Building bridges by hand is so twentieth century.
In China, the 300-foot Segmental Bridge Launching Machine is instrumental in the construction of long bridges. Although humans still appear to complete the actual fitting, the machine has assumed much of the heavy lifting responsibilities: it transports pre-cast concrete bridge segments into place to connect supports that have already been erected:
Bridge Design & Engineering reports that such machines have become commonplace throughout China over the past several decades. Originally, each machine had to be custom-designed for the bridge it was intended to construct.
“Launching machines are always customised to suit the specific bridge design, construction conditions, structural dimensions of beams and so on,” write Yabin Liu and Fuchun Yuan. “Even if a bridge project needs multiple launching machines, the supplier may design different erection solutions and the launching machines may vary in structure, operation and controls.”
In recent years, however, engineers have devised ways to make the machines more reusable. Thanks to technological and design advances, the majority of machines can be dissembled and customized for multiple projects. On average, a machine will erect more than 700 bridge spans throughout its life.
An accompanying animated short depicts even more of the bridge-building process: