UB-12 was ordered in October 1914 and was laid down at the AG Weser shipyard in Bremen in November. UB-12 was a little under 28 metres (92ft) in length and displaced between 127 and 141 tonnes (125 and 139 long tons), depending on whether surfaced or submerged. She carried two torpedoes for her two bow torpedo tubes and was also armed with a deck-mounted machine gun. UB-12 was broken into sections and shipped by rail to Antwerp for reassembly. She was launched and commissioned as SM UB-12 in March 1915.[Note 1]
UB-12 spent her entire career in the Flanders Flotilla and sank 22 ships, about half of them British fishing vessels. The U-boat was also responsible for sinking the British destroyer HMSLaforey in 1917. By early 1917, UB-12 had been converted into a minelayer with the replacement of her torpedo tubes with four mine chutes. UB-12 disappeared after 19 August 1918.
Design and construction
After the German Army's rapid advance along the North Sea coast in the earliest stages of World War I, the German Imperial Navy found itself without suitable submarines that could be operated in the narrow and shallow seas off Flanders.[13][14] Project 34, a design effort begun in mid-August 1914,[14] produced the Type UB I design: a small submarine that could be shipped by rail to a port of operations and quickly assembled. Constrained by railroad size limitations, the UB I design called for a boat about 28 metres (92ft) long and displacing about 125t (123 long tons) with two torpedo tubes.[13][Note 2]
UB-12 was part of the initial allotment of seven submarines—numbered UB-9 to UB-15—ordered on 15 October from AG Weser of Bremen, just shy of two months after planning for the class began.[13][15]UB-12 was laid down by Weser in Bremen on 7 November.[1] As built, UB-12 was 27.88 metres (91ft 6in) long, 3.15 metres (10ft 4in)abeam, and had a draft of 3.03 metres (9ft 11in). She had a single 59-brake-horsepower (44kW)Körting 4-cylinder diesel engine for surface travel, and a single 119-shaft-horsepower (89kW)Siemens-Schuckertelectric motor for underwater travel, both attached to a single propeller shaft. Her top speeds were 7.45 knots (13.80km/h; 8.57mph), surfaced, and 6.24 knots (11.56km/h; 7.18mph), submerged.[2] At more moderate speeds, she could sail up to 1,500 nautical miles (2,800km; 1,700mi) on the surface before refueling, and up to 45 nautical miles (83km; 52mi) submerged before recharging her batteries. Like all boats of the class, UB-12 was rated to a diving depth of 50 metres (160ft), and could completely submerge in 33 seconds.
UB-12 was armed with two 45-centimeter (17.7in)torpedoes in two bow torpedo tubes. She was also outfitted for a single 8-millimeter (0.31in)machine gun on deck. UB-12's standard complement consisted of one officer and thirteen enlisted men.[16]
After work on UB-12 was complete at the Weser yard, she was readied for rail shipment. The process of shipping a UB I boat involved breaking the submarine down into what was essentially a knock down kit. Each boat was broken into approximately fifteen pieces and loaded onto eight railway flatcars.[16] In February 1915, the sections of UB-12 were shipped to Antwerp for assembly in what was typically a two- to three-week process. After UB-12 was assembled and launched on 2 March,[1] she was loaded on a barge and taken through canals to Bruges where she underwent trials.[16]
Early career
The submarine was commissioned into the German Imperial Navy as SM UB-12 on 29 March 1915 under the command of Kapitänleutnant (Kapt.) Hans Nieland,[1] a 29-year-old first-time U-boat commander.[17][Note 3] On 18 April, UB-12 joined the Flanders Flotilla (German: U-boote des Marinekorps U-Flotille Flandern),[1] which had been organized on 29 March.[16] When UB-12 joined the flotilla, Germany was in the midst of its first submarine offensive, begun in February. During this campaign, enemy vessels in the German-defined war zone (German: Kriegsgebiet), which encompassed all waters around the United Kingdom, were to be sunk. Vessels of neutral countries were not to be attacked unless they definitively could be identified as enemy vessels operating under a false flag.[18]
On 24 July, Nieland and UB-12 sank four British fishing vessels while patrolling between 30 nautical miles (56km; 35mi) east-northeast of Lowestoft.[19][20] All four of the sunken ships were smacks—sailing vessels traditionally rigged with red ochre sails[21]—which were stopped, boarded by crewmen from UB-12, and sunk with explosives.[22]UB-12 similarly sank a pair of smacks off Lowestoft on 4 August,[22][23] and another trio from 23 to 25 August.[22][24]
