The silhouette of the spires above the rooftops of major cities is now a common sight. What's a little more exciting, as we explored in our last post, is how such a tall structure is built. Today's article is all about how a tower crane works and operates.
The tower dwellers carry out hundreds of lifts per project and use a wide variety of building materials (concrete elements, steel structures, pipes and other heavy materials) are moved into position several storeys high for installation by workers on the site.
However wide the range of materials that can be craned, the lifting itself consists of essentially the same process steps.
The crane process
To secure the load, the crane operator in the cab guides the machine and the trolley to the correct position and then lowers the on a wire rope hanging hook.
Workers at ground level according to the rules, stable are recorded on the materials to be lifted, and then signal the crane operator if he can lift.
The crane operator then starts to lift the load by coordinating the lifting of the boom hook, the movement of the trolley along the entire length of the boom and the horizontal movement of the boom.
The two joysticks (one for horizontal and one for vertical movements) and the two joysticks for the control of the tower cranes hydraulic systems and electronic sensors, and some practice, very fine and precise manoeuvres can be performed, even with loads of several tonnes. And in the case of a single tower crane, over a very large area.
The largest free-standing tower crane, the Kroll K-10000 has a range the size of six football pitches.
What does the crane operator do?
All these manoeuvres are carried out by crane operators. This job is not recommended for people who are afraid of heights, as there are a number of ladders to climb up at the beginning of the shift and down at the end.
At the beginning of the shift, the tower crane operator is also required to carry out a full inquiry to ensure that the crane is fully suitable for safe operation.
Although the view from the high cab is very good, the crane operators have to receive instructions by radio in addition to hand signals from the ground level workers, especially the person in charge of the crane, who is designated to give signals.
Communication is of course two-way to ensure that lifting and handling is as safe as possible in all cases.
Proper communication can significantly reduce the chance of accidents occurring.
For safe lifting, modern cranes, including tower cranes, advanced electronic systems are equipped with a set of monitor wind direction and speed, and the position of the bell and the gerbil determine for the crane operator the maximum amount of loads that can be lifted.
The handling of tower cores is therefore a dangerous operation, but the safety rules the cranes are regularly maintained by, and with focus and good communication, the danger of lifting can be significantly reduced.
