page_title: Fortified position of Liège
section_title: Armament
hierarchical_section_title: Fortified position of Liège / Design and construction / Armament
caption_attribution_description: English: Battle of Cambrai, November-december 1917 A German howitzer captured by the 1st/7th Gordon Highlanders, 51st Division at Flesquieres in its emplacement. 24 November, 1917. (2015 Comment: This is a "21 cm Turmhaubitze M 1891" as it was made by Krupp for the belgian forts Liege, Namur and Antwerp, converted to field guns by the Imperial German Army after they had captured the forts.)
context_page_description: The fortified position of Liège was established following World War I by Belgium to block the traditional invasion corridor from Germany through Belgium to France. The Belgian experience of World War I, in which the Belgian Army held up the invading force for a week at Liège, impeding the German timetable for the conquest of France, caused Belgium to consider a refined defence strategy. Belgium upgraded the existing fortifications of Liège and extended them onto the Herve plateau closer to Germany, using the most advanced fortifications available to Belgian military technology. However, in 1936, Belgium's neutrality was proclaimed by King Leopold III of Belgium in a vain attempt to forestall another conflict, preventing France from being able to make active use of the Belgian defences and territory in the forward defence of France. At the outbreak of World War II, Belgium's defences had to resist alone until France could advance into Belgium after neutrality failed. Again the fortifications could not hold the Germans.
context_section_description: The Meuse forts were armed with a total of 171 gun turrets, whose manufacture, transportation, and installation costed ₣24,210,775 in total. They were made of steel and placed in a concrete well in the massif or main redoubt. A turret itself sat on top a set of rollers, allowing it to turn 360°, and moved up and down its well with tracks running the length of the well. While smaller turrets could completely retract into the fortress, larger-calibre guns could not because of the length of their barrels. A steel collar protected the lip of the turret well and prevented the displacement of the turret in case the nearby concrete was damaged. In October 1912, a cycle of artillery tests held in Russia and attended by Belgian officials showed this not to be the case. 15 cm shells could jam the turret in place, while 28 cm shells could entirely dislodge them from battery.
  The turret and therefore the guns within were moved, aimed, and fired from within the turret. This was done either by an observer within the gun directly, or indirectly with the use of a graduated ring that showed 1/20ths of a degree. According to Brialmont's specifications, a gun turret could make a complete rotation in 1.5 minutes, and three rotations in five minutes. Once the right angle and elevation was found, a brake was engaged to hold the turret in place. Ordinance was hoisted in a basket with a manual elevator to the gun, which was fitted with a hydraulic recoil brake containing 80% glycerine and 20% water. The turret was kept under negative pressure using a manual ventilator to expel fumes from the gun and to keep fumes from incoming shells out of the fort. In case of a malfunction, a gun could be removed and replaced within a few hours. Munitions were held beneath the turrets in separate form and without cartridge casings for larger-calibre guns and in a complete shell for 5.7 cm guns. Every one of the Meuse forts' guns used black powder and were never modified to use a smokeless alternative.
  The smallest artillery employed in the Meuse forts was the 5.7-centimetre (2.2 in) Nordenfelt cannon, used to evaporate attacking infantry at close range. These were usually mounted on a wheeled triangular carriage but sometimes in turret form. In large forts, there were nine 5.7 cm guns in casemates – two in each gorge casemate, four in the head casemate, and one in the casemate guarding the entry ramp. In small forts, there were also nine 5.7 cm guns. Four were placed in gorge ditch casemates near the entrance, while another defended the ramp. Trapezoidal forts of either size had two of their nine 5.7 cm guns in the casemaste defending the fourth angle of the fort. Large forts had four 5.7 cm turrets, while small forts had three. These all contained a singe gun, crewed by six men, and exclusively fired grapeshot. The casemate guns were produced by Cockerill and Krupp, while the turret versions were manufactured by Gruson.
  The rest of a fort's arsenal was contained in turrets and the makeup of a fort's armament depended on its size. Large forts received a single 15 cm turret sporting two guns, two two-gun 12 cm turrets, and two one-gun 21 cm turrets. Small forts had two one-gun 12 cm turrets and a one-gun 21 cm turret. These were produced by Gruson, Creusot, Saint-Chamond, Ateliers de la Meuse, and Chatillon-Commentry. Additional guns were supplied by Marcinelle-Couillet, but only at the Fort de Boncelles and the large forts at Namur, and by Vanderkerhove, unique to Liège's large forts. All of the forts possessed a 60 cm searchlight in a turret produced by Ateliers de la Meuse.
caption: One of the former 21 cm turret guns converted to a field artillery piece.
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