SM UB-3 - Design and Construction

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 environment off Flanders. 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 92 feet (28 m) long and displacing about 125 metric tons (138 short tons) with two torpedo tubes. UB-3 was part of the initial allotment of eight submarines—numbered UB-1 to UB-8—ordered on 15 October from Germaniawerft of Kiel, just shy of two months after planning for the class began.

UB-3 was laid down by Germaniawerft on 3 November and was launched on 5 March 1915. As built, UB-3 was 92 feet 2 inches (28.09 m) long, 10 feet 6 inches (3.20 m) abeam, and had a draft of 9 feet 10 inches (3.00 m). She had a single 60-brake-horsepower (45 kW) Daimler 4-cylinder diesel engine for surface travel, and a single 120-shaft-horsepower (89 kW) Siemens-Schuckert electric motor for underwater travel, both attached to a single propeller shaft. Her top speeds were 6.47 knots (11.98 km/h), surfaced, and 5.51 knots (10.20 km/h), submerged. At more moderate speeds, she could sail up to 1,650 nautical miles (3,060 km) on the surface before refueling, and up to 45 nautical miles (83 km) submerged before recharging her batteries. Like all boats of the class, UB-3 was rated to a diving depth of 50 metres (160 ft), and could completely submerge in 33 seconds.

UB-3 was armed with two 45-centimeter (17.7 in) torpedoes in two bow torpedo tubes. She was also outfitted for a single 8-millimeter (0.31 in) machine gun on deck. UB-3's complement consisted of one officer and thirteen enlisted men.