User:UltimaGecko/Operation Hartmut

Operationsbefehl Hartmut (literally "Operation Order Hartmut") was the code word to begin German submarine operations during Operation Weserübung - Nazi Germany's invasion of Denmark and Norway. Occasionally these operations are termed Operation Hartmut. The orders involved submarine screening actions for the German invasion fleet and reconnaissance - particularly off Narvik and Trondheim. The orders also resulted in a number of attacks on Allied forces - particularly in or near the fjords of the Norwegian coast.

The operation's reconnaissance and screening objectives succeeded for the most part, however Hartmut is notable for the large number of faulty torpedoes fired and four u-boats sunk. These problems came at a time when the war in the Atlantic was still going exceptionally well against Britain. The deployment of u-boats during Operation Weserübung is occasionally criticized as a waste of manpower and materiel for this reason. The use of magnetic pistols and operations in cold weather rendered the G7e torpedo ineffective. Speculation persists that massive torpedo failure during this campaign provoked German naval high command into improving the weapon's performance. U-boat commanders like Prien and Schütze had the only patrols of their careers without any tonnage sunk.

Hartmut's Execution
First hints of an impending invasion of Norway and Denmark came in March 1940. By early April, most of the u-boats to be used for Operation Hartmut as part of Operation Weserübung were ready. BdU Karl Dönitz intermittently sent ships to recon areas of the Norwegian coast and to try to locate portions of the British fleet.

Due to submarines' generally slow surface speed compared to surface vessels, many of the u-boats specifically assigned to perform in Operation Weserübung departed before the main surface fleet left from the mouth of the Weser river on the morning of April 7th. Twenty u-boats went out on April 3rd, 4th and 5th.

Hartmut Preparations
Preparations in the German submarine forces (U-bootwaffe) began in early March. On March 4th, 1940 Karl Dönitz received orders from his superiors in Berlin:


 * 1) Further U-boat sailings are to be stopped.  U-boats which have already sailed are not to operate off the Norwegian coast.
 * 2) All Naval forces to be ready for operations as quickly as possible.  No special degree of readiness.

Dönitz mobilized any vessel that could dive. Only 12 larger Type VII and Type IX submarines capable of operating in the Atlantic Ocean were fit for the operation. One older ocean-going Type IA was also included. 12 smaller Type II u-boats were called up, despite that the Norwegian coast limited their operating time. The operation subsequently disrupted training exercises in the Baltic Sea as 6 outdated Type IIA training submarines were brought into the North Sea.

At this point, commanders and crews were simply ordered into the North Sea. A sealed envelope aboard each of the u-boats held their official orders. The envelope was to be opened upon receiving the radio code word "Hartmut" (hence the attributed name Operation Hartmut).

Dönitz predicted spectacular results for his submarines. In his memoirs he wrote, "Undoubtedly the enemy would react sharply to the landing of German troops in Norway. Their operations could be directed at our occupied ports or their own facilities - that is, strategically important sites for the English... The enemy was also bound to the narrow waterways of the fjords; their ships would have to pass near the u-boats. They could only go unseen in very turbulent weather. The deployment of multiple u-boats in staggered formation would likely yield more shooting opportunities."

By the beginning of April 1940, 31 u-boats were ready for operations between England and Norway. On April 6th, the codeword "Hartmut" was transmitted and German submarines began their designated operations.

Attacks on Allied Vessels
German submarines operating near the Norwegian coast made numerous attacks on British ships, although many proved unsuccessful due to faulty torpedoes.

U-4
Sank the British T-class submarine HMS Thistle.

U-13
Sank the British steam merchant Swainby off the Shetland islands with one torpedo on April 17th.

After docking in Bergen for a short time, U-13 then sank the the Danish vessel Lily that had been taken as a prize by the British after the German Occupation of Denmark. The first torpedo failed to arm, but the second broke the ship in half. A few days later U-13 damaged another British ship before returning to port. .

U-37
Sank 1 Swedish tanker, 1 Norwegian freighter and 1 British freighter equalling 18,715 tons of shipping between April 10th and 12th.

U-38
There were two naval battles of Narvik on 10 April 1940 and 13 April 1940. U-38 and U-65 were positioned at the entrance of the fjord. When the Royal Navy arrived, U-38 fired at HMS Valiant and at HMS Southampton missing both. In the second battle, U-38 fired at the HMS Effingham but the torpedoes detonated prematurely.

