Construction crane

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

The first crane appeared in 1830 in Great Britain. It was a steam version. A more advanced model, already hydraulic, was designed 17 years later. But if earlier, when the first cranes appeared, the work was carried out by and large by hand or partial mechanization, today any construction site, from small to large, has a construction crane at its disposal.

A bit of general information

It must be understood that there is no such device as a construction crane. There are cranes. This term was introduced by Gosgortekhnadzor. The definition was roughly as follows: a crane is a machine that has a lifting device (hook, grab, etc.), which is used to lift and move heavy loads.

Today, this technique is actively used in construction. In principle, from an economic point of view, this is enoughprofitable. A modern crane can lift a load of over 1000 tons, but typical 50-ton trucks are suitable for construction.

Work cycle

It should be understood that in order to lift and move the load, the operator needs to perform simple manipulations (cycles). At the first stage, the seizure of the cargo is carried out. If it is a concrete slab, then it is tied, and a hook is used to lift it. If it is bulk material, the work is carried out with a grab. The second stage is the workflow. It consists in direct movement, as well as unloading of the material being moved. In fact, this is the most crucial stage, so the work must be carried out smoothly and without jerks. The final stage is idling. It involves returning the load handling device to its original position. By the way, the working stroke consists of three stages: acceleration, steady motion and braking. The first and third stages are the most important, since it is on them that dynamic loads appear and, therefore, the risk of damaging the transported cargo.

Construction crane and its structure

By and large, the unit consists of several important components. Let's take a look at each one:

• Metal construction is the basis of a construction crane. All that can be attributed here is spans, supports, arrows, etc. It is worth noting that they are of box-shaped and lattice type. In construction, box-shaped metal structures are more often used.
• Lift mechanism - consists of a flexible lifting body. It can be a rope or a chain. It is also worth mentioning herelifting device (loop, grab, hook, etc.). In construction lifting equipment, hook cranes are most often used.
• Load lifting device - not automatic (hook or loop), requires little manual work, and automatic (electromagnet or pneumatic suction).

As you can see, a construction crane is a rather complex device that needs constant supervision and replacement of ropes, hooks and other parts and assemblies.

Classified by design and mobility

It's worth noting right away that there is no single classification that would reflect the full essence. The fact is that modern cranes can combine several functions at once. So, there are the following construction cranes, depending on the design:

• Boom - in this case, the load gripping body is mounted on the boom. It is these cranes that are most often used in construction, as their maneuverability and mobility allows you to perform all work quickly enough.
• Bridge - a metal structure is a bridge to which a load-handling body is suspended.
• Cable type taps.

As for the possibility of movement, it makes sense to say only about two main types: stationary and self-elevating. The latter type is just used for the construction of buildings. Its peculiarity is that it is installed on the object under construction. As the building grows, the crane is lifted using special mechanisms. Although in recent years allmobile jib truck cranes are more often used, which are in the lead in many respects in terms of technical characteristics. Such a construction crane is adjusted if necessary and easily moved to another object. Let's move on now.

Construction tower cranes

Tower cranes are the most rational in civil and industrial construction. This is due to the fact that they allow installation, dismantling and transportation by vehicles. This allows you to reduce production costs by speeding up work. But sometimes such a crane cannot be used due to insufficient space. In this case, a fast-erecting tower crane is used. This type of construction hoist is good because it does not need a lot of space to install it. True, such a lifting device cannot be used with a building height above 30 meters. It is interesting that in one shift the crane can be dismantled and assembled at another construction site with minimal production costs. Today it is one of the most cost-effective solutions after truck cranes.

Pneumatic wheel and crawler crane

The variant, working on a pneumatic wheeled chassis, is good because it has increased cross-country ability. In principle, such a construction crane, the photo of which you can see, is used in close proximity to the object. This was achieved by installing several controlled axles. In addition, the operator's cab is quitecomfortable. There is a computer that almost completely eliminates the human factor, air conditioning, etc. systems.

There is also a crawler crane. It is mounted on a tracked chassis. Despite the high cross-country ability, such equipment is able to work effectively only on pre-prepared sites. Transportation is carried out using a special trailer, which increases operating costs. That is why such construction equipment is not used everywhere. Taps of this type are used only where any other is not suitable.

Conclusion

So we figured out what a construction crane is. You can find photos of several popular models in this article. I would like to note that today such lifting equipment is used everywhere. It reduces the risk of injury in production and reduces the amount of manual work. There are a large number of cranes, this applies to both their types and load capacity. Some are designed for fast work and mobile movement to another object, while others, on the contrary, lift slowly, but rather heavy loads, and stand on objects for weeks or even months.