Louis Joubert Lock

The Louis Joubert Lock (French: Forme Ecluse Louis Joubert) also known as the Normandie Dock, is a lock and major dry dock located in the port of Saint-Nazaire, in Loire-Atlantique northwestern France.

Owned by the Port authority of Nantes-Saint-Nazaire and not the ship building company Chantiers de l'Atlantique, its strategic importance as a major naval construction and maintenance asset since its completion in 1934, resulted in it becoming the main target of the British Army Commando raid of 1942, the St. Nazaire Raid, to stop German battleships such as Tirpitz from accessing maintenance facilities in the Atlantic Ocean.

The lock has two major functions:

As an historic major seaport on the western edge of the Atlantic, the closest for ships coming from the western Atlantic to France, Saint-Nazaire had played a major part in World War I as a disembarkation point for United States Army troops. The US Army had undertaken various development projects around Saint-Nazaire, including the construction of a refrigeration plant in the docks for storage of imported meat and dairy products.

At the end of the First World War, the Port Authority of Saint-Nazaire envisaged the construction of a third basin to mitigate the port's then lack of large scale ship facilities. However, due to the post-war recession and resultant down turn in shipping traffic, the idea was abandoned. However, scale problems encountered during the construction of the SS Île de France, and the opportunity to build the proposed super passenger liner which would become the SS Normandie, resulted in a reassessment of the project.

...
Wikipedia