U-47
U-47 under Günther Prien encountered "a wall of ships" on April 15th. A British fleet of cruisers and transport ships were anchored near Narvik offloading troops and war materials. Prien targetted two cruisers and two transports with the 4 forward torpedoes but none detonated. An hour and a half later after a thorough inspection of the tubes and torpedoes, Prien tried again. Again, with a textbook surfaced attack from 750m away using 4 torpedoes U-47 had no success. 1 detonated underwater after hitting a rock, well off course.

After leaving Ofotfjord, U-47 spotted and attacked the HMS Warspite. One torpedo detonated ahead of the battleship, while another detonated far behind. U-47 spent the next hours submerged under persistent depth charge attack.

U-48
U-48 under Herbert Schultze made multiple attacks on a fleet of 3 cruisers on April 10th, but the torpedoes failed to arm or detonated prematurely. Later on April 14th, U-48 attacked the HMS Warspite but both torpedoes failed to detonate. Warspite's destroyer screen fired on the vessel and U-48 was depth charged, but escaped destruction.

U-51
The submarine attacked a destroyer, but the torpedoes detonated prematurely. On April 19th, commander Dietrich Knorr attacked the French cruiser Émile Bertin, but both torpedoes missed.

U-65
Hans-Gerrit von Stockhausen commanding U-65 attacked a group of British destroyers, but the torpedoes missed or failed to arm. The u-boat subsequently suffered moderate damage when the same destroyers depth charged her.

Operation Results
In general, submarine attacks in the Norwegian waters proved ineffective. Despite orders to cease using magnetic pistols in late 1939, Dönitz had authorized commanders to use either magnetic or impact pistols on their torpedoes during Operation Weserübung. Cold water in the North Sea and Norwegian fjords hampered the use of electric torpedoes used at the time, which required heating to reach suitable operating temperature. Nearly two-thirds of the magnetic pistols failed by either detonating too early or not arming.

Four submarines were lost - including three more modern type VIIB and IXB boats.

Submarine Order of Battle
Operation Hartmut engaged nearly every submarine in Germany's navy - most notably, both antiquated Type IA submarines and all 6 of Germany's IIA coastal submarines, which were operating as training boats in the Baltic. Boats which were initially unavailable for action at the beginning of the operation took part in ferrying supplies or patrolling later on.

When Hartmut was issued on April 6th, 1940 the German plan designated the U-bootwaffe into 8 groups (along with a further Group Seven, which was cancelled).

U-Boat Group One
Patrol Area: Narvik, Harstad, Westfjord, Vagsfjord
 * U-25 - one of only two Type IA submarines in the Kriegsmarine. Under the command of Viktor Schütze, U-25 had no success during Hartmut.
 * U-46 - a Type VIIB under Herbert Sohler with IWO Erich Topp. U-46 had no success during Hartmut.
 * U-51 - a Type VIIB under Dietrich Knorr, who failed to sink any vessels during Hartmut.
 * U-64 - a Type IXB under Georg-Wilhelm Schulz. U-64 was the first u-boat sunk by aircraft in the war. While anchored near Bjerkvik, British forces including a Fairey Swordfish launched from the HMS Warspite sank the boat on April 13th. Schulz and other surviving crew were rescued from the water by German troops in Norway.
 * U-65 - a Type IXB, which patrolled uneventfully in the North Sea for 36 days.

U-Boat Group Two
Patrol Area: Trondheim, Namsos, Romsdalsfjord
 * U-30 - a Type VIIA under Fritz-Julius Lemp, who was responsible for sinking the SS Athenia, the first ship sunk during the war. His patrol along the coast of Norway during Hartmut was uneventful.
 * U-34 - a Type VIIA, which torpedoed the scuttled Norwegian minelayer HNoMS Frøya on April 13th.

U-Boat Group Three
Patrol Area: Bergen, Aalesund, Shetland Islands
 * U-9 - a Type IIB commanded by Wolfgang Lüth. While U-9 had a relatively successful career, she sank no ships during Hartmut.
 * U-15 - a Type IIB successfully commanded by Herbert Wohlfarth, but which failed to sink any ships during Hartmut.
 * U-56 - a Type IIC with an uneventful patrol.
 * U-60 - a Type IIC with an uneventful patrol.
 * U-62 - a Type IIC with an uneventful patrol.

