SM UB-10 was a German Type UB I submarine or U-boat in the German Imperial Navy () during World War I.
UB-10 was ordered in October 1914 and was laid down at the AG Weser shipyard in Bremen in November. UB-10 was a little under in length and displaced between , 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-10 was broken into sections and shipped by rail to Antwerp for reassembly. She was launched in February 1915 and commissioned as SM UB-10 in March."SM" stands for "Seiner Majestät" () and combined with the U for Unterseeboot would be translated as His Majesty's Submarine. The U-boat was the first of her class to commence operations when she entered service on 27 March 1915.
UB-10 was the first boat assigned to the Flanders Flotilla, the unit in which she spent her entire career. Her first two commanders were Otto Steinbrinck and Reinhold Saltzwedel, fifth and eleventh, respectively, among the top-scoring German submarine commanders of the war. UB-10 was credited with sinking 37 ships, about two-thirds of them British fishing vessels. The first ship sunk, the neutral Dutch steamer , provoked outrage in the Netherlands and helped turn Dutch public opinion against Germany. That sinking was also the impetus behind a renewed effort to avoid attacking neutral ships by U-boats. In a 13-day span in July and August 1915, UB-10 sank 23 ships, and by herself accounted for nearly all of the tonnage sunk by the Flanders Flotilla in the latter month. She was also responsible for sinking the British destroyer in August 1916. UB-10 had two close calls with British submarines near the Schouwen Bank off Zeebrugge in 1916 and 1917, but survived both.
By 1918, UB-10 had been converted into a minelayer by the replacement of her torpedo tubes with four mine chutes. UB-10 was seriously damaged in a British air raid on Flanders in July 1918, and was decommissioned in September 1918 in a worn out condition. She was not deemed seaworthy to sail to Germany when the bases in Flanders were being evacuated by the Germans in October 1918 and was scuttled off Zeebrugge in early October.
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.Miller, pp. 46–47.Karau, p. 48. Project 34, a design effort begun in mid-August 1914, 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 long and displacing about with two torpedo tubes.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.
UB-10 was part of the initial allotment of seven submarines—numbered to —ordered on 15 October from AG Weser of Bremen, just shy of two months after planning for the class began.Williamson, p. 12. UB-10 was laid down by Weser in Bremen on 7 November. As built, UB-10 was long, abeam, and had a draft of . She had a single Körting 4-cylinder diesel engine for surface travel, and a single Siemens-Schuckert double-acting electric motor for underwater travel, both attached to a single propeller shaft. Her top speeds were , surfaced, and , submerged. At more moderate speeds, she could sail up to on the surface before refueling, and up to submerged before recharging her batteries. Like all boats of the class, UB-10 was rated to a diving depth of , and could completely submerge in 33 seconds.
UB-10 was armed with two torpedoes in two bow torpedo tubes. She was also outfitted for a single machine gun on deck. UB-10s standard complement consisted of one officer and thirteen enlisted men.Karau, p. 49.
After work on UB-10 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. In early 1915, the sections of UB-10 were shipped to Antwerp for assembly in what was typically a two- to three-week process. After UB-10 was assembled and launched on 20 February, she was loaded on a barge and taken through canals to Bruges where she underwent trials.
Early career The submarine was commissioned into the German Imperial Navy as SM UB-10 on 15 March 1915 under the command of Oberleutnant zur See (Oblt.z.S.) Otto Steinbrinck the 26-year-old former skipper of .Steinbrinck was in the Navy's April 1907 cadet class with 34 other future U-boat captains, including Werner Fürbringer, Heino von Heimburg, Hans Howaldt, and Ralph Wenninger. See: On 27 March, UB-10 became the first UB I boat to begin operations,Gibson and Prendergast, p. 38. and the first U-boat attached to the Flanders Flotilla () when it was organized on 29 March. When UB-10 began operations, Germany was in the midst of its first submarine offensive, begun in February. During this campaign, enemy vessels in the German-defined war zone (), 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.Tarrant, p. 14.
The UB I boats of the Flanders Flotilla were initially limited to patrols in the Hoofden, the southern portion of the North Sea between the United Kingdom and the Netherlands.Karau, p. 50. made the first sortie of the flotilla on 9 April, and UB-10 departed on her first patrol soon after. On 14 April, Steinbrinck and UB-10 sank their first ship, the 2,040-ton Dutch steamer , west of the North Hinder Lightship. Although no one was killed in the attack, the attack on a neutral ship sailing between neutral ports—Katwijk was sailing from Rotterdam to Baltimore—provoked outrage among the Dutch population.Abbenhuis, pp. 126–27. The sinking of Katwijk and other Dutch ships sharply turned public opinion in the Netherlands against Germany. As a direct result of UB-10s sinking of Katwijk, and to avoid further provoking the Dutch or other neutrals (primarily the United States), the German government issued an order on 18 April that no neutral vessels were to be attacked. The German government later paid compensation for the sinking of Katwijk.Halpern, p. 298
It was early June before UB-10 sank her next ship. The Belgian ship Menapier, carrying a load of iron ore from Algiers for Middlesbrough, was torpedoed and sunk off North Foreland by Steinbrinck on the 7th. Of the 23 persons on board the 1,886-ton ship, only 6 were saved. Menapiers master, his wife, and six-year-old daughter, the first mate, the pilot, and 12 other crewmen perished.
