. Also, the Egyptians may have used them to create pyramids. The modern version can be either simple or complex, and cranes vary based on their application. A relatively simple crane is the mobile crane. A telescopic boom (arm) or steel truss mounts its movable platform. Either pulleys or levers raise the boom. Generally a hook suspends from the boom. The platform of a mobile crane can either have traditional wheels, wheels designed for railroad tracks, or a caterpillar track, which is useful for navigating unpaved and uneven surfaces. Mobiles can be used for demolition or earthmoving by replacing the hook with an appropriate tool, such as a wrecking ball
