Renovating an underground railway system without weeks of construction and chaos caused by delays and diversions was previously unheard of. That is, until a unique concrete bolt emerged in Nuremberg.
The people of Nuremberg are proud of their underground system, which is among the most modern in Europe. The city, located in Bavaria, southern Germany, has the only underground network in Germany where two of the three lines operate automatically, without train drivers. Nuremberg trains travel the equivalent of the circumference of the earth twice each day, carrying more than one hundred million passengers per year.(…)
via The light at the end of the tunnel | Fastener + Fixing Magazine.