The Evolution of Tunnel Boring Machines
15th July 2024
A common way of building a tunnel today is with a tunnel boring machine (TBM), particularly in urban areas where other construction methods such as drill-and-blast or cut-and-cover would be too disruptive. Of the 89 transit projects around the world that required tunneling in a dataset compiled by Britain Remade, 80 of them used TBMs. But tunnel boring machines are a comparatively modern construction technology. The first successful rock tunneling machines weren’t invented until the 1950s, and into the late 1960s most tunneling was done using other construction methods. But as TBMs have improved, they have increasingly been the method of choice for tunneling through a wider variety of ground conditions. And while many construction tasks have resisted automation and mechanization, tunneling machinery has steadily gotten more automated, to the point where a modern TBM is akin to a mobile factory that burrows through the earth and constructs a tunnel behind it.