France Gros Ouvrage de Rochonvillers, Maginot Line (visited 05/2017)

Andy · Jun 18, 2017

Description & History:

Ouvrage Rochonvillers is one of the largest of the Maginot Line fortifications. The gros ouvrage or large work was fully equipped and occupied in 1935 as part of the Fortified Sector of Thionville in the Moselle. Rochonvillers saw little action during World War II, but due to its size it was repaired and retained in service after the war. During the Cold War it found a new use as a hardened military command center, first for NATO and then for the French Army.

Rochonvillers was considered an early priority for construction, and as such went through several concepts in early design while the overall concept of the Maginot Line was being investigated. It was initially proposed in 1926 as a single massive fort shielding two artillery turrets in the rear. The next concept envisioned a closely grouped arrangement of works, four peripheral units around a turreted artillery block., located somewhat to the south of the present installation. A third iteration was termed the "village", a very large and expensive concept that was opposed by the residents of Rochonvillers. The fourth version was described as a fort palmé (or palmate), based on the ideas of Colonel Tricaud, first published in the Revue du Génie in 1917. The fort palmé proposed a dispersed set of fortifications fanning out from a central subterranean trunk which would contain barracks, utilities and ammunition magazines. This concept was adopted for the entire Line, with the strong support of Marshal Philippe Pétain, in late 1927. The Rochonvillers site was surveyed by CORF (Commission d'Organisation des Régions Fortifiées), the Maginot Line's design and construction agency, in 1929. Work by the contractor, Campernon-Bernard, began the next year, and the position became operational in 1935, at a cost of 123 million francs, the third most expensive ouvrage in the Northeast.

Rochonvillers covers an unusually large area. The combat blocks are connected to each other and to the subterranean barracks, magazines and entries at the rear by underground galleries at an average depth of 30 meters (98 ft). The locations of the entrances in a ravine allowed a relatively short inclined descent to the gallery complex. Stairs, ammunition hoists and chutes for spent casings rise to the surface at each block. The central utility plant or usine is just inside the personnel entry. Rochonvillers, as one of the largest ouvrages, was given a large "M1" magazine some distance in from the munitions entrance, an arrangement would be useful for a command post in later years. A large barracks is located at the junction of the personnel and munitions galleries.

The 1940 manning of the ouvrage under the command of Commandant Guillemain comprised 756 men and 26 officers of the 169th Fortress Infantry Regiment and the 151st Position Artillery Regiment. The units were under the umbrella of the 42nd Fortress Corps of the Third Army, Army Group 2. Peacetime quarters for the garrisons of Rochonvillers and Molvange were at the Camp d'Angevillers.

Rochonvillers did not see significant action in the Battle of France in 1940, nor in the Lorraine Campaign of 1944. The Germans in 1940 largely bypassed the area, advancing along the valley of the Meuse and Saar rivers, threatening the rear of the Thionville sector. An order to fortress troops by sector commander Colonel Jean-Patrice O'Sullivan to prepare for withdrawal on 17 June was reversed by O'Sullivan. On 21 June a 75mm gun in Block 5 exploded, killing one gunner and seriously wounding another. The gun position has never been repaired.[30] Rochonvillers was bombarded by heavy artillery on 22 June, with a projectile penetrating and exploding in Block 5. On June 30, 1940, the troops of the 169th RIF were ordered to evacuate their positions by the French command, seven days after the 22 June 1940 armistice.

The occupying Germans used Rochonvillers' barracks and magazine areas as troop quarters. After its occupation by the Americans in 1944, the Americans used some of the turrets and cloches in Blocks 5, 6 and 7 for experiments with armor-piercing weapons, in preparation for their assault on the Siegfried Line.

In the 1950s the French government became concerned about a possible invasion by the Warsaw Pact through Germany. A number of the larger ouvrages were selected to form defensive ensembles or môles around which a defense might be organized and controlled. Rochonvillers was chosen in 1951 to become the center of the môle de Rochonvillers, in company with Molvange and Bréhain, and later Immerhof. Block 5 was re-equipped with 105mm and 135mm guns and 12.7mm machine guns, while the 135mm turret of Block 6 was repaired with parts from the turret from Four-à-Chaux. Repairs to waterproofing and tunnel lining were undertaken at this time. By 1956 the ouvrage was restored to its original state, apart from the renovations to Blocks 5 and 6.

With France's acquisition of nuclear weapons in 1960, the Maginot fortifications began to be viewed as an expensive anachronism. Funding was provided for maintenance, but for little more. The Maginot Line, while obsolete in terms of its armament, was viewed as a series of useful deeply buried and self-sufficient shelters in an era of air power and nuclear weapons. In 1960 the French Army initiated inquiries among the other French forces and among NATO members concerning the use of Maginot fortifications as storage depots or as command centers. In 1961, after discussions with the Americans and West Germans, Rochonvillers, Molvange and Soetrich were placed at the disposal of NATO. Rochonviller's main magazine, with its two entries and circulation loop crossed by five galleries, was made into a wartime command center for the NATO Central Army Group (CENTAG) (normally located at Fontainebleau) at a cost of 380 million francs. Rochonvillers functioned in this role until 1967, when France withdrew from NATO's integrated command structure. The command center is located close to and between the personnel entry and the munitions entry, with connections to each. It is more than a kilometer from the command center to the main combat blocks via the main underground gallery.

CENTAG's headquarters were moved to Brunssum, the Netherlands, where the deactivated Hendrik coal mine was available for use. In 1971 the names of the Maginot ouvrages were declassified by the French military. At the same time, Rochonvillers was demoted from a fortified position of the first rank to a lower status, foreshadowing a general divestment of the Maginot Line's function as a fortification.

After deactivation in 1967, Rochonvillers was renovated in 1980 as the French First Army's hardened command center. Work included replacement of the ventilation and filtration system and construction of a blast wall a short distance in front of the main entry. The installation was planned to house 500 people for an extended period, immune to the effects of electromagnetic pulse, radioactivity, chemical weapons and all but a direct hit with a nuclear weapon. The electrical generating plant and underground barracks were renovated. Most exposed concrete faces in the entry blocks were covered with earth as a blast shield, while the combat blocks themselves were used only as antenna mounts. The peacetime 1st Army headquarters was moved from Strasbourg to Metz in 1989, in part to be closer to Rochonvillers. From 1981 to 1998 the command center was maintained by a small staff in between full-scale exercises. With the disappearance of the Soviet threat, the command center was deactivated.

Visited with @The-Raw, @Maniac, @extreme_ironing and Elliot5200.

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