U-Boat Group Four
Patrol Area: Stavanger
 * U-1 - a Type IIA brought into frontline service. The submarine was sunk by mines, probably on April 6th.
 * U-4 - a Type IIA brought into frontline status before returning to her role as a training boat. Sank the British T-class submarine HMS Thistle.

U-Boat Group Five
Patrol Area: East of the Shetland Islands, Vagsfjord, Trondheim


 * U-37 - a Type IXA, one of the few boats to survive to be scuttled near the war's end. During Hartmut, Krvkpt Werner Hartmann sank 3 freighters.
 * U-38 - a Type IXA under Heinrich Liebe. U-38 engaged multiple ships, but was plagued with premature torpedo detonations and misses.
 * U-47 - a Type VIIB under Günther Prien and IWO Hans-Werner Kraus.
 * U-48 - a Type VIIB under Herbert Schultze and IWO Reinhard Suhren - both who ended the war as succesful U-Boat aces, but had no success on this patrol.
 * U-49 - a Type VIIB under Kurt von Gossler was sunk on April 15th by depth charges from the British destroyers HMS Fearless (H67) and HMS Brazen (H80) with one dead and 41 survivors.
 * U-50 - a Type VIIB was sunk by mines on April 6th en route to its patrol area.

U-Boat Group Six
Patrol Area: Pentland, Orkney islands, Shetland Islands
 * U-13 - a Type IIB commanded by Max-Martin Schulte. She sank 2 ships and damaged another during the operational time period. During this patrol, U-13 docked in recently occupied Bergen for a short time on April 19th to the 21st.
 * U-57 - a Type IIC under Claus Korth. U-57 sank a British tanker in late March, but had no success during Weserübung.
 * U-58 - a Type IIC under Herbert Kuppisch had one long patrol during the entire operation, but no ships sunk.
 * U-59 - a Type IIC commanded by Harald Jürst, which sank 1 Norwegian vessel on April 6th.

U-Boat Group Seven
Never assembled. Group Seven was designated to patrol the Eastern entrance to the English Channel, but was cancelled.

U-Boat Group Eight
Patrol Area: Lindesnes, Egernsund
 * U-2 - a Type IIA brought into frontline status for 2 patrols during the operation before returning to her role as a training boat.
 * U-3 - a Type IIA also brought into frontline service for the operation.
 * U-5 - a Type IIA brought into frontline service for one patrol.
 * U-6 - a Type IIA brought into frontline service for one patrol.

U-Boat Group Nine
Patrol Area: Bergen, Shetland Islands; SW of the Norwegian Coast.
 * U-7 - a Type IIB, which was on patrol west of the Norwegian Coast when Dönitz first received orders to prepare for Hartmut.. U-7 conducted 3 patrols during March/April of 1940.
 * U-10 - a Type IIB that sank a Norwegian vessel in February, but nothing on patrol during Hartmut.
 * U-19 - a Type IIB that sank 4 Danish merchants on March 19th and 20th.

Unassigned
These u-boats began patrols during the timeframe of Operation Weserübung, but were not fit for service (either due to damage, command change or other reasons) during the beginning of Hartmut. These subarines generally operated in the area of the Orkney islands, Shetland Islands, and near Bergen.
 * U-17 - a Type IIB for frontline training; until late April U-17 was not on war patrol.
 * U-23 - Otto Kretschmer's former Type IIB. The submarine had no success during Hartmut.
 * U-24 - a Type IIB that began operations in late April without success.
 * U-61 - a Type IIC under the command of Jürgen Oesten went on patrol in mid-April, but did not have any success.

Other Submarine Actions

 * U-26 - a Type IA - one of only two in the Kriegsmarine (the other being U-25 from Group One). U-26 delivered supplies to German troops in Trondheim, before going on patrol and sinking one British supply ship on April 21st.
 * U-29 - a Type VIIA also tasked with delivering supplies to Trondheim, but with an uneventful subsequent patrol.
 * U-32 - a Type VIIA that delivered supplies to Trondheim in early May.
 * U-43 - a Type IXA, which also delivered supplies to Trondheim. On her return journey she was bombed by two British Hudson aircraft on April 22nd, suffering light damage on the return journey to Wilhelmshaven.