Surcouf was a large French gun-armed cruiser submarine of the mid 20th century. She carried two 203 mm guns as well as anti-aircraft guns and (for most of her career) a floatplane. Surcouf served in the French Navy and, later, the Free French Naval Forces during the Second World War.
Surcouf disappeared during the night of 18/19 February 1942 in the Caribbean Sea, possibly after colliding with the US freighter Thompson Lykes, although this has not been definitely established. She was named after the French privateer and shipowner Robert Surcouf. She was the largest submarine built until surpassed by the first Japanese I-400 class aircraft carrier submarine in 1944.
Design
The Washington Naval Treaty had placed strict limits on naval construction by the major naval powers regarding the displacement and artillery calibers of battleships and cruisers. However, no agreements were reached regarding light ships such as frigates, destroyers, or submarines. In addition, to ensure the country's protection and that of the empire, France started the construction of an important submarine fleet (79 units in 1939). Surcouf was intended to be the first of a class of three submarine cruisers; however, she was the only one completed.
The missions revolved around: Ensuring contact with the French colonies; In collaboration with French naval squadrons, searching for and destroying enemy fleets; Pursuing enemy convoys. Technical Details Ship dimensions Surcouf had a length of 110 meters (361 feet), a beam of 9 meters (29 feet 6 inches), and a draught of 7.25 meters (23 feet 9 inches). Her overall height was 15 meters (49 feet). She displaced 3,304 tonnes when surfaced and 4,304 tonnes when submerged. The submarine was rated for a test depth of 80 meters (260 feet) and carried a complement of 118 officers and men. Propulsion Surcouf was powered on the surface by two Sulzer diesel engines producing a total of 7,600 horsepower, driving two propeller shafts. When submerged, she switched to two electric motors delivering 3,400 horsepower. This allowed for a maximum surface speed of 18.5 knots (34.3 km/h) and a submerged speed of 8.5 knots (15.7 km/h). Her operational range was 10,000 nautical miles (19,000 km) at 10 knots, making her suitable for oceanic patrols. Armament Surcoufs main armament was a unique twin turret of 203 mm (8-inch) guns, a very large caliber for a submarine, exceeded only by HMS M1's 305 mm (12-inch) gun. The 8 inch caliber guns were the largest permitted under Article 12 of the Washington Naval Treaty for vessels not to be classed as a capital ship. The guns had a range of up to and could be fired only while surfaced. For close-in defense, she carried two 37 mm anti-aircraft guns and four 13.2 mm machine guns. Her torpedo armament included four 550 mm tubes in the bow and two turrets with a single 550 mm tube and two 400 mm tubes each on the stern. Surcouf also carried a Besson MB.411 floatplane in a watertight hangar, launched by catapult for reconnaissance and gunfire spotting.
Eight 550 mm and four 400 mm reloads were carried. The 203 mm Modèle 1924 guns were in a pressure-tight turret forward of the conning tower. The guns had a 60-round magazine capacity and were controlled by a director with a rangefinder, mounted high enough to view an horizon, and able to fire within three minutes after surfacing. Using the boat's periscopes to direct the fire of the main guns, Surcouf could increase the visible range to ; originally an elevating platform was supposed to lift lookouts high, but this design was abandoned quickly due to the effect of roll.Sous-marin croiseur Surcouf: Caractéristiques principales The Besson observation plane could be used to direct fire out to the guns' maximum range. Anti-aircraft cannon and machine guns were mounted on the top of the hangar.
Surcouf also carried a motorboat, and contained a cargo compartment with fittings to restrain 40 prisoners or lodge 40 passengers. The submarine's fuel tanks were very large; having enough fuel for a range and supplies for 90-day patrols. The first commanding officer was Frigate Captain (Capitaine de Frégate, a rank equivalent to Commander) Raymond de Belot.
The boat encountered several technical challenges: Because of the low height of the rangefinder above the water surface, the practical range of fire was with the rangefinder, increased to with sighting aided by periscope, well below the guns' maximum range of . The duration between the surface order and the first firing round was 3 minutes and 35 seconds. This duration would be longer if the boat were to fire broadside, which meant surfacing and training the turret in the desired direction. Firing had to occur at a precise moment of pitch and roll when the ship was level. Training the turret to either side was impossible when the ship rolled 8° or more. Surcouf could not fire accurately at night, as fall of shot could not be observed in the dark. The guns' ready magazines had to be reloaded after firing 14 rounds from each gun. To replace the floatplane, whose use was initially limited, trials were conducted with an autogyro in 1938.
Appearance From the beginning of the boat's career until 1932, the boat was painted the same grey colour as surface warships, but thereafter in Prussian dark blue, a colour which was retained until the end of 1940 when it was repainted with two tones of grey, serving as camouflage on the hull and conning tower.
