To this end, the two cities were specially served by the Kanonenbahn Berlin - Metz, a strategic railway line.

From 1899, the Schlieffen plan of the German General Staff designed the fortifications of the Moselstellung as like a lock for blocking any advance of French troops in case of conflict.

[4] This concept of a fortified line on the Moselle was a significant innovation compared to the Système Séré de Rivières developed by the French.

It offered great comfort for the time -- central heating, toilets, a bread oven, an electric plant, a telephone and running water.

A network of tunnels provided connections between the various points of the fortified group, covering an area of over 40 ha.

Its comfort and its technological prowess impressed the French General Staff, who drew valuable lessons from it for the construction of the future Maginot Line.

From June 1942, a thousand skilled workers took shifts turns in the fort, which quickly became a true underground factory.

[11] When hostilities resumed in October after a month of rain, the soldiers of the 462th Volks-Grenadier-Division still firmly hold their positions even if the supplies are more difficult, because of the artillery and the frequent bombings.

[12] On November 9, 1944, the Air Force sends no less than 1,299 heavy bombers, B-17s and B-24s, and drops 3,753 tons of bombs, and 1,000 to 2,000 books on the fortifications and strategic points in the combat zone of IIIrd army.

[15] The objective of the German staff, which was to stall the US troops at Metz for the longest possible time before they could reach the front of the Siegfried Line, is largely achieved.