During the 19th century, the naval dockyards underwent a transformation as the fleet of sailing ships was replaced by motorised vessels. The sites were industrialised and gradually specialised. In 1865, the naval dockyards in Brest became exclusively military, with the closure of the Penfeld port to commercial vessels. In 1898, after specialising in the building of vessels with propellers rather than sails, the shipyards in Cherbourg were tasked exclusively with the construction of submarines. Finally, in 1927, a decree definitively laid out the missions of the various naval dockyards: Brest and Lorient were tasked with the construction of large vessels, Cherbourg with building submarines, while Toulon, Bizerte and Saigon took charge of the maintenance of the fleet. This rationalisation of the roles of the naval dockyards was accompanied by technical and military innovations and the production of vessels at a higher pace, against the backdrop of an arms race and colonisation. In 1858, , the first ocean-going battleship in the world sailed out of the dockyards in Toulon. The 1860s saw the arrival of the first torpedo boats and military submarines, with the launch of in 1863. The technical problems experienced by this first-ever motorised submarine meant that it remained a prototype rather than an operational war vessel. But it did open the way for the construction of in 1886 and Le Narval in 1899, which were the first operational torpedo submarines in history. The production of heavy surface vessels was also stepped up in the 1910s. Several battleships were built before the start of the First World War, and the fleet was strengthened by the 35,000-ton in 1939. Reorganisation of activities In 1946, a review of the French naval dockyards completed the attributions of the various sites announced in the 1927 decree. Brest was tasked with the production and repair of large vessels, Lorient with the construction of medium-sized vessels, Cherbourg with submarines and Toulon with repairing and maintaining the fleet. Amongst the inland sites, Indret took over the vessel propulsion activities, Ruelle the construction of guns, large parts and electronics, Saint-Tropez the production of torpedoes and Guérigny the construction of naval chains and anchors. Five sites are located overseas: Mers el-Kébir, Bizerte, Dakar, Diego-Suarez and Papeete. Until 1961, the French navy maintained and repaired its fleet itself, through the Directions des Constructions et Armes Navales (DCAN) in the naval dockyards. The engineers working in the DCANs were officers