French submarine Fresnel (Q143)

Fresnel was a French Navy of the M6 ​​series commissioned in 1932. She participated in World War II, first on the side of the Allies from 1939 to June 1940, then in the navy of Vichy France until she was scuttled at Toulon in November 1942. She was never again seaworthy, but the Italians seized her and refloated her, and the Germans later took control of her. She was sunk in March 1944.
Characteristics.
"Fresnel" was part of a fairly homogeneous series of 31 deep-sea patrol submarines also called "1,500-tonners" because of their displacement. All entered service between 1931 and 1939.
The "Redoutable"-class submarines were long and in beam and had a draft of . They could dive to a depth of . They displaced on the surface and underwater. Propelled on the surface by two diesel engines producing a combined , they had a maximum speed of . When submerged, their two electric motors produced a combined and allowed them to reach . Also called "deep-cruising submarines", their range on the surface was at . Underwater, they could travel at .
Construction and commissioning.
"Fresnel" was ordered under the 1925 program. Laid down at Ateliers et Chantiers de Saint-Nazaire Penhoët in Saint-Nazaire, France, on 7 July 1927 with the hull number Q143, "Fresnel" was launched on 8 June 1929. While fitting out, she suffered serious damage when, on during a test at Brest, France, in which her diesel engines were run in reverse, the control system for her stern diving planes broke, allowing them to move in a way that damaged both of her propellers and caused significant damage to her engines. After repairs and successful completion of her sea trials, she was commissioned on 22 February 1932.
Service history.
On 5 January 1933, a fire broke out aboard "Fresnel" while she was at Toulon, France.
In 1933 and 1934, "Fresnel" conducted a scientific cruise to collect gravimetric measurements in the northwestern Mediterranean Basin. During the cruise, a French hydrographic engineer made 30 gravimetric measurements.
On 5 June 1937, a reorganization of the French Navy′s submarine force took place which also called for French submarines to conduct long cruises to test the endurance of their personnel and equipment. Orders called for "Fresnel" and her sister ships , , and to conduct such a cruise to Argentina.
World War II.
French Navy.
At the start of World War II in September 1939, "Fresnel" was assigned to the 3rd Submarine Division of the 3rd Submarine Squadron of the 1st Flotilla of the 2nd Squadron, based at Toulon. Her sister ships "Achéron", , and made up the rest of the division. She initially patrolled off the Canary Islands, where German merchant ships — which the Allies suspected of serving as supply ships for German U-boats — had taken refuge at the beginning of the war. During these patrols, her crew boarded the Portuguese ocean liner and took prisoner eight Germans they found on board. In December 1939, "Fresnel" joined "Achéron", "Agosta", "Bévéziers" and their sister ships and in forming a patrol line to search the central Atlantic Ocean for the German supply ship , but "Fresnel" was low on fuel and soon had to proceed to Casablanca in French Morocco to refuel.
On 29 December 1939, "Fresnel" was patrolling in the Canary Islands when she stopped the British steam cargo ship by firing a warning shot, allowing "Patriot" to proceed after determining that she was not a German blockade runner. As of 6 February 1940, she and the other submarines of her division were based at Casablanca and still assigned to patrol in the Canary Islands, but "Fresnel" later was transferred to Bizerte in Tunisia. 
German ground forces advanced into France on 10 May 1940, beginning the Battle of France, and Italy declared war on France on 10 June 1940 and joined the invasion. On 10 June 1940, "Fresnel" got underway from Bizerte, and she patrolled between Bizerte and Cape Serrat from 11 to 13 June 1940 to defend the coast of Tunisia against a possible Italian amphibious landing. On 24 June 1940, she was sent along with her sister ships and to patrol in the Mediterranean Sea south of Sardinia. The Battle of France ended in France's defeat and an armistice with Germany and Italy which went into effect on 25 June 1940. "Fresnel" was recalled from her patrol that day.
Vichy France.
After France's surrender, "Fresnel" served in the naval forces of Vichy France. She spent time at Toulon, then on 16 April 1941 departed Toulon in company with "Actéon" and their sister ship to transfer to Casablanca. Soon after arriving at Casablanca, "Fresnel" and "Actéon" got back underway on 22 April 1941 for a training cruise along the coast of French Morocco. They called at Safi on 23 April, at Agadir from 24 to 25 April, and at Mogador from 26 to 28 April before returning to Casablanca on 29 April 1941.
By 1 January 1942, "Fresnel" was assigned to the 5th Submarine Division at Casablanca along with "Actéon", "Henri Poincaré", and "Pascal". On 25 September 1942, she began a stay at Fedala, French Morocco, which lasted until "Actéon" relieved her on 13 October 1942. 
In November 1942, the submarines of the 5th Submarine Division received orders to proceed to Toulon to undergo a major overhaul, but "Fresnel" and "Actéon" were still in French North Africa at Oran in Algeria when Allied forces landed on the coast of North Africa in Operation Torch on 8 November 1942. As soon as the French detected the landings at Arzew, Algeria, "Fresnel", "Actéon", and the submarine received orders at 02:50 on 8 November to get underway from Oran to oppose the landings. A British shell damaged "Fresnel" slightly just after she cast off, and she survived the detonation of five depth charges without further damage. At 10:45, as she prepared to fire a spread of five torpedoes at the British light cruiser , the premature launch of one of her torpedoes gave away her position. "Jamaica" sighted and evaded her torpedoes, and "Fresnel" subsequently survived three days of gunfire and depth-charging by counterttacking British warships, which pursued her all the way to the limits of Spanish territorial waters. After finally breaking contact with them on 11 November 1942, "Fresnel" found herself without further orders, so on her own initiative she headed for Toulon, which she reached on 13 November 1942.
"Fresnel" was in drydock in the Missiessy Docks at Toulon when Germany and Italy occupied the Free Zone () of Vichy France on 27 November 1942, and she was among the French vessels scuttled at Toulon to prevent their seizure by Germany when German forces entered Toulon that day.
Italy and Germany.
The Germans seized "Fresnel" and handed her over to the Italians, who refloated her on either 28 or 29 January 1943, according to different sources, planning to refit her. She was sunk again on 19 February 1943, but the Italians refloated her again on 4 May 1943. The Germans seized her when Italy surrendered to the Allies and switched to the Allied side in accordance with the terms of the Armistice of Cassibile on 9 September 1943. Allied aircraft sank her for the final time on 11 March 1944.