Chinese engineers have built a 17,000-ton swing bridge in the Hubei province capital of Wuhan in order to ensure that a high speed railway line could continue to operate during the construction of an elevated motorway.
The bridge was built to serve as the key section of a huge overpass in the Hubei province capital of Wuhan, passing directly over a major high speed railway line.
The mammoth overpass section was first built separately by Chinese engineers at a site adjacent to the high speed railway line, before being hoisted onto a 15-metre high axis at right angles to the rest of the elevated motorway.
The section was then deftly swivelled into its correct alignment by engineers, covering 106 degrees in the space of just 90 minutes.
Swing bridges are essentially movable bridges that are held in place by a vertical locating pin and a support ring, which enables the structures to swivel around horizontally.
The construction of the overpass marks the first occasion that this sophisticated engineering technique has been employed in modern China.
Because the primary structural support bears aloft the bridge section either at or close to its centre of gravity, no counterweights are required to facilitate movement, which makes swing bridges significantly lighter than other moveable bridges structures.
Swing bridges are most commonly used to support roads or rail lines that pass over rivers or canals at right angles, enabling trains or automobiles to traverse the water feature as well as boats go past the bridge by alternating the alignment of its span.
In the case of the Wuhan overpass section, however, the swing bridge has been employed as a one-off construction technique in order to avoid disrupting the high speed railway line which is situated beneath the elevated motorway and which was deemed too critical a transportation route to be temporarily closed.
The Chinese debut of this ingenious building method certainly provided passengers travelling on the high speed line with a stunning spectacle. One photo captured the moment that a high-speed train passed almost directly beneath the overpass as it was meticulously rotated into place by engineers.