The tower crane is very common and very important at construction sites when the building being erected needs to tower hundreds of meters above the ground. It can not be missed when present thanks to its enormous size. Tower crane is used at the construction site to do heavy lifting especially when the object or material needs to be lifted high into the air to the place where it is needed. The main object/material cranes are used to lift is heavy equipment, Steel, acetylene torches which are very big, concrete and sometimes generators.
Tower cranes are made in such ways that one just can’t help wondering something so thin manage to carry objects weighing tons of kilogram without tipping over. This article was created to answer the questions you are curious about and give you details on how the crane lift heavy weights while it also seemingly increase in height. There are a lot of insights in this article that will give you a colorful understanding of how tower cranes work
Description of a Tower crane
Before you can understand the workings of a tower crane you need to know just how essential every part of the machinery is. The plain truth is that erecting, they take a lot of preparation in other to make them standard. There are different parts that make up a tower crane and every part has a role to play when the machine is at work. The most important part is the base. This holds it firmly and prevents it from falling.
- The Crane’s Concrete Base
The base is the only thing that stops a Tower crane from toppling over when it’s being used at a construction site. It has to be strong enough to bear the weight of any operation to be carried out with the crane. The base has to be built into a very secure foundation which is usually made of concrete slabs.
The crane is not completely built at the construction site. The base is the first thing that is erected before the other part of the crane joins it at the site. A vertical piece of the crane has to be fixed to the concrete foundation with thick bolts. The amount of concrete at the base of the tower crane totally depends on the type of work the tower crane will do. All Tower crane bases usually weight above 400,000 lbs.
- Other parts of the Tower crane
Building the crane is complicated. Once the base has been erected, the next thing is to add the rest of the parts that make up a Tower crane.
Transportation is a very important part of this process. There are lots of small processes that have to be in place and taken into consideration. The small processes are:
- Budget: The amount of money it will cost to transport the rest of the parts of the Tower crane to complete its construction. The expenses incurred to transport these parts because of the heavy hauling attached means it has to be duly accounted for
- Routes: The parts are heavy and some of them are big. They have to be transported at specific times while using routes that can accommodate the kind of objects to be transported.
- Transportation Schedule: Everything has to be right when a tower crane is being constructed. Not all the parts of the Tower crane will be transported at once. They have to be transported in batches in the order that they would be assembled. Not just this, the time every part of the Tower crane will be transported has to be coordinated.
- Erecting the Tower Crane
As earlier stated, a tower crane is not constructed or erected at the construction site. it is brought in in pieces and built until it becomes the towering machinery capable of lifting anything you want it to.
After transporting the parts of the Tower crane to the construction site, the first part of the crane to be developed is the vertical mast. This is done by adding more masts sections on the already constructed concrete base foundation at the construction site. The mast sections together with the other crane parts are heavy and have to lifted by other equipment and machines. The most popular ones are Mobile Cranes, Crawler cranes, etc.
Once the mast sections being added reach the desired height needed for the building about to be constructed, the operator’s cab and the turntable will be added to the top of the mast.
The Operator’s cab is where all the magic happens. The cab and the turntable are the heaviest part of the Tower crane. They have to be lifted by machines. The cab contains controls that allow anyone in the cab to lift anything he or she wants with the crane.
After the operator’s cab comes another important part of the crane. This is referred to as the tower top and it is placed at the top of the crane. The tower top is not the last piece to be attached to the crane. The working arm also called jib has to be connected to the turntable in a horizontal manner. The attached working arm has a hoist, a trolley mechanism, and a hook. Since the jib is essentially used for lifting, it is only right that it has all the attached parts.
The jib is not the only part tasked with the lifting work. there is also a counter jib just behind the operator’s cab that also has a few attachments. The attachments make it possible to use the tower crane without any fear of overbalancing.
The last detail that makes a tower crane fully function is the attachment of ropes. The rope is what attaches the hook to the trolley mechanism that is attached to the jib of the Tower crane.
Operating the Tower Crane
Almost all tower cranes have their control center at the top of the crane in a cabin. Only the most skilled team of individuals are allowed to operate the crane because of the efficiency and accuracy needed.
The team members are specially handpicked for the job. This means that they are the only ones with the skills to handle the job. Each member of the team has more than one duty to perform during the operation. There is someone who acts as team leader and appoints tasks to the rest of the team based on their talents and skills; there is the signalman who handles the signaling and also acts as the operator’s cornerman when the crane is being operated; there is the operator who is tasked with the sole job of controlling the tower crane based on the instructions of the ‘signalman’; there is also the crane coordinator who has to schedule the sequence and time every object to be lifted is actually lifted.
The signalman has one of the hardest jobs among all of them. He or she has to quickly analyze the building they are trying to construct. He or she then has to send instructions to the Operator in the cabin at the top of the crane on what to do. When the team dedicated to operating the tower crane complete the task set for them and there are no more heavy lifting to be made, the tower crane has to dismantle.
Dismantling the Tower crane
The tower crane is always dismantled when the construction work is complete. It is advisable to dismantle the crane as soon as the team working with it is done with it. The amazing thing about the procedure here is that it is the exact reverse of the way it was built.
The tower apex is first removed followed by the Operator’s cable and the mast sections. This process is however easier said than done. This is because when the Tower crane was being set up before the construction began, there were lots of workspace for the erection of the crane. Once the construction of the building is complete, there is a smaller space available for use. This usually makes dismantling the erected tower crane a herculean task. It requires patience and skills to safely dismantle it without any damages to surrounding buildings. An alternative is to dismantle the tower crane as soon as the team in charge of operating it completes the task. This is not that good because if a mistake occurs and the crane has been dismantled, it would have to be re-assembled!
Once the Tower crane is dismantled, the parts are now returned in the same order they were brought in when the tower was just about to be erected.