They are the architect of every skyscraper, apartment block, shopping centre, and almost every other building. They are synonymous with developing skylines as they soar hundreds of meters into the sky. But have you ever wondered how such a slender piece of machinery stays upright? Even when manoeuvring large chunks of metal and piles of bricks? This article explains the science behind a tower crane and how they allow us to build bigger.
We all know that tower cranes are used on construction sites to help sculpt new buildings, but what exactly do they do? Cranes combine sheer height with lifting ability to quickly transfer heavy materials up multiple stories. Without them, this task becomes very arduous and painstakingly slow, so cranes ultimately speed up the construction process while simultaneously making a whole lot easier. So that’s what they do in a nutshell, but how do you build the thing that builds?
How A Tower Crane Is Built
The most obvious concern with a 100-foot crane is the balance. Being such a lanky piece of machinery, there needs to be a way for a crane to stay upright while it handles tonnes of material. So how is this achieved? Well, the process isn’t dissimilar to building a skyscraper for the most part.
Before a tower crane is assembled, foundations are dug for the crane, with the bottom part attached to steel rods that lie in the foundations. Once the concrete has set, the crane can start being put together section by section. A mobile crane holds the sections of the tower crane into place as it secured with a hydraulic wrench. The heaviest part of the crane is the turntable, the area in which the cabin rests on, and once that is fixed into place, the articulated arm, known as the jib, can be wrenched on.
For the tower crane to function, ropes are added to the jib alongside a trolley system, and is wired up to the control pad in the cabin. This briefly explains the structural aspect of the crane, but the topic of balance is still very poignant at this point.
A counterweight is added to the opposite end of the articulated jib to counteract the weight that the crane will be lifting. Many cranes have a counterweight which s adjustable depending on how much weight is being lifted, but for the most part, the weight is secured just shy of the end of the jib. The crane can also be fixed to the side of buildings via braces to keep it upright, but this is only if the building that is being worked on is already standing at a considerable height.
The technology of the tower cranes control system will stop the crane from lifting anything that will unbalance it, but the final stages of making a crane operational are testing stages. This is where the tower crane lifts varying weights, building up to its maximum capacity. If all these tests are passed then the crane can join in with the construction process.
How Much Does A Tower Crane Cost?
Prices vary from company to company, so the only real gauge of price is between the various types of crane.
A flat-top crane is usually the cheapest, as the jib acts in one direction only, whereas a crane with an articulating jib, ones which are quicker and have a greater range of motion, can be more expensive. A luffing jib crane sees the jib rotate higher than any other tower cranes, and these lean towards the far end of the price range.
If you are unsure of the type of tower crane needed for your construction project, you can contact NMT Crane Hire and talk to one of our advisors to discuss your needs and requirements.