4.4. Rigging Safety

There is another type of jib apart from the horizontal boom, luffing boom. You also have this articulated jib tower crane.

The section starts by introducing two types of jib cranes: the horizontal boom and the luffing boom, highlighting the articulated jib tower crane. Each type of crane has different functionalities suited for various tasks in construction.

Think of these cranes as different types of vehicles. Just like trucks and sports cars serve different purposes on the road, these cranes have specific uses depending on the construction needs.

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 cranes have the unique ability to adjust their jibs. This means that when construction workers don’t need the jib to reach out horizontally, they can change its position to gain vertical height. This flexibility is vital for achieving different heights without demanding too much horizontal extension.

Imagine a painter using an adjustable ladder. By repositioning the ladder, the painter can easily reach the top of a hall without having to stretch out too far or climb higher than necessary. Similarly, articulated jibs help maximize height while minimizing reach.

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.

Tower cranes can be erected using a climbing cage, a modern facility that allows for self-erection. The process starts with preparing a strong foundation, followed by adding sections of the tower. Workers initially need a mobile crane for assistance, but once it is set up, the climbing cage allows for independent height adjustments.

Consider building a tall bookshelf. Initially, you might require a friend to help you lift the first few shelves, but once the structure is secured, you can easily add more shelves by yourself. The climbing cage functions in a similar way for tower cranes.

First, you have to prepare the foundation for the tower crane that is very important. You have to prepare a heavy foundation for the tower crane according to the requirement.

The erection process begins with a solid foundation tailored to the crane's needs. Heavy reinforcement is essential to support the structure adequately. After the foundation, the tower sections are installed before erecting components like the turntable and climbing cage. This careful stacking is crucial for stability and functionality.

Think of setting up a tall tree house. Before building the tree house, you need a strong base, such as strong branches or a sturdy platform, to ensure it can support the weight and height safely. Similarly, the crane needs a solid foundation to operate effectively.

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.

In the self-erection process, an additional section is introduced to elevate the crane’s height. This is done using a trolley system that helps bring the new section closer. The turntable base is then unbolted and lifted, creating space for the new section, which is subsequently bolted into place. This method allows the crane to grow taller as needed without much external help.

Imagine adding another layer to a cake. You first create space on the cake's top by gently lifting the upper layer, and then you place the new layer on top before frosting it all together. This is akin to how sections are added to the crane.

If there is no climbing cage, we need the support of another mobile crane for the entire process.

Dismantling a tower crane can be done efficiently with a climbing cage, allowing workers to remove sections without additional crane support. If a climbing cage is absent, however, they must rely on a mobile crane throughout the entire dismantling process, which involves carefully removing components like the jib and counterweights in reverse order.

Consider taking apart a toy tower. If you have help from a friend, you can easily lift and remove the top pieces. Without help, you may need to dismantle from the bottom and work your way up, making the task longer and more complex.

The maximum free standing tower crane height permissible is 60 to 120 meter.

There are specific height limits for tower cranes, usually spanning from 60 to 120 meters. Beyond this, they require additional structural support to maintain stability and prevent tipping. If a project exceeds these height limits, it may necessitate a special type of crane designed to grow alongside the structure.

This can be compared to stacking building blocks. You can only stack them safely so high before they topple over. To create a taller building, you would need a wider base or extra clamps to hold the blocks together securely.

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