On 21 November, Nieland was succeeded by Oberleutnant zur See (Oblt.) Wilhelm Kiel in command of UB-12.[25] Under Kiel's command, UB-12 sank three ships on 21 February 1916: the 92 GRT Belgian fishing ship La Petite Henriette,[26] the largest sunk to-date by UB-12,[19] and another pair of British smacks, Oleander and W.E. Brown.[27]
UB-12 sank her largest ship, Silksworth Hall of 4,777gross register tons(GRT), on 10 April. The British-registered ship was en route from Hull to Philadelphia in ballast when Kiel torpedoed her without warning a little more than one nautical mile (two kilometers) from the Corton Lightvessel.[28] Other ships picked up 31 survivors from Silksworth Hall, but 3 men were lost.[28][29] Later in the month, Admiral Reinhardt Scheer, the newest commander-in-chief of the High Seas Fleet, called off the merchant shipping offensive and ordered all boats at sea to return, and all boats in port to remain there.[30]
Grand Fleet ambush attempts
In mid-May, Scheer completed plans to draw out part of the British Grand Fleet.[31] The German High Seas Fleet would sortie for a raid on Sunderland,[32] luring the British fleet across "'nests' of submarines and mine-fields".[31] In support of the operation, UB-12 and five other Flanders boats set out at midnight 30/31 May to form a line 18 nautical miles (33km; 21mi) east of Lowestoft.[32][Note 4] This group was to intercept and attack the British light forces from Harwich, should they sortie north to join the battle.[32] Unfortunately for the Germans, the British Admiralty had intelligence reports of the departure of the submarines which, coupled with an absence of attacks on shipping, aroused British suspicions.[31]
A delayed departure of the German High Seas Fleet for its sortie (which had been redirected to the Skagerrak) and the failure of several of the U-boats stationed to the north to receive the coded message warning of the British advance caused Scheer's anticipated ambush to be a "complete and disappointing failure".[32] In UB-12's group, only UB-10 sighted the Harwich forces, and they were too far away to mount an attack.[32] The failure of the submarine ambush to sink any British capital ships allowed the full Grand Fleet to engage the numerically inferior High Seas Fleet in the Battle of Jutland, which took place 31 May – 1 June.[33]
About half of UB-12's 22 victims were fishing smacks, traditionally outfitted with red ochre sails, like this contemporary smack.
Kapitänleutnant Georg Gerth took command of UB-12 on 26 June,[34]Oblt.Kiel was assigned to command the new minelaying submarine UC-18.[25] Two months later, Admiral Scheer set up another ambush for the British fleet with plans for another High Seas Fleet raid on Sunderland (as had been the original intention in May). The German fleet planned to depart late in the day on 18 August and shell military targets the next morning. As in May, UB-12 was part of a group intended to attack the Harwich forces. As one of five boats forming the second line of boats from the Flanders Flotilla,[Note 5]UB-12 was stationed off Texel by the morning of 20 August.[35] Once again, British intelligence had given warning of the impending attack and ambush, causing the Grand Fleet to sortie at 16:00 on 18 August, five hours before the German fleet sailed. Faulty intelligence caused Scheer initially to divert from Sunderland, and then to eventually call off the whole operation. Although U-boats to the north sank two British light cruisers,[Note 6]UB-12 and her group played no part in the action.[35]
In September, Gerth led UB-12 in sinking two more ships and capturing a third ship as a prize. The 313 GRT Norwegian steamer Rilda was sunk on 6 September,[36] while the 55 GRT Marjorie was sunk on the 28th.[37] In between the Dutch ship Niobe was seized as a prize on the 7th.[38]
Conversion to minelayer
UB-12 and three sister boats—UB-10, UB-16, and UB-17—were all converted to minelaying submarines. UB-12 was at the dockyard from November 1916 to January 1917,[39] and it is likely the boat was converted during this timeframe. The conversion involved removing the bow section containing the pair of torpedo tubes from each U-boat and replacing it with a new bow containing four mine chutes capable of carrying two mines each. In the process, the boats were lengthened to 105 feet (32m), and the displacement increased to 147t (145 long tons) on the surface, and 161t (158 long tons) below the surface.
