SM U-41 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-41 engaged in naval warfare and took part in the First Battle of the Atlantic.
Type U 31 submarines were double-hulled, ocean-going submarines similar to Type 23 and Type 27 subs in dimensions and differed only slightly in propulsion and speed. They were considered very good high sea boats with average manoeuvrability and good surface steering.
U-41 had an overall length of , her pressure hull was long. The boat's beam was (o/a), while the pressure hull measured . Type 31s had a draught of with a total height of . The boats displaced a total of ; when surfaced and when submerged.
U-41 was fitted with two Germania 6-cylinder two-stroke diesel engines with a total of for use on the surface and two Siemens-Schuckert double-acting electric motors with a total of for underwater use. These engines powered two shafts each with a propeller, which gave the boat a top surface speed of , and when submerged. Cruising range was at on the surface, and at under water. Diving depth was .
The U-boat was armed with four torpedo tubes, two fitted in the bow and two in the stern, and carried 6 torpedoes. Additionally U-41 was equipped in 1915 with one Uk L/30 deck gun. The boat's complement was 4 officers and 31 enlisted.
After the British heard of the sinking of the Anglo-Columbian on 23 December, , a British Q-ship in the guise of the American-flagged merchantman Baralong set out from Falmouth to present itself as a target.
U-41 stopped the merchantman Urbino on 24 December about 70 miles from Bishop Rock. U-41 sent a boarding party aboard to inspect the cargo. After finding war material on board, the Germans put the merchant crew off the ship in the lifeboats. U-41 was in the process of sinking Urbino with gunfire when, "Baralong", arrived on the scene at around 9:45, flying an American flag. Baralong turned away so that U-41 would be forced to use her diesel engines to catch up, and in doing so be fully surfaced. U-41 signalled Baralong to send their papers across in a ships boat. The crew of Baralong went through the motions of preparing a boat, while at same time readying for combat, and in doing so closed the distance to 700 yards and turned so her hidden guns were able to bear. Wyandra then fired its guns accompanied by rifle fire from Marines onboard. U-41 got off one shell in return before the crew abandoned the deck gun. One of Wyandras shots hit the submarine's conning tower killing the commander Kapitänleutnant Hansen and six others. After other hits, U-41 listed then dived but then rose again before sinking - only Oberleutnant zur See Iwan Crompton (badly wounded) and the helmsman escaping to be picked up along with the 42 from the Urbino by Wyandra. After Crompton returned to Germany in 1917, he claimed Wyandra had run down the lifeboat he was in.
It was also claimed that the Wyandra had not struck the American flag before firing which was a violation of the rules of war; while the use of a False Flag was allowed, it was required that a belligerent identify itself before initiating hostilities.
The event generated widespread outrage in Germany, especially among Kriegsmarine officers. The sinking was also commemorated in a propaganda medal designed by the German medallist Karl Goetz.