Over the more than a century history of modern submarine warfare, submarines have repeatedly collided with each other and often entered into battle. Moreover, during all this time there was only one successful battle, when both boats were submerged.
A collision, unique for the submarine fleet, occurred at the end of World War II off the coast of Norway. On February 9, 1945, the British submarine Venturer torpedoed and sank the German submarine U-864 with a cargo of strategic raw materials and supplies for Japan.
Mercury and advanced technology for Japan
By the end of 1944, all sane people understood that the Axis countries were losing the war. True, in Berlin and Tokyo there were still a sufficient number of fanatical political and military leaders who did everything possible to gain as much time as possible, including in the struggle for their own lives.
At the end of World War II, Germany tried to help its Pacific ally to prolong Japan's participation in the war. As such, Berlin was ready to provide Tokyo with advanced technologies and scarce materials. So the Germans hoped to extend the resistance to Japan and win for themselves some extra months, in the hope of straightening out the plight at the fronts. Ultimately, Berlin fell under the blows of Soviet troops, and Japan held out in the war longer than its European ally.
In December 1944, an operation codenamed "Caesar" began in Germany. The purpose of the operation was to transfer advanced technologies and scarce raw materials to Japan. The only option to get to Japan was to use large German ocean-going submarines. At that time, there was not a single chance to break through to the shores of Japan on a surface ship.
In Operation Caesar, the German command used a large IXD2-class ocean-going submarine. The submarine was supposed to deliver blueprints and parts for modern German jet fighters to Japan. In particular, drawings and details of the Me-163 Komet rocket plane, the Me-262 fighter, German-made jet engines, as well as signed contracts for their licensed production in the Land of the Rising Sun.
In addition, on board the boat were drawings of submarines of the Caproni and Satsuki type, drawings of the radar company Siemens. Blueprints of the Italian Campini jet fighter. According to the American researcher of the submarine war in the Atlantic, Clay Blair, several German and Japanese designers were also on board the submarine as passengers.
The most dangerous cargo on board the German submarine was mercury. A total of 1,835 containers filled with mercury were loaded onto the boat. In total, there were about 65 tons of mercury on board. The rare metal was vital to the Japanese war industry.
Representation of opponents
A delicate and dangerous mission was entrusted to the large ocean-going IXD2 submarine numbered U-864.
The IXD2 type submarines were the culmination of the development of German ocean-going boats of the "ninth" series. It was a large surface submarine with a displacement of 1,616 tons and an underwater one of 2,150 tons. The greatest length of the boat was 87.6 meters, the width of the hull was 7.5 meters. The maximum immersion depth of the boat is 230 meters.
The navigation autonomy of the submarine at a speed of 12 knots was estimated at 23,700 nautical miles. The diesel-electric power plant of the submarine was represented by two diesel engines with a capacity of 2700 liters. with. each and two electric motors of 505 liters. with. The power plant provided the ship with a maximum surface speed of 19.2 knots, an underwater speed of 6.9 knots.
The IXD2 submarines had powerful weapons. The boat carried 24 torpedoes of 533 mm caliber, there were six launchers on board. The artillery armament of the U-864 was represented by one 105-mm gun 10.5 cm SK L / 45 with 150 rounds of ammunition, as well as one 37-mm and one 20-mm anti-aircraft machine guns.
The submarine U-864 was laid down on October 15, 1942 at the shipyard in Bremen. Launching took place on August 12, 1943, admission to the fleet took place on December 9, 1943. The boat was commanded by corvette captain Ralph-Reimar Wolfram.
From December to the end of October 1944, the U-864 submarine was part of the training flotilla. On November 1, 1944, she was transferred to the 33rd Kriegsmarine submarine flotilla. The submarines of this flotilla, in addition to combat patrols, were used as sea transports, transporting strategic raw materials and materials from Japan to Germany and from Germany to Japan.
The British learned about Operation Caesar thanks to German radio communications intercepted and decoded by intelligence. The British submarine HMS Venturer, which was of a much more modest size, was sent to intercept the enemy submarine with a valuable cargo on board.
The surface displacement of the British boat was only 662 tons, the underwater displacement was 742 tons. Maximum length - 62, 48 meters, maximum width of the hull - 4, 88 meters. The boat was driven by two diesel engines with a capacity of 400 liters. with. each and two electric motors of 450 liters. with. An important advantage of the British boat was the high underwater speed - 10 knots, the maximum surface speed was 11.25 knots. The maximum immersion depth is 109 meters.