During this same time, Kapt. Gerth was transferred to SMUC-61,[34] and replaced on UB-12 by Oblt. Friedrich Moecke in early November.[40] Moecke was, in turn, replaced by Oblt. Ernst Steindorff in January 1917.[41]
By March, the newly converted submarine had begun laying mines off the French coast. The French NavytrawlerElisabeth struck one of UB-12's mines off Calais on 13 March and sank.[42] Five days later, the British auxiliary minesweeperHMS Duchess of Montrose sank with a loss of 12 men after detonating a mine laid by UB-12 off Gravelines.[43] On 23 March, HMSLaforey, a destroyer with the Dover Patrol, struck one of UB-12's mines off Cape Gris-Nez and went down with the loss of 59 men.[44]
In May, UB-12 was on a patrol with UB-39 in the English Channel.[45] On the night of 14/15 May while UB-12 was on the surface,[46] Steindorff noted a large underwater explosion some miles away in a British minefield, and when UB-39 failed to return to Zeebrugge, one of the bases for the Flanders Flotilla, reported what was likely the demise of UB-39 at the hands of a British mine.[47]
April found two more victims added to UB-12's tally. On the 20th, Nepaulin, another British auxiliary minesweeper was lost on one of UB-12's mines near the Dyck Lightvessel.[48] Six days later, the British steamer Alhama was mined while loaded with pit props destined for Dunkirk.[49] The 1,744 GRT cargo ship was the largest ship sunk by UB-12 since the Silksworth Hall, sunk the previous April. UB-12 sank another two ships under Steindorff's command, one each in June and July.[19] The steamer Dulwich—carrying coal from Seaham for London—was mined and sunk with the loss of five men on 10 June.[50] One month later, the French patrol vessel Jupiter I was mined off Calais.[51] These were the last two ships credited to mines from UB-12 for the next fourteen months.[19]
Fate
UB-12's activities over the next year are not well documented, and no specific record of her can be found in English-language sources. However, it is known that during this period, she was helmed by four different commanders,[1] with the final officer, Oblt. Ernst Schöller, assuming command in May 1918.[52] Under Schöller's command, UB-12 departed Zeebrugge on 19 August to lay mines in the Downs off the Kentish coast, but never returned.[53] According to one British source, UB-12 was herself mined off Helgoland sometime in August.[54] Author Dwight Messimer considers this unlikely given that Helgoland is nowhere near the route that UB-12 could have taken to get to the Downs.[53] A postwar German study concluded the two most likely fates for UB-12 were that she either struck a British mine or was destroyed by one of her own mines that malfunctioned during deployment.[53] Messimer also considers it possible that UB-12 may have had a diving accident related to her conversion to a minelayer.[53]
Some two months after UB-12's presumed loss, she was credited with the sinking of her final ship.[19] On 27 October, two weeks before the end of the war, the 92 GRT British ship Calceolaria struck one of UB-12's mines near the Elbow Lightvessel and sank.[55]
↑ "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
↑ A further refinement of the design—replacing the torpedo tubes with mine chutes but changing little else—evolved into the Type UC I coastal minelaying submarine. See: Miller, p. 458.
SM UB-46 was a Type UB II submarine or U-boat for the German Imperial Navy during World War I. UB-46 operated in the Mediterranean and the Black Seas, and was sunk by a mine in December 1916.
SM U-28 or U-XXVIII was a U-27-class U-boat or submarine for the Austro-Hungarian Navy. U-28, built by the Austrian firm of Cantiere Navale Triestino (CNT) at the Pola Navy Yard, was launched in January 1917 and commissioned in June.
SM UB-47 was a Type UB II submarine or U-boat for the German Imperial Navy during World War I. UB-47 was sold to the Austro-Hungarian Navy during the war. In Austro-Hungarian service the B was dropped from her name and she was known as SM U-47 or U-XLVII as a member of the Austro-Hungarian U-43 class.
SM UB-43 was a Type UB II submarine or U-boat for the German Imperial Navy during World War I. UB-43 was sold to the Austro-Hungarian Navy during the war. In Austro-Hungarian service the B was dropped from her name and she was known as SM U-43 or U-XLIII as the lead boat of the Austro-Hungarian U-43 class.
SM UB-42 was a Type UB II submarine or U-boat for the German Imperial Navy during World War I. UB-42 operated in the Mediterranean and the Black Seas during the war. She was broken up at Malta in 1920.
SM UB-10 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I.
SM UB-13 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. The submarine was probably sunk by a British mine net in April 1916.
SM UB-16 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. The submarine was sunk by a British submarine in May 1918.
SM UB-17 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. The submarine disappeared during a patrol in March 1918.
