Operation Caesar

Operation Caesar
	Part of The Second World War
	; Location of U-864
Date	5 December 1944 – 9 February 1945
Location	North Sea 60°46′10″N4°37′15″E / 60.76944°N 4.62083°E
Result	British victory
Belligerents
Germany	United Kingdom
Commanders and leaders
Ralf-Reimar Wolfram †	Jimmy Launders
Strength
U-864 (Type IX U-boat)	HMS Venturer (V-class submarine)
Casualties and losses
U-864 sunk; 73 crew and passengers killed	None

Last updated October 28, 2023

Operation Caesar (Unternehmen Kaiser) was a secret mission carried out by Germany in the Second World War to supply Japan with advanced technology. The operation failed due to the sinking of U-864 by a British submarine, the only known example of a submerged submarine sinking another submerged submarine.^[1]

The operation

On 5 December 1944, U-864, on her maiden voyage, was dispatched on a secret mission to deliver supplies to Japan. U-864's primary cargo was advanced Messerschmitt jet engine parts for use in Japanese aircraft and V-2 missile guidance systems.^[1]^[2] Her secondary cargo comprised 64 long tons (65 t) of the strategic material mercury in 1,857 canisters for use in weapons production.^[1]

She left Kiel and headed north. While going through the Kiel Canal, U-864 grounded and damaged her hull. Her captain, Ralf-Reimar Wolfram, decided to sail to the U-boat pens at Bergen, Norway. On 12 January 1945, while U-864 was still undergoing repairs, British bombers attacked the pens, delaying the repairs further. The repairs were completed in early February and Wolfram embarked on his mission once again. British code breakers at Bletchley Park deciphered Enigma encoded transmissions and were alerted to U-864's mission. To counter the German U-boat, the Admiralty diverted the submarine HMS Venturer (Lieutenant James Launders), which had just left Lerwick in Scotland, to Fedje Island, off the coast of Norway to search for U-864.^[1]

Action of 9 February 1945

On 6 February 1945, U-864 experienced trouble with one of her engines, which began misfiring, greatly increasing the sounds the U-boat made. Wolfram contacted Bergen, informing them that he would be returning for further repairs. Wolfram was told that an escort would be waiting for them at Hellisøy on 10 February. At the same time, Venturer arrived off Fedje Island and began searching for the U-boat. On 9 February, Venturer's hydrophone operator detected a noise that sounded like a diesel engine. Launders raised periscope and surveyed the horizon, he spotted what he believed to be another periscope (in fact now thought to be the U-boat's snorkel) and began stalking it, assuming that it was U-864.^[1]

As Venturer followed the German U-boat, it became apparent that they knew they had been spotted due to the erratic, zigzag course U-864 began to take. After following the German submarine for three more hours, Venturer's crew made a calculated decision based on U-864's movements. At intervals of 17.4 seconds, Venturer fired all four of her torpedoes. Hearing the incoming torpedoes, U-864 took evasive manoeuvres, avoiding the first three torpedoes but unknowingly steered into the path of the fourth. The torpedo struck the U-boat, splitting her in half and sending her to the ocean floor. All 73 of her crew and passengers perished.^[1]

Aftermath

Analysis

The operation was a failure for the Germans. Had it not been for the damage the U-boat sustained or the British bombing of Bergen, U-864 would have had a month's lead on Venturer by the time the Enigma code was broken and she was dispatched, which would have made a significant difference to the outcome.

Casualties

The Germans lost U-864 and all 73 of her crew, including her captain, Ralf-Reimar Wolfram. The British suffered no casualties or damage. For his actions at Fedje, Lieutenant Launders received the Distinguished Service Order.^[1]

Subsequent events

After coming across documents listing mercury as one of the cargoes on board U-864, the Royal Norwegian Navy began searching for the wreckage. After searching for five years, the U-boat was found in October 2003 by the mine control vessel HNoMS Tyr, 4 km (2.2 nmi; 2.5 mi) off Fedje. After examining the site for two years, it became apparent that the mercury was indeed leaking into the ocean at increasing rates every year. Due to the hazards of mercury, fishing is now prohibited in the region. One study recommended entombing the wreck under a layer of sand, gravel and concrete. The Norwegian government instead awarded a contract to a salvage company to raise the wreck but the proposed operation was postponed pending additional studies.

The Norwegian government spent 15 years assessing possible risks of raising the wreck, with its dangerous unexploded torpedoes inside. Finally, in February 2017, it was decided to cover the U-864 with 50 centimetres of sand and 160,000 long tons (160,000 t) of rock to seal the mercury inside the wreck.^[3]

Related Research Articles

<span class="mw-page-title-main">Fedje</span> Municipality in Vestland, Norway

Fedje is an island municipality in the Nordhordland region of Vestland county, Norway. The administrative centre of the municipality is the village of Fedje. The traditional economic activity of the inhabitants is fishing.

German submarine U-219 was a Type XB submarine of Nazi Germany's Kriegsmarine during World War II. The U-boat was laid down on 31 May 1941 at the Germaniawerft yard at Kiel as yard number 625, launched on 6 October 1942, and commissioned on 12 December 1942 under the command of Korvettenkapitän Walter Burghagen.