The armament of the submarine, belonging to the widespread British series of U-type submarines, was also more modest than the German one. A total of four 533 mm torpedo tubes and ammunition of 8 torpedoes on board. Artillery armament was represented by a 76, 2-mm deck gun and three 7, 62-mm anti-aircraft machine guns.
The HMS Venturer (P68) was laid down under the military program on August 25, 1942, and launched on May 4, 1943. The boat was put into operation on August 19, 1943. The submarine was commanded by Lieutenant Jimmy Launders. The submarine actively participated in military campaigns since March 1944 and managed to sink several German and Norwegian merchant ships, as well as the German submarine U-771 on November 11, 1944.
But the most famous is rightly considered the 11th combat approach of HMS Venturer under the command of 25-year-old Lieutenant Launders. In turn, for the crew of the U-864 submarine, commanded by the 32-year-old corvette captain Ralph-Reimar Wolfram, the combat campaign in February 1945 was the first and last.
Successful underwater attack HMS Venturer
The Venturer submarine was sent to the area of Fedier Island on the basis of a German radiogram intercepted and decoded by British intelligence. The boat was ordered to find, intercept and sink the German submarine U-864 with a strategic cargo for Japan on board.
On February 6, 1945, a British submarine arrived at the designated area and began patrolling. By that time, Wolfram had already passed the given square, but luck was on the side of the British. On February 8, the British were able to verify the coordinates and course of the German submarine by intercepting a message from U-864, which reported to the base that it was returning back to Bregen due to a diesel engine malfunction.
Having shown caution, the Germans decided to return to the base and on February 9, 1945, they found their death.
The two boats met in the morning. At 8:40 am, the acoustician aboard the Venturer heard propellers. At the same time, Lieutenant Launders decided not to use sonar in order not to betray himself. At about 10 o'clock in the morning, British sailors with the help of a periscope discovered a German submarine. At this point, Wolfram himself raised the periscope, trying to find the German ships that were supposed to escort him to the base. By that time, the U-864 was running on only one diesel engine, using a snorkel.
After waiting for some time, Launders at 10:50 announced a military alert. By that time, he still had insufficient data to carry out a torpedo attack. The Venturer commander only knew the bearing to the target, but he also needed to get data on the course, speed and distance to the target. Venturer began to move on a parallel course to the right of the German submarine.
This persecution continued for a long time. Lieutenant Launders hoped the German submarine would surface, making it an easy target to attack. However, time passed and it became clear that the Germans were not planning to surface. At the same time, the U-864 was moving in a zigzag, most likely, on board it was already suspected of finding an enemy submarine nearby. Guided by the indirect information received, mainly by changing the bearing to the target, depending on the maneuvers of his own boat, Launders was gradually able to estimate the distance to the target, as well as the speed of the U-864 and the approximate size of the links of the broken line along which the Germans were walking.
The calculations Launders carried out with the help of available tools at hand. It is believed that the British officer used a tool of his own invention, which was a specialized version of a circular slide rule. After the end of World War II, both the instrument itself and the method of launching a torpedo attack along bearings will become standard practice.
From time to time, both boats continued to raise the periscope, which Launders used to refine the bearing to the target. It took the British officer about three hours to complete all the calculations and estimates. This time was enough for him to believe that he had studied the zigzag movement of the U-864 and its parameters well enough.
At 12:12 pm, the submarine Venturer fired a four-torpedo volley in a fan at the calculated point with the torpedo layout along the course and depth. Torpedo exit interval 17.5 seconds. On the German submarine, they heard the noise of going torpedoes and began an evasive maneuver into the depths.
The first three torpedoes missed their target, but the fourth provided a direct hit on the U-864 in the cockpit area.
At 12:14 pm, Lieutenant Launders recorded in the logbook that he heard a loud explosion, followed by the sounds of the destruction of the hull. And the acoustician of the British submarine reported that he no longer heard the noise of the propellers of the German boat. From the hit and explosion of a torpedo, the hull of the German submarine U-864 broke into two parts. The boat sank at a depth of approximately 150 meters.
Together with the boat, 73 people died - everyone on board the submarine.
For this successful attack, which was one of a kind with both submarines under water, Lieutenant Launders received a re-awarding bar for his Distinguished Service Order.
German submariners received a grave at a depth of 150 meters, two miles from the Norwegian island of Fedje.
And the Norwegians are a big environmental problem that they are still trying to cope with. There is still no consensus in Norway on whether to raise the boat and its dangerous cargo or to mothball all the remains found right at the bottom.
