The Pluviôse-class submarines were a group of 18 submarines built for the French Navy in the first decade of the 20th century. Before World War I, two were accidentally lost, but one of these was salvaged and put back into service. Four others were lost during the war and the survivors were stricken in 1919.
The Pluviôse class were built as part of the French Navy's 1905 building program to a double-hull design by Maxime Laubeuf.[1] The submarines displaced 404sp=usNaNsp=us surfaced and 553t submerged. They had an overall length of 51.12m (167.72feet), a beam of 4.96m (16.27feet), and a draft of 3.15m (10.33feet). differed from her sisters as she was built to test the hull shape planned for the following . She had an overall length of, a beam of and displaced on the surface and underwater. The submarines had a crew of 2 officers and 23 enlisted men.[2]
For surface running, the boats were powered by two 350PS triple-expansion steam engines, each driving one propeller shaft using steam provided by two Du Temple boilers. When submerged each propeller was driven by a 2300NaN0 electric motor.[3] On the surface they were designed to reach a maximum speed of 12kn and underwater.[1] The submarines had a surface endurance of 865nmi at and a submerged endurance of at .[4]
The first six boats completed (and) were armed with a single 450mm internal bow torpedo tube, but after an accident that lead to the sinking of in 1909, the tubes were removed from Pluviôse and Messidor. A ministerial order of 18 March 1910 added one to while she was still under construction, but the bow tubes were deleted from the rest of the class. All of the boats were fitted with six 450 mm external torpedo launchers; the pair firing forward were fixed outwards at an angle of seven degrees and the rear pair had an angle of five degrees. Following a ministerial order on 22 February 1910, the aft tubes were reversed so they too fired forward, but at an angle of eight degrees. The other launchers were a rotating pair of Drzewiecki drop collars in a single mount positioned on top of the hull at the stern. They could traverse 150 degrees to each side of the boat. The Pluviôse-class submarines carried eight torpedoes; those with bow tubes carried their reload in the torpedo compartment.[5]
| Q68 | Arsenal de Toulon | 1906 | 30 October 1909 | 1 November 1910 | Stricken, 12 November 1919 |
| Q66 | Arsenal de Rochefort | 19 May 1909 | 1 February 1910 | Stricken, 1 December 1919 | |
| Q76 | 14 October 1909 | 10 September 1910 | |||
| Q54 | Arsenal de Cherbourg | 18 October 1908 | 16 June 1909 | Sunk in collision with British armed boarding steamer, 2 August 1918 | |
| Q65 | Arsenal de Rochefort | 16 June 1908 | 22 February 1911 | Torpedoed by Austro-Hungarian destroyers, 5 February 1915 | |
| Q58 | Arsenal de Cherbourg | 13 November 1909 | 29 June 1910 | Stricken, 12 November 1919 | |
| Q69 | Arsenal de Toulon | 17 March 1910 | 14 January 1911 | Stricken, 1 December 1919 | |
| Q53 | Arsenal de Cherbourg | 7 December 1907 | 30 December 1908 | ||
| Q77 | Arsenal de Rochefort | 10 February 1910 | 13 October 1910 | ||
| Q56 | Arsenal de Cherbourg | 24 December 1908 | 30 November 1909 | Stricken, 12 November 1919 | |
| Q67 | Arsenal de Toulon | 31 December 1908 | 2 August 1910 | Rammed by Austro-Hungarian scout cruiser, 29 December 1915 | |
| Q64 | Arsenal de Rochefort | 4 January 1908 | 1 September 1909 | Unknown | |
| Q51 | Arsenal de Cherbourg | 27 May 1907 | 5 October 1908 | Sunk in collision, 26 May 1910. Raised and repaired. Stricken, 12 November 1919 | |
| Q55 | 26 September 1908 | 16 June 1909 | Sunk in collision with, 29 April 1918 | ||
| Q57 | 3 July 1909 | 13 July 1910 | Stricken, 12 November 1919 | ||
| Q59 | 7 July 1910 | 4 February 1911 | Sunk in collision with, 8 June 1912 | ||
| Q52 | 15 September 1907 | 5 October 1908 | Stricken, 1 December 1919 | ||
| Q75 | Arsenal de Rochefort | 18 June 1909 | 15 March 1910 | ||
The Pluviôse class were acknowledged to be good sea boats and saw action throughout the First World War on patrol and close blockade duty. Of the eighteen built, five were lost.One was accidentally lost prior to the war, in 1912. Two others, Floréal and, were lost accidentally during the conflict, while and were lost in action.[1]