The Military Fortress of Chillon – A 20th-century fortress (1941–1994) 4/5
Behind the medieval castle of Chillon, another monument dominates Lake Geneva: the military fort of Chillon. Built in 1941–1942, this artillery and infantry fort became the western gateway to Switzerland's national redoubt. For more than fifty years, it guarded the passage between the plateau and the Chablais region before being decommissioned in 1994. Discover the history of this super-fortress, from its construction to its transformation into a museum.
A long-standing project: from 1862 to 1939
The idea of fortifying the Chillon Pass dates back to the 19th century. In 1862, a study by Colonel Aubert proposed blocking the Simplon route at Chillon, recognizing the strategic value of this “obligatory passage” between Lake Geneva and the Vaud Pre-Alps. This site, which had been fortified since the Middle Ages, was seen as a key point for controlling communications between northern and southern Switzerland.
On the eve of World War II, Switzerland strengthened its defense network. In 1939, the first field fortifications were erected in the gardens of Chillon Castle, marking the beginning of the site's modern militarization. The Chillon artillery fort was designed as a modern structure, integrated into the Chillon barrage position, which included a dozen infantry structures, road barricades, anti-tank obstacles, and several mined structures.
Construction and commissioning (1941–1942)
Work on the Chillon artillery fort began on January 1, 1941, at the start of World War II. The structural work was completed in mid-1941, and the fort was handed over to the Swiss army in 1942. It was occupied for the first time on August 28, 1942, by the 9th Fortified Artillery Company, which in 1943 became the II/4 Fortified Artillery Company, subordinate to Fortified Group 4 (Fort Champillon) and Fortified Regiment 19.
The fort is designed as an artillery and infantry fort, responsible for guarding and defending the north-south passage at Chillon, in order to ensure readiness for the mobilization of Mountain Brigade 10, whose main troops are stationed in the Saint-Maurice region. It forms the western gateway to the Swiss national redoubt, a deep defense system designed to make the territory impregnable in the event of invasion.
Weapons and organisation (1942–1978)
When it was built, the Chillon artillery fort was equipped with two 7.5 cm anti-tank guns on special Giovanola mounts for direct fire (casemates C5 and C7), and two 7.5 cm anti-tank guns on special Giovanola mounts for artillery fire (casemate C8). These guns were replaced in 1962 by 9.5 cm anti-tank guns on pivot mounts, and the 7.5 cm guns in casemate C8 were removed in 1978 when the mission changed.
The fort also has five 11 machine guns (water-cooled), replaced in 1972 by 51 fortified machine guns, as well as 19 25 submachine guns, replaced by 6 57 automatic rifles. The garrison, consisting of approximately 131 men, is housed in gas-tight quarters, with a communications center and an equipment room.
External defense is provided by elements of the 88th Infantry Regiment (one section) and by the II/4 Fortified Company, which occupies seven infantry forts and the Porte du Scex and Fenalet fortifications. The fort is also connected to a barrage position comprising mined structures (OMI) on the road and the railway embankment, as well as a mined bridge over the Rhône.
Transformation and end of the artillery mission (1960–1978)
In 1960, the fort was renovated and expanded: the entrance along the road was moved further south (near the current bus stop), and a new ammunition store was built in accordance with the latest standards. This modernization was part of the adaptation of Switzerland's fortified network to the tactical and technological developments of the Cold War.
In 1978, the fort lost its artillery role: the 7.5 cm guns in casemate C8 were removed, and the structure was no longer considered an artillery fort, but solely an infantry fort. The administrative and tactical subordination changed: the 55th Fortifications Company (cp ouv 55) was created and occupied the Chillon fort, as well as the aforementioned forts and nine infantry forts at the Grande Eau strongpoint, until 1994.
Final years and decommissioning (1978–1994)
From 1978 to 1994, the fort of Chillon was used as a military fortification, occupied by the 55th Engineering Company, subordinate to the 5th Infantry Regiment. It continued to play a defensive role in the Chillon position, protecting access to the Chablais region from the plateau (and vice versa).
The Army 95 project, which radically reformed the Swiss army at the end of the Cold War, sealed the fort's fate. The Fort de Chillon was used as a military fortification until 1994, when it was declassified as a “secret defense” site. This date marked the end of more than fifty years of military service for this 20th-century fortress.
Sources
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Article « Fort de Chillon » sur le site de l’association Léman Sans Frontière, 2024.
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Fiche « A390 Fort d’artillerie de Chillon » sur le site FortLitroz, 2021.
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Article « Fort de Chillon » sur le site Notrehistoire.ch, 2023.
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Article « Villeneuve (VD) » dans l’Histoire de la Suisse (HLS-DHS-DSS), 2017.
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Site officiel de la ville de Villeneuve (VD), section « Histoire ».
5 Articles in this series:
The Military Fortress of Chillon – A 20th-century fortress (1941–1994) 4/5
Chillon and its region from 1900 to 1995 – Heritage, tourism, and memory 5/5