Cranes also make use of the pulley, another simple machine. In this way, the crane’s beam acts as a simple lever. This allows it to lift heavy objects with a relatively small force. In balance-style cranes, the crane’s beam is balanced at a point, called the fulcrum. Finally, the operator cab contains the electronic controls used to operate the crane.Ĭranes combine simple machines to lift extremely heavy objects. It contains the crane’s motors, along with large concrete counterweights that help balance the load. The machinery arm is shorter than the jib. The jib uses a trolley to help carry the load.
You’ll also find the working arm, machinery arm, and operator cab. For example, the mast of a tower crane is usually bolted to a large concrete pad that can weigh as much as 400,000 pounds!Īt the top of the mast, you’ll find a gear and motor that allow the crane to rotate. To do so, it must be supported by a large, heavy base. It looks kind of like the mast on a ship! But instead of a flag or sail, this mast raises building materials. The tall part of the crane that sticks up in the air is called the mast. Instead, they load these objects onto a crane and carefully put them in place. Concrete and steel beams are much too heavy for construction workers to carry up stairs. Without them, it would be very difficult to lift heavy construction materials and equipment. Tower cranes stay in one place and lift large loads to great heights. Visit a site where they’re building a tall tower, and you’d be most likely to find a tower crane. But how do they work?Ĭranes can be found at construction sites around the world. In many large cities, cranes are as much a part of the skyline as tall buildings themselves. These tall machines are used to lift all those heavy building parts high into the air. If you’ve ever seen a building being built, you know it’s done with a crane. How do they get all those building materials so far up? Have you ever WONDERed how people build such tall structures? Think about how high up they have to move heavy beams and huge panes of glass. Was it the Empire State Building? The Washington Monument? Maybe it was the Shanghai Tower. Think of the tallest building you’ve ever seen.