SM U-9
SM U-9 was a German Type U 9 U-boat. She was one of 329 submarines serving in the German Navy, and engaged in commerce raiding during World War I.
Construction
Her construction was ordered on 15 July 1908 and her keel was laid down by Kaiserliche Werft in Danzig. She was launched on 22 February 1910 and commissioned on 18 April 1910.Design
U-9 had an overall length of, her pressure hull was long. The boat's beam was, while the pressure hull measured. She had a draught of with a total height of. The boat displaced when surfaced and when submerged.U-9 was fitted with two Körting 8-cylinder plus two Körting 6-cylinder two-stroke petrol engines with a total of for use on the surface and two Siemens-Schuckert double-acting electric motors plus two 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. Originally, the boat was equipped with a machine gun, which was augmented with a Hotchkiss gun when war broke out in 1914. In 1915, an additional gun was fitted. When U-9 underwent a major refit in 1916, two mine-laying rails were added, which were later removed again. The boat's complement was 4 officers and 31 enlisted.
Service history
On 16 July 1914, the crew of U-9 reloaded the torpedo tubes while submerged, the first time a submarine had done so. On 1 August 1914, Kapitänleutnant Otto Weddigen took command. On 22 September, while patrolling the Broad Fourteens, a region of the southern North Sea, U-9 found a squadron of the British armoured cruisers,, and, that had been assigned to prevent German surface vessels from entering the eastern end of the English Channel. She fired four of her torpedoes, reloading while submerged and sank all three in less than an hour leading to the deaths of 1,459 British sailors.It was one of the most notable submarine actions of all time. Members of the Admiralty who had considered submarines mere toys, no longer expressed that opinion after this event. On 15 October, U-9 sank an cruiser. On 12 January 1915, Johannes Spieß relieved Weddigen, and commanded U-9 until 19 April 1916. During this period, she sank 13 ships totalling, consisting of ten small fishing vessels and the British steamers Don, Queen Wilhelmina and Serbino. After April 1916, she was withdrawn from front-line duties to be used for training. U-9 and the raider were the only ships which Kaiser Wilhelm II awarded the Iron Cross
Raiding history
| Date | Name | Flag | GRT/ Disp | Notes |
| 22 September 1914 |  United Kingdom|navalHMS|Cressy|1899|6 |