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When the boat was moved to water, an unforeseen accident happened. The cargo crane could not hold the load, and because of the disturbed balance, the boat suddenly fell on the water. The boat overturned during the fall, so it drowned. Fortunately, there were no human injuries or victims.
How to build tower cranes and why they do not fall?
Of course, sometimes there are such events, as the boat that dropped from crane or similar troubles. Nevertheless, the cranes cannot be called unreliable. Their silhouettes soar in the sky of all the major cities of the planet; they accurately carry multi-ton cargoes with precision. How they are created and why they do not fall?
Above each city of the world tower giant tower cranes. Their height can reach 70 meters on the ground of tens times more if fastened to the buildings they build. How are these “leviathans” built? How long does it take to create one crane? Why do not they fall?
For almost 60 years, the German crane giant Liebherr produces gigantic cranes. The scale of the enterprise is enormous, as well as the size of the cranes produced.
The height of the crane depends on the tower; it is assembled from four risers connected by diagonal beams. The range of the crane depends on the boom. To balance such a long crossbar, you need to hang a considerable load on the other end.
As the boom moves the mobile unit back and forth, it allows the crane operator to deploy the crane hook in the direction of the specified section on the ground.
These components determine the design and appearance of the crane. None of them would have worked without a huge gear wheel, called a swivel rim; it allows the crane to turn 360 degrees with jeweler precision, transferring loads weighing up to 10 tons.
Assembling the structure
It is easier to assemble this colossal structure than you might think. Often, it takes only several hours to rise a crane. The secret is that the tower cranes collect themselves.
The process begins on the ground. Heavy concrete slabs form a pedestal 1.5 meters thick, it weighs 130 tons, almost as much as a blue whale.
So, the crane is assembled. But why does not it fall? The winds furiously attack the spans of the tower, the rains corrode the steel, it rusts, the earth sags and slips under the enormous weight of the crane, loosens the bolt fastening, loosens the joints and knots, the constant load, the inertia arising from the rocking of colossal loads can split even the sturdiest steel beams. Only welders can save the tower crane from a catastrophe. The amount of work is really gigantic, that’s why even the most qualified welder needs the help of machines, as together they perform the responsible work.
The secret of the strength of the tower sections is the method of assembly. Weld seams mean that neither wind nor rain will penetrate the structure; the result is low aerodynamic resistance & minimal corrosion.
For 60 years, cranes of this design reigned at all construction sites in the world. However, even these gigantic structures have ceased to meet the needs of modern construction. Repair and construction work should now be carried out in the shortest possible time in an extremely limited space, so Liebherr has developed a rapid deployment installation.