Monge 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 sunk in 1942.
Characteristics
Monge 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
Monge was authorized under the 1925 naval program. She was laid down at Société Nouvelle des Forges et Chantiers de la Méditerranée at La Seyne-sur-Mer, France, on 17 May 1927 with the hull number Q144. Work on her was halted on 15 September 1927, but it later resumed and she was launched on 25 June 1929. She completed fitting out for her sea trials on 1 December 1929, successfully finished her trials on 26 February 1930, and completed fitting out on 10 August 1931. Declared complete on 30 January 1932, she was commissioned on 19 June 1932.
Service history
1932–1939
Among officers serving aboard Monge during the mid-1930s was François Drogou (1904–1940), later a recipient of the Order of Liberation.
Monge and her sister ship departed Toulon, France, on 16 December 1936 for a deployment to French Indochina in Southeast Asia, where they remained from January to March 1937. They then returned to Toulon, which they reached on 15 May 1937.
World War II
French Navy
At the start of World War II in September 1939, Monge was assigned to the 5th Submarine Division in the 3rd Submarine Squadron, 1st Flotilla, 2nd Squadron, based at Toulon. Her sister ships and Pégase made up the rest of the division
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. Monge and Pégase departed Toulon on 11 June and patrolled in the Mediterranean Sea south and southeast of Malta until 20 June 1940 to search for and attack Italian convoys making the passage between Italy and Tripolitania. The Battle of France ended in France's defeat and an armistice with Germany and Italy which went into effect on 25 June 1940.
Vichy France
After France's surrender, Monge served in the naval forces of Vichy France. In September 1940, the Vichy French Admiralty, with the concurrence of the Armistice Commission, decided to reinforce French naval forces in Southeast Asia by deploying four submarines to French Indochina. Two submarine divisions were formed for the deployment, the 8th at Toulon, consisting of the Redoutable-class submarines and , and the 22nd at Bizerte in Tunisia, consisting of Monge and Pégase . On 11 October 1940, Monge and Pégase departed Bizerte under escort by the bound for Oran in Algeria. There they rendezvoused with L'Espoir, Vengeur, and the tanker , which was to accompany the submarines on their journey, the tanker and the four submarines being designated the "Lot Group" for purposes of the voyage. Monge′s commanding officer, who also served as commander of the 22nd Submarine Division, took on the additional responsibility of commanding the Lot Group as a whole. After a stay at Oran that lasted from 13 to 16 October, Lot and the four submarines passed though the Strait of Gibraltar under the escort of the destroyers and under conditions of high tension with the United Kingdom and arrived at Casablanca in French Morocco on 18 October 1940 for a brief stopover. They then proceeded to Dakar in Senegal.
On 23 October 1940, the submarines got underway from Dakar to patrol off the Canary Islands. They encountered very heavy weather, and Pégase suffered damage to one of her diving planes. The submarines returned to Dakar on 28 October 1940. Subsequently, the submarines took turns conducting defensive patrols off Dakar.