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Posted on Apr 27, 2012 in War College

The Rubis – Free French Submarine

By Stefen Styrsky

The Rubis, a minelayer submarine of the Free French Navy, found itself with a torpedo stuck in one tube, malfunctioning ballast tanks and leaking batteries, in the middle of a German minefield.

Servicemen in the French navy faced a difficult choice in June of 1940. Their nation was defeated. Part of the armistice agreement with Germany demanded the return of all naval units to the home country. Individual French commanders could obey and face possible integration into the Kriegsmarine, wait out the war in some far-flung tropical port—or continue the fight as a British auxiliary.

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The captain and crew of the Rubis, a Saphir-class submarine minelayer that had been docked at Dundee, Scotland, when France capitulated, made the latter choice. Infused with a love of the homeland, the sailors aboard Rubis immediately enlisted on the British side. Their enthusiasm for the struggle against Germany inspired them to acts of great daring. By war’s end the tiny Rubis would be the most successful unit of the entire Free French navy.

The Rubis began its career in April of 1933. A small submarine, only 70 meters long and with a surface displacement of 760 tons, it carried 42 crewmembers, five torpedo tubes (two external), and 32 mines. its guns were a standard complement of submarine armament: a 75mm deck gun, one 13.2mm machine gun and two 8mm machine guns. Twin diesel engines provided a maximum surface speed of 12 knots. Submerged, Rubis could briefly reach 9 knots on battery power.

In the late 1930s the Rubis was sort of a celebrity. During the summer she sailed between the resort towns of Brittany and Normandy, showing off for the tourists. Rubis became known as the submarine with the dog. its mascot, Bacchus, a black and white mutt, often sat on deck like some fanciful figurehead when the populace came out to greet the arriving boat. Doted on by the crew, Bacchus also went on every one of the sub’s wartime missions.

When war first broke out, the Rubis participated in the campaign to prevent German occupation of Norway. One operation during this time reportedly took the submarine up a fjord and claimed the honor of a 36-hour operational dive, the longest on record. With the invasion of France, the Allies were forced to cede Norway to the Germans. The Rubis remained in the Norway arena, operating out of Dundee, Scotland, where it was docked when Paris surrendered in May 1940.

In August of 1941 the Rubis was ordered to mine several shipping channels about two miles off the Norwegian coast. First Lieutenant Henri Rousselot had just been promoted to command after the Rubis’ previous captain, Georges Cabanier, accepted a new assignment that May. It was Rousselot’s second mission as captain and one that would make the boat and its crew the toast of the exile fleets.

Norway’s long coast allowed the Germans to more easily skirt the English blockade set up to prevent enemy warships from slipping into the Atlantic and threatening supply lines. The Nordic countries also possessed iron ore the German military desperately needed. Laying mines in the area interrupted the flow of raw materials.

Gazing through the periscope after the first dispersal, Rousselot sighted a lone tanker steaming in the opposite direction. He ordered the stern number 3 external tube fired. There was a whoosh, and the countdown. Seconds passed without an explosion.

Rousselot asked if the torpedo had been fired. The gunner insisted it had. Pressure gauges indicated the tube was open, but the periscope showed no wake of a running torpedo.

Then the crew noticed a hum sounding throughout the ship. The torpedo was running but somehow stuck in the tube. That meant it was armed and would explode on contact. As long as the Rubis didn’t strike anything with its stern the submarine was safe. Since there was nothing to be done about it, the men shrugged off the danger in a way that was a hallmark of the Rubis crew.

The lucky tanker soon disappeared over the horizon.

The Rubis then proceeded to the next assigned area. Immediately following the release of the final mine, four ships emerged from the channel headed right for the Rubis. Two were convoy escorts, and the other two were merchants flying the swastika.

Because it was daylight the Rubis was submerged and unseen by the convoy’s spotters. The crew hurriedly went to action stations again, and Rousselot fired both bow tubes. After a short interval a tremendous crash knocked out the submarine’s lights, and the Rubis angled steeply, threatening to surface uncontrolled.

Both torpedoes had found a target, but the explosion was so close it damaged the submarine. The shadow of the sinking ship, later identified as the Finnish merchantman Hogland, actually darkened the small window in the periscope room.