German submarine U-864 was a Type IXD2 U-boat of Nazi Germany's Kriegsmarine in World War II. On 9 February 1945, she became the only submarine in history to be sunk by an enemy submarine while both were submerged. U-864 was sunk by the British submarine HMS Venturer, and all 73 men on board died.

SM U-151 or SM Unterseeboot 151 was a World War I U-boat of the Imperial German Navy, constructed by Reiherstieg Schiffswerfte & Maschinenfabrik at Hamburg and launched on 4 April 1917. From 1917 until the Armistice in November 1918 she was part of the U-Kreuzer Flotilla, and was responsible for 34 ships sunk (88,395 GRT) and 7 ships damaged.

German submarine U-269 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The U-boat was laid down on 18 September 1941 by Bremer Vulkan at Bremen-Vegesack, launched on 24 June 1942 and commissioned on 19 August under the command of Oberleutnant zur See Karl-Heinrich Harlfinger.

HMS Venturer was a Second World War British submarine of the V class that sank two German U-boats and five merchant ships during the war. Following the war, the boat was sold to Norway and was renamed HNoMS Utstein. She was discarded in 1964.

HMS Sea Nymph was a S-class submarine of the third batch built for the Royal Navy during World War II. Completed in July 1942, she spent the majority of her career patrolling the waters off Norway in the North Sea, then was sent to the Pacific but was forced back due to technical problems.

HMS Thistle (N24) was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched in October 1938. She was sunk by the German submarine U-4 on 10 April 1940 near Skudenes, Norway.

Captain James Stuart Launders, (1919–1988), was an officer in the Royal Navy during and after the Second World War. He retired from the service in 1974, but continued to serve in an unofficial capacity on training programs until his death in 1988. In addition to his reputation amongst his crew, colleagues, and historians as a brilliant, highly skilled, and courageous officer, Launders is remembered as the only submarine commander in history to have engaged and sunk an enemy submarine (U-864) using only his own unaided vessel (HMS Venturer) while both boats were fully submerged.

German submarine U-246 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 30 November 1942 at the Friedrich Krupp Germaniawerft yard at Kiel, launched on 7 December 1943 and commissioned on 11 January 1944 under the command of Kapitänleutnant Ernst Raabe.

<span class="mw-page-title-main">Ralf-Reimar Wolfram</span> German naval officer (1912–1945)

Ralf-Reimar Wolfram was a Korvettenkapitän during World War II. During his career he commanded two U-boats for a total of 118 days at sea spanning four patrols. During his third patrol he sank the SS Robert Gray, an American liberty ship. Robert Gray was a straggler from convoy HX 234 en route to Britain.

SM U-53 was one of the six Type U 51 U-boats of the Imperial German Navy during the First World War.

German submarine U-137 was a Type IID U-boat of Nazi Germany's Kriegsmarine in World War II. Her keel was laid down on 16 November 1939 by Deutsche Werke in Kiel. She was launched on 18 May 1940 and commissioned on 15 June 1940 with Oberleutnant zur See Herbert Wohlfarth in command.

SM U-16 or U-XVI was a U-10-class submarine or U-boat of the Austro-Hungarian Navy during World War I. U-16 was constructed in Germany and shipped by rail to Pola where she was assembled and completed in September 1915. She was commissioned in October 1915.

German submarine U-486 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down at the Deutsche Werke in Kiel as yard number 321, launched on 12 February 1944 and commissioned on 22 March with Oberleutnant zur See Gerhard Meyer in command.

German submarine U-771 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. She was ordered on 21 November 1940, and was laid down on 21 August 1942 at Kriegsmarinewerft, Wilhelmshaven, as yard number 154. She was launched on 26 September 1943 and commissioned under the command of Oberleutnant zur See Helmut Block on 18 November of that year.

The German U-boat U-864 was attacked and sunk on 9 February 1945 by HMS Venturer, a V-class submarine of the Royal Navy. Venturer was patrolling the waters around Fedje Island, off the Norwegian coast in the North Sea. The sinking remains the only incident in the history of naval warfare where one submarine sank another while both were submerged.

German submarine U-991 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

German submarine U-1053 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

The Yanagi missions, or more formally the Submarine Missions to Germany, were a series of submarine voyages undertaken by the Imperial Japanese Navy (IJN) during the Second World War, to exchange technology, skills and materials with Japan's Axis partners, principally Nazi Germany. These voyages had to run the gauntlet of the Western Allies naval superiority in the Indian and Atlantic Oceans; of the five westbound voyages, three arrived safely, with two submarines sunk en route, while of the three successful vessels only one completed her return voyage, with two sunk before reaching home.

References

1 2 3 4 5 6 7 Fletcher, Martin (19 December 2006). "Toxic timebomb surfaces 60 years after U-boat lost duel to the death". The Times. London. Archived from the original on 4 June 2011. Retrieved 7 November 2008.
↑ "World War II: HMS Venturer Sinks U-864". about.com. Retrieved 19 May 2008.
↑ Roblin, Sebastien (21 November 2017). "Aboard His Submarine, Jimmy Launders Sank Ralf-Reimar Wolfram's U-boat". War Is Boring. Retrieved 21 November 2017.