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The Zipper truck system, known as Arch-Lock, is basically a mobile arch form work that, when used with precast concrete wedges, creates an instantly strong system.
The system is used a lot in mining, but has also been used for highway and railway over/underpasses, tunnels, hurricane/tornado shelters, wine cellars, culverts, ditches, and creek crossings. One of the other cool things about it is that it can be dismantled and re-assembled to be used on another project or moved.