After UB-10s sister boat pioneered a route through British anti-submarine nets and mines in the Straits of Dover on 21 and 22 June, boats of the flotilla began to patrol into the English Channel.Karau, p. 51. , , and UB-10 soon followed with patrols in the Channel, but were hampered by fog and bad weather.Gibson and Prendergast, p. 50. Even though none of the boats sank any ships, by successfully completing their voyages, they helped further prove the feasibility of defeating the British countermeasures in the Straits of Dover.
On 30 June, Steinbrinck and the crew of UB-10, which was back patrolling in the North Sea, had a busy day when they sank eight British fishing vessels ranging from while patrolling between east of Lowestoft.Helgason, Guðmundur. , , , , , , , . U-Boat War in World War I. Uboat.net. Retrieved 31 March 2009. All eight of the sunken ships were smacks—sailing vessels traditionally rigged with red ochre sails—which were stopped, boarded by crewmen from UB-10, and sunk with explosives. The information on the website is extracted from
August 1915
UB-10 began August 1915 by capturing and burning Alert—another British fishing smack—off Lowestoft on the 1st. The same day, Fulgens, a 2,512-ton collier, was torpedoed one nautical mile (1.8 km) from Palling; the crew of the ship—UB-10s largest victim to-date—were all saved.
On 8 August, UB-10 captured and sank two more smacks—Arbor Vitae and Xmas Rose—off Lowestoft, and followed that up by sinking the largest ship of her career two days later. The Rosalie, headed from North Shields for San Francisco, was torpedoed from the Blankeney Buoy. A contemporary news account reported that Rosalie had been beached, but was apparently irreparably damaged; all her crew, however, was saved.
On 11 August, one day after sinking Rosalie, Steinbrinck and the crew of UB-10 bettered their 30 June activities by sinking ten fishing smacks off Cromer.Helgason, Guðmundur. , , , , , , , , , . U-Boat War in World War I. Uboat.net. Retrieved 31 March 2009. All ten ships, which ranged in size from 41 to 62 tons, were boarded and sunk by explosives. With these ten ships, the August tally for Steinbrinck and UB-10 was 7,309 tons, which accounted for nearly all of the 7,709 tons sunk by Flanders Flotilla boats that month.Tarrant, p. 148. In addition, counting the ships sunk at the end of July, UB-10 sank 23 ships in a 13-day span, nearly half the 55 ships sunk by the flotilla in both July and August.
End of the first submarine offensive On 18 August, the chief of the Admiralstab, Admiral Henning von Holtzendorff, issued orders suspending the first offensive. The suspension was in response to American demands after German submarines had sunk the Cunard Line steamer in May 1915, along with other high-profile sinkings in August and September. Holtzendorff's directive ordered all U-boats out of the English Channel and the South-Western Approaches and required that all submarine activity in the North Sea be conducted strictly along prize regulations.Tarrant, pp. 21–22. UB-10 did not sink another ship for the next four months.
On 20 December, UB-10 sank the last two ships under Steinbrinck's command. The 512-ton Belford and the 1,153-ton Huntly were both torpedoed off Boulogne; there were no casualties on Belford, but two men on Huntly died in the attack. The Huntly was the former German hospital ship Ophelia, which had been seized by English naval forces and renamed the previous year.
On 13 January 1916, Steinbrinck was succeeded by Oblt.z.S. Reinhold Saltzwedel in command of UB-10. Steinbrinck, who went on to command three more U-boats during the war—, , and —continued the successes he had in command of UB-10. He was fifth among the top-scoring German submarine commanders of the war, with a tally of 210,000 tons of shipping to his credit.Gibson and Prendergast, p. 378. Saltzwedel, Steinbrinck's 26-year-old replacement, was an eight-year veteran of the Kaiserliche Marine and a first-time U-boat commander.
Second submarine offensive By early 1916, the British blockade of Germany was beginning to have an effect on Germany and her imports. The Royal Navy had stopped and seized more cargo destined for Germany than the quantity of cargo sunk by German U-boats in the first submarine offensive.Tarrant, p. 25. As a result, the German Imperial Navy began a second offensive against merchant shipping on 29 February.Tarrant, p. 26. The final ground rules agreed upon by the German Admiralstab were that all enemy vessels in Germany's self-proclaimed war zone would be destroyed without warning, that enemy vessels outside the war zone would be destroyed only if armed, and—to avoid antagonizing the United States—that enemy passenger steamers were not to be attacked, regardless of whether in the war zone or not.