When it comes to iconic symbols of urban development and construction, the towering presence of a crane against the city skyline is hard to miss.
These impressive structures dominate construction sites, an indispensable part of any major construction project.
In this blog, we will look into the world of tower cranes, looking at the different types of tower cranes, exploring their purpose, usage, power sources, anchoring methods, and the process of dismantling them.
What is a Tower Crane?
A tower crane is a large and robust piece of construction equipment used to lift and move heavy materials and equipment on construction sites.
There are a few different versions of the tower crane, but it usually consists of a tall tower-like structure that is firmly anchored to the ground and a horizontal boom (also known as a jib) that extends out from the top of the tower. The boom is capable of lifting heavy loads and can be raised or lowered as required.
Tower cranes are known for their impressive lifting capacities, which can range from several tonnes to over a hundred tonnes. They are essential in the construction industry for tasks such as erecting tall buildings, lifting steel beams, placing concrete panels, and transporting construction materials to various heights.
Tower cranes are usually operated by skilled crane operators who manoeuvre the crane’s controls from a cabin located at the top of the tower, providing them with a clear view of the construction site.
Let’s take a look at the different types of tower cranes.
1. Mobile Tower Crane
Mobile tower cranes are moveable cranes attached to heavy-duty vehicles that can be driven and easily set up on a construction site.
As it is easy to set up, take down and move between projects, the mobile tower crane is commonly used for city projects and those within confined spaces.
2. Self-Erecting Tower Crane
A self-erecting tower crane is a fixed crane that can be placed almost anywhere on site.
It requires little space for operation and installation and can be used in various construction sites of all scales.
3. Saddle Jib Tower Crane
A saddle jib tower crane is a type of tower crane that has a fixed horizontal jib that is supported by a saddle which is attached to the tower and can rotate around the tower.
Saddle jib cranes offer many benefits such as being generally cheaper to hire than a luffing crane, with quicker operation, lower power and being easier to erect and dismantle. They can be placed onto a ballast base or fixing angles and climbed to great heights if required.
4. Luffing Tower Crane
A luffing tower crane is a type of tower crane with a jib that changes the angle to increase and decrease the working radius.
Luffing cranes are commonly used in work areas where the crane is unable to oversail neighbouring properties, or there are buildings and structures that impede movement.
The jib of a luffing crane is able to raise or lower itself, which allows it to reduce the slewing radius. This makes it a good choice for work sites where two or more cranes are working at the same time.
How are Tower Cranes assembled?
The assembly process will change depending on the type of tower crane that is being used. But building a tower crane is always a detailed process that requires careful planning, engineering expertise, and a well-coordinated team effort.
Safety is of utmost importance during the assembly process. Tower cranes undergo rigorous inspections and are subjected to strict safety regulations to ensure their stability, structural integrity, and functionality.
How are Tower Cranes anchored?
Have you ever wondered why tower cranes don’t fall over? The stability of a tower crane is essential for safe and efficient operation. Anchoring methods are used to secure the crane and distribute its immense weight.
Where possible, the most common anchoring method for tower cranes involves fixing them to the ground using concrete foundations. These foundations are created by pouring a large amount of concrete into excavated holes or using precast concrete blocks. The weight of the crane is then distributed evenly across these foundations, ensuring stability even during strong winds or heavy loads.
In certain cases, where ground conditions are less stable or space is limited, tower cranes may be anchored using ballast. Counterweights, typically made of concrete or steel, are placed on the crane’s base to provide stability. The weight of the ballast counterbalances the load and prevents the crane from toppling over.
How are Tower Cranes taken down?
Once a construction project nears completion, the time comes to dismantle the tower crane. Tower cranes are typically dismantled in sections, starting from the top. If needed, a smaller mobile crane is used to reach the uppermost sections and detach them from the tower.
Tower Cranes: A sight to behold
Tower cranes are an impressive sight to behold, showcasing the UK’s commitment to construction excellence and progress.
With their ability to lift heavy loads, their environmentally friendly power sources, and robust anchoring methods, these engineering marvels enable the creation of remarkable structures that shape the nation’s skyline. As construction techniques evolve and urban landscapes transform, tower cranes will continue to play a vital role in shaping the future of the UK.
