The skyline of any city will likely include at least a few tower cranes, which are among the largest pieces of equipment used in building projects.
Construction companies use tower cranes to lift heavy materials such as steel and concrete.
Large devices like acetylene torches, motors, and generators are also transported using tower cranes.
Since tower cranes are slender compared with high-rise buildings, their lifting capacity can be easily underestimated based on appearance.
How are cranes built?
- How can the tower crane stand without tipping over?
- How is it capable of lifting so much weight?
- Does the crane become taller along with the building?
In this post, the basic principles of tower cranes and their functionality will be discussed.
One of the first questions someone looking at a tower crane may ask is how these structures stay upright. Several elements contribute to the tower crane’s stability.
How Are cranes built on skyscrapers?
Tower cranes are delivered to construction projects in parts, which are then assembled on-site.
Qualified installers assemble the jib and the machinery section, these horizontal elements are then positioned on the mast, which is only 40 feet tall initially.
Once this assembly is completed, the counterweights are placed by a mobile crane. The mast rises from the concrete pad, and it remains upright thanks to its triangulated structure.
To increase the crane height, the crew adds sections to the mast with a climbing frame:
A weight is hung on the jib to balance the counterweight.
The slewing unit is detached from the top of the mast and hydraulic rams in the top climber push the slewing unit up 20 feet.
The crane operator uses the crane to lift another 20 ft mast section into the gap and then it is bolted in place.
These steps are repeated continuously until the desired height is achieved.
Once it is time to remove the tower crane from the construction site, the crane disassembles its own mast and smaller cranes are used to disassemble the rest.
Why Don’t Tower Cranes Fall Over?
This is mostly down to the concrete base, which is massive and needs to be poured weeks before the crane arrives. The triangulated cross-member structure of the mast gives it more stability and prevents bending. Plus, it’s anchored and bolted to the ground.