How Does a Crane Work?

by Larry Peck

What Is a Crane?

A crane is an advanced machine that utilizes several simple tools to raise and lower items. It can also move horizontally. A crane comprises of ropes, cables, winder, or chains. Winder and sheaves are a type of puller.

The Anatomy of a Crane

Cranes are crucial for any large construction site. Keep in mind there are different types of cranes. However, there are designed to do the same job- to move and lift heavy loads. Cranes are mobile machines because they must travel from one area to another in the construction site, as well as to different parts of the world.

Cranes on the water

If you have seen a crane in action, you may have asked yourself how the arm can support and lift heavyweight, and it is not toppling over. Well, there are several physics and engineering feats that make lifting possible.

The majority of cranes come with several cables and pulleys to lower and lift pieces of material and equipment. Think about turbines, generators, slabs of concrete and many different types of materials that are heavy.

Here is the basic anatomy of a crane:

  • The boom

This is the end of the crane. It is long steel that features a hook or another specialized item on end.

  • The hook and ball

The size and shape of the hook vary based on several things like what industry it is used for or the amount of weight the crane can carry. For instance, big steel claws used in scrap fields to haul big steel debris. For other applications, a hook is ideal for moving large shipping containers to and from a port.

Hook hanging from a crane
  • The Jib

The jib is either attached either at the bottom or on the top. It is the part that lifts the load and extends to the boom to enhance mobility. It can be likened to a wrist while the boom is like an arm, and the hook is the crane’s fingers.

  • Counterweight

The counterweight is designed to ensure that the crane isn’t toppling over because of the weight differential. It can either be located near the cab of the crane or at the base of the crane. It helps to counterbalance weight when lifting a load with the boom to make sure workers and the construction site are safe.

  • Outriggers

Major movements in balance happen when operating a crane because of the weight of the load. They are used to help counterweights to stabilize the crane by utilizing hydraulics to lift to carry the entire unit at once.

  • Steel Cables

The steel cables are used together with an arm. An ordinary capable can carry up to 10,000 pounds of weight or even more. Different types of cables are used for different kinds of jobs with others being capable of carrying more weight than others.

Tower crane

How A Hydraulic Crane Works

A hydraulic system powers a crane. The system activates when a piston presses the oil down, which transfers the initial force to a piston and then upwards. When the piston is pressed down, another one pushes up. A hydraulic pump exerts pressure that moves the pistons up and down, while the pressure in the system is made by two types of hydraulic pumps: gear pump and variable displacement pump.

The majority of cranes use gear pumps that feature a pair of gears that push the hydraulic oil. When the pressure is supposed to increase, the operator presses the accelerator to make the pump work faster. For a gear pump, the pressure can only hire if the engine runs at full power. You can reduce or extend. When the pistons are attached to levers, you can use them to lift heavy weights, just the way hydraulic cranes do.

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