154 - ◊Chagnaud Archives: The History of Major Construction Projects Up for Auction

◊Chagnaud Archives: The History of Major Construction Projects Up for Auction Two watercolor drawings, each over three meters long, depicting a passage under the Seine: these pieces are among the 18 lots from the Chagnaud company archives that we are offering at auction. Drawings, photographs, awards, and a technical library shed light on a history that extends beyond that of the company itself: the history of the construction projects that transformed Paris and the surrounding regions. From Metro Line 4 to the Éguzon Dam in the Creuse department, from the Marseille-Rhône Canal to the Clichy collector, these documents invite us to view public works as a heritage to be understood and passed on. The Chagnaud Company The story begins in Guéret in 1860, when Hippolyte Chagnaud founded his masonry company. His son Léon, trained at the École des Arts et Métiers, took over the company in 1891 and developed its expertise in underground construction. The archives offered for sale reveal the methods, equipment, and work of the builders behind each structure. Beneath the Seine and Beyond How do you build beneath a river? The drawings of Line 4 illustrate the principle of compressed-air caissons. The two large profiles show the work in progress, followed by the completed structures, while the cross-sections reveal their internal structure. Technical Drawings: A Different Perspective on Public Works The drawings we present combine the precision of architectural drafting with the finesse of pen and the nuances of watercolor. This is what makes them so appealing to collectors: they bring together, on a single sheet, the history of a construction project and the expertise of a draftsman. The Archives Construction site photographs, awards, and the technical library round out this collection. Photographs of Saint-Michel adorned the company’s offices; specialized journals and books enriched its documentation. These items thus preserve the legacy of knowledge, achievements, and professional pride of a civil engineering firm. They give the archives their status as industrial heritage. By offering these 18 lots at auction, we hope to share this legacy with a new audience. Construction professionals, institutions, collectors, and enthusiasts of the history of Paris, Marseille, and major public works projects may find a connection to a trade, a region, a place, or a familiar structure. These documents will continue their story with new owners, while preserving their provenance: that of the Chagnaud company and the construction projects it helped bring to life. Purchasers of lots from the Chagnaud archives will receive a copy of the book written by Arnaud BERTHONNET, *Chagnaud Construction: History and Rebirth of a Great Builder*.