French submarine Pluviôse

Pluviôse (Q51) was the name ship of her class of 18 submarines built for the French Navy (Marine Nationale) in the first decade of the 20th century.

Design and description
The Pluviôse class were built as part of the French Navy's 1905 building program to a double-hull design by Maxime Laubeuf. The submarines displaced 404 t surfaced and 553 t submerged. They had an overall length of 51.12 m, a beam of 4.96 m, and a draft of 3.15 m. Their crew numbered 2 officers and 23 enlisted men. For surface running, the boats were powered by two 350 PS 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 230 PS electric motor. On the surface they were designed to reach a maximum speed of 12 kn and 8 kn underwater. The submarines had a surface endurance of 865 nmi at 11.6 kn and a submerged endurance of 70 nmi at 2.8 kn.

The first six boats completed, including Pluviôse, were armed with a single 450 mm internal bow torpedo tube, but after an accident that lead to the sinking of their sister FRENCH SUBMARINE Fresnel in 1909, the tubes were removed from Pluviôse and her sister Messidor. 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.

Construction and career
Pluviôse, named for the fifth month of the French Republican calendar, was ordered on 26 August 1905 from the Arsenal de Cherbourg. The submarine was laid down in 1906, launched on 27 June 1907 and commissioned on 5 October 1908.

On the afternoon of 26 May 1910 Pluviôse was cruising off Calais when she was involved in a collision with the packet boat Pas de Calais. Pluviôse sank with the loss of all hands, 27 men. The vessel was later raised and repaired, and returned to active service. Her captain at the time of the accident Maurice Callot, was later honoured by having a submarine named after him.

Pluviôse was stricken in 1919 and used for compression tests. She was eventually sold for scrap in 1925.