SM UB-10 - Early Career

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.) Otto Steinbrinck the 26-year-old former skipper of U-6. On 27 March, UB-10 became the first UB I boat to begin operations, and the first U-boat attached to the Flanders Flotilla (German: U-boote des Marinekorps U-Flotille Flandern) 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 (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.

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. UB-4 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 Katwijk, 6 nautical miles (11 km) 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. The sinking of Katwijk and other Dutch ships sharply turned public opinion in the Netherlands against Germany. As a direct result of UB-10's 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.

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. Menapier's master, his wife, and six-year-old daughter; the first mate; the pilot; and 12 other crewmen perished in the attack.

After UB-10's sister boat UB-6 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. UB-2, UB-5, and UB-10 soon followed with patrols in the Channel, but were hampered by fog and bad weather. 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 43 to 63 gross register tons (GRT) while patrolling between 20 and 35 nautical miles (37 and 65 km) east of Lowestoft. 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.