- Source: SLJ900/32
The SLJ900/32 or otherwise known as the Iron Monster is a superheavy launching gantry and one of the largest and most ubiquitous in the world. At over 90 meters in length, the SLJ900/32 is also one of the world's longest terrestrial vehicles. It is built by the Beijing Wowjoint Machinery Company and designed by the Shijiazhuang Railway Design Institute.
Description
The SLJ900/32 as aforementioned, is 91 metres (299 ft) long, 7 metres (23 ft) wide, 9 m (29 ft 6 in) tall and weighs around 580 tonnes (640 short tons). It is a disproportionately long and slender vehicle which is needed as it is designed to construct bridges in a safe and efficient manner. Compared to conventional cranes which require clear land and is only able to lift a few meters of bridge material per-lift, the SLJ900/32 is capable of lifting an entire large segment of bridging material (some of which weigh around 800 to 950 tons) in a relatively compact manner without the hassle of interference such as trees or rocks.
Construction process is done via the vehicle carrying picking up a new pre-cast section of concrete all the way from the very edge of the bridge to the installation point underneath its "belly", where it will be connected to a predetermined pillar. Then, using a pneumatic structure, the machine is moored to the first pillar to extend to the second one, anchoring to it, and place the beam. The process would repeat itself until the bridge's foundations are completed.
The vehicle moves on a large 64x wheel drive system, which in itself is divided into four sections of 16 wheels each (forming two trucks, one at each end). Each of the sections can rotate up to 90 degrees that let’s the machine drive sideways for efficiency when picking up beams. The vehicle can maintain a top speed of 8 km/h (5 mph) unloaded, and 5 km/h (3 mph) carrying a bridge segment.
The operational life of each vehicle is capable of building up to 730 spans before retiring.
See also
Launching gantry
