In this blog post, we’ll explore the structure of the tower crane—often called the “flower of the construction site”—and examine the principles behind its installation and dismantling processes.
The Tower Crane: The “Flower of the Construction Site”
The tower crane is one of the key pieces of equipment on a construction site and is the first thing that catches your eye at high-rise construction sites. Walking down the street, it’s easy to spot a tower crane standing tall at a construction site. Seeing heavy materials—too heavy for humans to lift—suspended from the crane as they move through the air, or witnessing multiple tower cranes working simultaneously across a vast construction site, can be an awe-inspiring sight. As the key piece of equipment for moving and lifting such heavy machinery and materials, the tower crane is often called the “flower of the construction site.” This “flower” overlooks the construction site from a height greater than the building under construction, guiding the entire construction process. However, how tower cranes are installed at such great heights—and how they are dismantled—is not widely known. Let’s take a look at how this massive “flower” blooms and how it eventually disappears.
What is the structure of a tower crane?
To understand how a tower crane is installed, we must first understand its components. A tower crane can be broadly divided into four parts. The first is the mast—the steel column at the base that we commonly see. During the construction of high-rise buildings, it is common to see this mast rising to heights of several dozen meters or more. Above the mast is the upper structure, which consists of the jib and the counter jib. The jib is the main working arm of the tower crane; it uses pulleys and wires attached to its tip to lift and move heavy materials. The counter jib, located on the opposite side, serves to maintain the crane’s balance; it is fitted with a counterweight of a specific mass to balance the jib and its load. Finally, a telescoping cage is installed between the mast and the upper structure. This device plays a key role in increasing the height of the tower crane.
How does a tower crane get taller?
The initial installation process for a tower crane is relatively simple. First, the ground is thoroughly compacted, then the foundation mast is erected, and the telescoping cage and upper crane are installed on top of it. However, the height of the mast installed initially is not very great. As construction progresses, masts are added one by one to match the height of the building, gradually increasing the tower crane’s height. An interesting fact is that the mast, which we tend to think of as a single long column, is actually a structure composed of several short masts connected together. The telescoping cage is precisely what makes this height extension possible.
The telescoping cage operates using hydraulic cylinders. To raise the crane’s height, the hydraulic system is activated to create a specific gap between the upper crane and the topmost mast. A new mast—which has been lifted into position in advance—is then inserted into that gap and securely fastened with bolts and nuts, raising the tower crane’s height by one stage. By repeating this process, the tower crane grows in tandem with the building as it rises.
How is a tower crane dismantled?
So, how is a tower crane dismantled once construction is complete? As you might have guessed, the dismantling process follows the reverse order of the installation process. First, the upper crane is lifted using the hydraulic system of the telescoping cage. Next, the mast connected to the very top is detached and removed; when the hydraulic system is returned to its original position, the tower crane’s height is reduced by one stage. By repeating this process and removing the masts one by one, the crane’s height gradually decreases. Eventually, it is lowered to a height where workers can manually disassemble it, and once all components are dismantled in sequence, the tower crane’s duty at the construction site is complete.
Through this process, we can see that a tower crane is not merely an imposing or mysterious presence. Although various precision equipment and machinery are used on construction sites in addition to tower cranes, once you understand their principles, the construction site—which once felt unfamiliar—becomes much more approachable. If you gain even a basic understanding of the structure and operating principles of the massive tower cranes you see beyond the fence, the psychological barrier between you and the construction site will be significantly lower than before.
