Buschtunnel

The Aachen Buschtunnel consists of two parallel railway tubes that run beneath the Aachen Forest near the German-Belgian border. This line is of particular historical and infrastructural importance, as it serves international long-distance trains such as the Eurostar, the ICE International and the Nightjet, as well as regional trains. The older of the two tunnels was built between 1838 and 1843, making it the oldest railway tunnel in Germany still in use. At 691 meters long and with a maximum overburden of 45 meters, it passes through sandy soil. Over its long history, the tube has had to be renovated several times, among other things because of inadequate waterproofing and later because of damage to the sprayed concrete layer caused by smoke, frost and water.

To increase capacity and safety, a new single-track tunnel was built between 2004 and 2007, 25 to 45 meters south of the old structure. This 711-meter-long new tunnel is slightly curved and was built as part of a European rail project to increase train speeds on the route to Aachen Hauptbahnhof and the Belgian high-speed line. Before construction could begin, unexploded ordnance from World War II had to be cleared, as the area had been heavily bombed. The tunnel cuts through the fine-grained quartz sand of Hauset, with the groundwater table lying just below the tunnel floor.

After the new tunnel was completed, the old tube was temporarily closed and extensively renovated between 2009 and 2011. It received a new inner concrete lining, an escape route and modern lighting and fire protection systems. The old tube, which originally carried two tracks, was converted to a single, lowered track to enlarge the cross-section. Today, trains in each direction run through their own single-track tube. The entire stretch of line was upgraded to a top speed of 160 kilometers per hour (about 100 mph), which also required adjusting the track alignment and removing older crossing structures.