BBCTechnology

The mega-machines helping China link the world

China is creating a network of ambitious land- and sea-based transport links to connect its booming economy with those of Europe and Africa. And it’s wasting no time – designing incredible bespoke construction machines to get the job done fast.
President Xi Jinping’s ambitious Belt and Road Initiative (BRI), launched in 2013, aims to connect two-thirds of the world’s population across 70 countries through a network of land links (the “belt”) and sea routes (the “road”).
Officials talk about lifetime investments worth trillions of dollars, sourced from banks, participating countries and the Chinese government.
The scheme is not without controversy. Critics point out that it burdens poor countries with billions of dollars of Chinese debt, and dismiss it as a projection of Chinese foreign policy.
Nevertheless, evidence of the Belt and Road can already be seen in China and beyond, where a fleet of new machines is building railways at considerable speed.
Building bridges
How do you build high-speed railways quickly where large sections of the route must be suspended over valleys and canyons to avoid bends?
Enter bridge-building machine SLJ900/32 – locally nicknamed the Iron Monster.
The SLJ is an all-in-one machine capable of carrying, lifting and placing sections of track, connecting pillar with pillar by heavy stone blocks.
After laying each section, the 92m (300ft) vehicle – with the help of its 64 wheels – returns to collect another block. It then rolls forward over the part it has just laid to place another section.
Each wheel is in a fully rotating block of 16, meaning it can also move sideways.
Even with a full load, it can move at 5km/h (3mph), ensuring that the whole process is much quicker than traditional methods, which needed enormous cranes to be built on the ground.
At 580 tonnes, it is also much heavier than any of the railway traffic that will pass over the track it lays, meaning its bridges are made far stronger than necessary for rail traffic.
It has already contributed towards several high-speed rail projects, including a new link between Inner Mongolia and the rest of the country, propelling China towards its goal of 30,000km of high-speed rail by 2020.

Source: BBC

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