SM UB-2 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. She sank eleven ships during her career and was broken up in Germany in 1920.
SM UB-6 was a German Type UB I submarine or U-boat in the German Imperial Navy during World War I. The submarine was interned after running aground in neutral Dutch waters, and was scuttled by her crew at Hellevoetsluis.
SM UB-30 was a German Type UB II submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 22 July 1915 and launched on 16 November 1915. She was commissioned into the German Imperial Navy on 18 March 1916 as SM UB-30.
SM UB-31 was a German Type UB II submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 22 July 1915 and launched on 16 November 1915. She was commissioned into the German Imperial Navy on 25 March 1916 as SM UB-31.
SM UB-36 was a German Type UB II submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 22 July 1915 and launched on 15 January 1916. She was commissioned into the German Imperial Navy on 22 May 1916 as SM UB-36.
His Majesty's or HM Armed Smack Inverlyon was a fishing smack that was converted to a Q-ship during the First World War. Q-ships served as decoys to lure German submarines near enough so that concealed weapons could be brought to bear and sink the submarines. On 15 August 1915, Inverlyon succeeded in luring German submarine UB-4 within range and sinking her with nine shots from her gun. The Royal Navy Gunner in command of the vessel, Ernest Martin Jehan, received the Distinguished Service Cross and members of Inverlyon's crew shared the bounty offered for German submarines. After Inverlyon's Q-ship career ended, she returned to fishing, but was sunk by U-55 on 1 February 1917.
SM U-60 was a German Type UB III submarine of the Imperial German Navy in the First World War. She took part in the First Battle of the Atlantic.
SM UB-50 was a German Type UB III submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 20 May 1916. She was commissioned into the Pola Flotilla of the German Imperial Navy on 12 July 1917 as SM UB-50.
SM UB-64 was a German Type UB III submarine or U-boat in the German Imperial Navy during World War I. She was commissioned into the German Imperial Navy on 5 August 1917 as SM UB-64.
SM UB-78 was a German Type UB III submarine or U-boat in the German Imperial Navy during World War I. She was commissioned into the German Imperial Navy on 20 October 1917 as SM UB-78. Mined off Dover on 19 April 1918 all 35 crew lost.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Hans Nieland". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 January 2015.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Wilhelm Kiel". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 January 2015.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Georg Gerth". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 January 2015.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Wilhelm Braun". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 January 2015.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Ernst Schöller". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 January 2015.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Hans Nieland". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
1 2 3 4 5 6 Helgason, Guðmundur. "Ships hit by UB 12". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. Helgason, Guðmundur. "Ships hit during WWI: Activity". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: Henry Charles". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: Kathleen". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: Prosper". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.. U-Boat War in World War I. Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. Helgason, Guðmundur. "Ships hit during WWI: Challenger". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: Heliotrope". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.. U-Boat War in World War I. Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. Helgason, Guðmundur. "Ships hit during WWI: Boy Bert". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: Integrity". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: Young Frank". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.. U-Boat War in World War I. Uboat.net. Retrieved 30 March 2009.
1 2 Helgason, Guðmundur. "WWI U-boat commanders: Wilhelm Kiel". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. Helgason, Guðmundur. "Ships hit during WWI: Oleander". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net., Helgason, Guðmundur. "Ships hit during WWI: W.e. Brown". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.. U-Boat War in World War I. Uboat.net. Retrieved 30 March 2009.
1 2 Helgason, Guðmundur. "WWI U-boat commanders: Georg Gerth". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Rilda". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Marjorie". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Niobe (p.)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Elisabeth". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Laforey (hms)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Nepaulin". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Alhama". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Dulwich". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Jupiter I". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "WWI U-boat commanders: Ernst Schöller". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
↑ Helgason, Guðmundur. "Ships hit during WWI: Calceolaria". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 30 March 2009.
Gardiner, Robert; Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN978-0-87021-907-8. OCLC12119866.
Gibson, R. H.; Maurice Prendergast (2003) [1931]. The German Submarine War, 1914–1918. Annapolis, Maryland: Naval Institute Press. ISBN9781591143147. OCLC52924732.
Grant, Robert M. (2003). U-boat Hunters: Code Breakers, Divers and the Defeat of the U-boats, 1914–1918. Annapolis, Maryland: Naval Institute Press. ISBN978-1-59114-889-0. OCLC54688427.
Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. Vol.2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN0-85177-593-4.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
German Empire 