Career Early career Soon after Surcouf was launched, the London Naval Treaty finally placed restrictions on submarine designs. Among other things, each signatory (France included) was permitted to possess no more than three large submarines, each not exceeding standard displacement, with guns not exceeding in caliber. Surcouf, which would have exceeded these limits, was specially exempt from the rules at the insistence of Navy Minister Georges Leygues,Croiseur sous-marin Surcouf, netmarine but other 'big-gun' submarines of this boat's class could no longer be built.
Second World War
In 1940, Surcouf was based in Cherbourg, but in May, when the Germans invaded, she was being refitted in Brest following a mission in the Antilles and Gulf of Guinea. Under the command of Frigate Captain Martin, unable to dive and with only one engine functioning and a jammed rudder, she limped across the English Channel and sought refuge in Plymouth.
On 3 July, the British, concerned that the German Kriegsmarine would take over the French Fleet at the French armistice, executed Operation Catapult. The Royal Navy blockaded the harbours where French warships were anchored, and delivered an ultimatum: rejoin the fight against Germany, be put out of reach of the Germans, or scuttle. Few accepted willingly; the North African fleet at Mers-el-Kebir and the ships based at Dakar (French West Africa) refused. The French battleships in North Africa were eventually attacked and all but one sunk at their moorings by the Mediterranean Fleet.
French ships lying at ports in Britain and Canada were also boarded by armed marines, sailors and soldiers, but the only serious incident took place at Plymouth aboard Surcouf on 3 July, when two Royal Navy submarine officers, Commander Denis 'Lofty' Sprague, captain of , and Lieutenant Patrick Griffiths of , and French warrant officer mechanic Yves Daniel were fatally wounded, and a British seaman, Albert Webb, was shot dead by the submarine's doctor.Reports of French Sailors Le Nistour (the ship's doctor) and French Officer Bouillaut on boarding incident and Bouillat's shooting of Sprague and Griffiths are available in file TTY/684 at the Service Historique de la Marine (Vincennes Archives, Paris)
Free French Naval Forces By August 1940, the British completed Surcoufs refit and turned her over to the Free French Naval Forces (Forces Navales Françaises Libres, FNFL) for convoy patrol. The only officer not repatriated from the original crew, Frigate Captain Georges Louis Blaison, became the new commanding officer. Because of Anglo-French tensions over the submarine, each side accused the other of spying for Vichy France; the British also claimed that Surcouf was attacking British ships. Later, a British officer and two sailors were put aboard for "liaison" purposes. One real drawback was that she required a crew of 110–130 men, which was equivalent to three crews of more conventional submarines. This led to the Royal Navy's reluctance to recommission her.
Surcouf then went to the Canadian base at Halifax, Nova Scotia and escorted trans-Atlantic convoys. In April 1941, she was damaged by a German plane at Devonport. On 28 July, Surcouf went to the Portsmouth Naval Shipyard at Kittery, Maine for a three-month refit. After leaving the shipyard, Surcouf went to New London, Connecticut, perhaps to receive additional training for her crew. Surcouf left New London on 27 November to return to Halifax.
Capture of St. Pierre and Miquelon
In December 1941, Surcouf carried the Free French Admiral Émile Muselier to Canada, putting into Quebec City. While the Admiral was in Ottawa, conferring with the Canadian government, Surcoufs captain was approached by The New York Times reporter Ira Wolfert and questioned about the rumours the submarine would liberate Saint-Pierre and Miquelon for Free France. Wolfert accompanied the submarine to Halifax, where, on 20 December, they joined Free French "Escorteurs" corvettes Mimosa, , and , and on 24 December, took control of the islands for Free France without resistance.
United States Secretary of State Cordell Hull had just concluded an agreement with the Vichy government guaranteeing the neutrality of French possessions in the Western hemisphere, and he threatened to resign unless President of the United States Franklin D. Roosevelt demanded a restoration of the status quo. Roosevelt did so, but when Charles de Gaulle refused, Roosevelt dropped the matter. Ira Wolfert's stories – very favourable to the Free French (and bearing no sign of kidnapping or other duress) – helped swing American popular opinion away from the Vichy government. The Axis Powers' declaration of war on the United States in December 1941 negated the agreement. Still, the United States did not sever diplomatic ties with the Vichy Government until November 1942.
Later operations In January 1942, the Free French leadership decided to send Surcouf to the Pacific theatre, after she had been re-supplied at the Royal Naval Dockyard in Bermuda. However, her movement south triggered rumours that Surcouf would liberate Martinique from the Vichy regime. In fact, Surcouf was bound for Sydney, Australia, via Tahiti. She departed Halifax on 2 February for Bermuda, which she left on 12 February, bound for the Panama Canal.
Fate
Surcouf vanished on the night of 18/19 February 1942, about north of Cristóbal, Panama, while en route for Tahiti, via the Panama Canal. An American report concluded the disappearance was due to an accidental collision with the American freighter . Steaming alone from Guantanamo Bay on what was a very dark night, the freighter reported hitting and running down a partially submerged object, which scraped along her side and keel. Her lookouts heard people in the water, but, thinking she had hit a U-boat, the freighter did not stop, although cries for help were heard in English. A signal was sent to Panama describing the incident.