Time limit and costing has always lead humans to wonder about ways of fast works especially to problems associated with the capacity of existing roads and highways. One such model is in operation in China at present. The machine is called SLJ900/32 or Segmental Bridge Launching Machine – SLJ900/32 bridge girder erection monster machine.
The SLJ900/32 is currently in active use in China for the construction of large and high rail viaducts, most notably between Chongquing and Wanzhou in the province of Sichuan. The SLJ900/32, manufactured by the Beijing Wowjoint Machinery Company and designed by the Shijiazhuang Railway Design Institute, weighs in at a mighty 580 tonnes, is 91 metres long and 7 metres wide.
How it works:
The colossal machine offers a totally new way to complete large bridge projects without the need for expensive and complex scaffolding and framework structures.
After picking up the beam needed from its point of origin, the SLJ900/32 will drive to the pillars of the bridge and lower a pneumatic support structure which essentially anchors the machine to the first pillar, allowing it to extend itself out to the second pillar. From here it moves on to a third, depositing the beam as it does so. To watch it in action is perhaps the easiest way to fully understand it’s efficient, fluid and fuss-free operation.
The machine transports itself, via its set of 64 wheels, which are split into four sections consisting of 16 wheels each. As each section is capable of rotating 90 degrees, the SLJ900/32 can move sideways in order to facilitate easy pick-ups of beams.
Whereas traditional crane-based methods of bridge construction have necessitated that beams and other segments come in sections usually just a few metres long, which are then fixed together, the SLJ900/32 is able to utilize beams that are specially prepared to be full length. Expansion joints are used to connect these prefabricated parts.
At present the machine is said to be capable of up to 730 spans with about 40 percent of the products being able to push this total up to 1000 before reaching the end of its lifespan which averages at four years.
Design specification
It is designed to build long bridges consisting of a large number of spans. The works on moving, installing, and securing the finished segments of the bridge to the pre-installed supports are on the shoulders of this machine. It should be noted that the construction of a bridge with the help of such a machine still requires manual labor, but its quantity and severity are incommensurably smaller in comparison with the technologies used in the past century.
The SLJ900/32 bridge girder erection mega machine, the length of which is about 91 meters (300 feet), the width is 7.4 meters (24 feet), the height is 9 meters, and the weight is about 580 tons, is capable of laying 700-750 bridges’ spans during its “life” although more than 40 percent of such machines were able to lay move than 1000 bridges’ spans, each weighing from 800 to 950 tons.
Info- heavy world, fircoft.com