Rousselot ordered the crew to the bow to level the boat. He then took the Rubis down, resting it on the bottom to await the expected counterattack. A few distant explosions sounded but it was impossible to tell if they were depth charges or the convoy running against the mines. When silence reigned for several minutes the Rubis’ crew was disappointed. The attack was over. The men had hoped to brag about surviving depth charges, especially since their sister submarine Minerve survived 20 depth charges on an earlier patrol.

However, the Rubis had to stay on the bottom until any lurking hunters gave up and rescue ships left the area. For 18 hours the crew did nothing except sleep or talk in whispers. Near the end the men started to feel lethargic, a sign carbon dioxide was building to dangerous levels. Rubis had to surface.

Rousselot ordered the ballast tanks blown. The Rubis scraped along the bottom, then settled again. A second set of ballast tanks produced the same result; normally, one set got the sub to surface. The explosion had damaged the tanks. They were leaking and slowly filling with water. Rousselot ordered all ballast tanks blown at once. The last-ditch attempt worked, and Rubis surfaced in darkness just after 9:00 p.m.

Unable to dive, the sub had to escape to friendly water as quickly as possible. This meant traversing an area marked on the sea charts as a massive German minefield protecting the Norwegian coast. Rousselot assured the British liaison officer on board the danger was minimal because the size of the field meant the mines must be thinly spread, and unlikely to threaten a narrow submarine.

Just as the Rubis slipped out of sight of land its engines died, setting it adrift in the minefield.

The batteries had started leaking acid and shorted out. Even worse, the acid combined with water in the bilge tanks and filled the interior with chlorine fumes, forcing the crew to take refuge on deck.

The Rubis was completely helpless and exposed to attack.

A distress call to the Admiralty brought even worse news. British ships would not meet the Rubis unless she cleared the mined areas. If she could not make it home Catalina flying boats would be sent for the crew, and the submarine would be scuttled.

When the order was read aloud, the crew laughed. “He’s determined to sink us, the Old Man,” Rousselot declared. The Old Man referred to Max Horton, the flag officer in charge of submarines. On an earlier patrol in the Bay of Biscay, the Rubis’ rudder had jammed, and she ran in circles for two days. Horton sent a British sub to collect the crew and torpedo the malfunctioning Rubis. Just in the nick of time, an engineer fixed the rudder and Rubis returned to Dundee.

Only when on deck did the crew, stranded in the minefield, realize how close they had been to the ship they torpedoed. Bits of metal from their own torpedoes were lodged into the outer wooden deck built over the steel hull.

Again luck saved the Rubis. The Catalinas were spotted, but they missed the submarine. Instead of an aerial rescue, engineers in gas masks got a few of the batteries online and the engines sputtered to life. Slowly, the submarine made it to open water. An escort of a cruiser, four destroyers and two tugs met her soon afterward. Refusing a tow, the Rubis chugged back to Dundee under her own power. The chlorine fumes kept the crew outside during the entire return trip.

The Free French admiralty was so happy with the Rubis’ performance a new decoration was created, the Croix de la Liberation just for her return. Admiral Muselier, the leader of the Free French Navy personally made the trip up from London to award the boat and crew the medal.

While no other mission would be as harrowing, the Rubis became a notable success among the exile navies fighting alongside the British. Her most fruitful month was in December 1944 when a German merchant, two submarine chasers and a minelayer all sank after striking mines laid by Rubis.

In all, the French submarine laid more than 680 mines over 23 operations. Most were off the Norwegian coast, but others sent her into the Bay of Biscay. She was even part of the task force dispatched to hunt and sink the German battleship Tirpitz. In total, her mines sank 21,000 GRT (gross register tons) of shipping, more than the rest of the Free French Navy combined. This included 22 enemy ships, 12 of which were German warships.

The Rubis was retired in 1946 and was sunk off the coast of France in 1958 for use as a sonar target. Divers can still visit her remains.

Click here to read about OPERATION CATAPULT, Winston Churchill’s controversial plan to keep French warships out of German hands that resulted in 1,300 French casualties at Mers-el-Kebir.

About the Author: 
Stefen Styrsky is a freelance writer living in Washington, D.C. He has published other military history articles in World at War magazine.



  1. OPERATION CATAPULT – Churchill’s Controversial Plan to Deny the Germans French Ships » Armchair General - [...] here to read about the exploits of the Rubis, a Free French submarine that joined the British to fight …

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