Unlike a conventional telescopic boom, our Triple-Boom System consists of not one but three telescopic tubes. These tubes give the overall system a permanently high level of flexural and torsional stiffness. It is pure physics: the further away the materials of a load-bearing structure are from the center of that structure’s cross section, the more stable the overall system will be.
It is precisely this principle that we employed in our new Triple-Boom System. The mass of the total amount of available steel is no longer distributed in just one main boom, but instead between another two telescopic tubes connected by what we refer to as ‘partitions’. These tubes are farther away from the center of the system’s cross section, which makes the overall system much more stable than a conventional single telescopic boom system.
The Triple-Boom System has even more stiffness than suspended booms. The cables in a boom suspension system can bear traction alone, whereas the Triple-Boom System with its telescopic Power Tubes on either side can also absorb the kind of torsional forces (twisting) that can be caused by wind, rotary acceleration, and other factors. This is an important point, especially if long luffing jibs are being used.
The weight of the new Triple-Boom System is very similar to that of a conventional boom system, which was one of the key concerns of our designers. That allows the new 8-axle crane to comply with the 12 t per axle limit mandatory on many countries’ roads. But we didn’t compromise on the strength of a conventional steel structure, nor sacrifice our performance-optimized, fuel saving superstructure engine.
Innovative – yet tried-and-true
The new Triple-Boom System is essentially based on an optimum distribution of material and not on a highly complex new technology. For example: the separate telescopes in the new Triple-Boom System are extended and retracted using our familiar TADANO one-cylinder system. The way the telescopes are bolted is, in principle, the same as in other TADANO models, except that the telescopes of the two additional booms are now bolted together.
But because the three tubes are bolted up consecutively rather than simultaneously – first the Power Tubes then the telescopes of the main tube – the Triple-Boom System is extremely reliable in this respect as well.