1.1. Articulated Jib Tower Crane

There is another type of jib apart from the horizontal boom, luffing boom. You also have this articulated jib tower crane. You can see the picture. See, these articulated jib cranes are able to reposition their hinged jibs to convert the excess hook ridge to added hook height that means so, you can reposition the jib in such a way that.

Articulated jib tower cranes are a special type of crane that can reposition their jibs, allowing them to change their working height. This means that rather than only being able to extend horizontally, the crane can adjust its arm to reach higher without needing additional horizontal space. This flexibility makes articulated jib cranes particularly useful in situations where space is limited.

Imagine having a long ladder that can be moved to stand straight up when you need to reach a high window but can also lay down flat when you want to store it. Similarly, these cranes can 'lay down' their reach or 'stand up' to gain height when necessary, making them versatile tools on construction sites.

So, whenever you do not need excess horizontal reach, you can convert the horizontal reach into vertical height. You can adjust the hinge accordingly. These are also very costlier cranes articulated jibs.

The main advantage of articulated jib cranes is their ability to adjust their reach based on the job requirements. If a construction project requires lifting materials to a height rather than extending a long horizontal arm, the crane can be adjusted to perform this task more efficiently. However, it’s worth noting that such advanced features typically come at a higher cost compared to standard cranes.

Think of this crane like a Swiss Army knife; it has multiple tools and functions. While simple tools are effective for certain tasks, the specialized features of an articulated jib crane justify its higher price, particularly when flexibility in its operation is crucial for the job.

Now, let us see how the erection of the tower crane is done with climbing cage. In modern tower cranes, we have this climbing cage facility which facilitates the self-erection process of the crane.

Modern tower cranes utilize a system called a climbing cage to enable self-erection. This system allows the crane to assemble itself and grow in height as work progresses. The foundation needs to be prepared first, followed by securing sections of the tower to the foundation using a mobile crane for initial setup.

Imagine a tall building being built with self-extending scaffolding that grows taller with each completed floor. Similarly, the climbing cage allows the crane to elevate itself as the construction progresses, reducing reliance on other machinery and speeding up the erection process.

Once this is done, then you can do the self-erection of the tower crane. So, how to do that? First, what you do is, you have to introduce a new section to increase the height of the tower crane with the help of trolling action.

To increase the height of the tower crane, a new section is introduced using a mechanism called 'trolling action.' This involves moving closer the new section to be added, unbolting the turntable, and using hydraulic jacks to lift and make room for the new section. Once in place, the new section gets bolted to the existing structure, effectively increasing the crane’s height.

Consider how you stack building blocks; you remove the top block, add a new block underneath, and then resecure them. Similarly, the crane adds segments one at a time, ensuring stability and continuity in its extended height.

Similarly, if you want to dismantle it, you do the entire thing in the reverse order. So, you can remove the section one by one with the tower crane.

The dismantling of tower cranes follows the reverse of the erection process. This means that once the crane's height is no longer needed, sections can be carefully removed, starting from the top down, to ensure stability throughout the process. If a climbing cage is present, this can also facilitate easier dismantling compared to cranes that do not have this feature.

Taking down a Lego tower is much like dismantling these cranes. You would start from the top and carefully remove bricks one at a time, ensuring the base stays steady, just as the crane needs to maintain balance while sections are being removed.

So, another important thing, you need to know that is the maximum free standing tower crane height permissible is 60 to 120 meters.

The maximum permissible height for a free-standing tower crane is typically between 60 and 120 meters. Beyond this height, additional support structures must be incorporated to prevent instability. This is important to ensure safety and structural integrity.

Think of a tall tree; if it grows too high without sufficient roots or supports, it risks toppling over. Similarly, tower cranes need proper anchoring as they reach greater heights to maintain balance and prevent accidents.

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