Type UB II submarine

The UB II type submarine was a class of U-boat built during World War I by the German Imperial Navy. They were enlarged from the preceding type UB I and were more effective vessels. The boats were a single hull design with a 50-metre maximum diving depth and a 30-45 second diving time. In 1915 and 1916, 30 were built at two different shipyards.^[2]

SM UB-45
Class overview
Builders	AG Weser, Bremen Blohm & Voss, Hamburg
Operators	Imperial German Navy  French Navy
Preceded by	UB I
Succeeded by	UB III
Built	1915–1916
In commission	1915–1931
Completed	30
Active	0
Lost	20[1]
Preserved	1 (UB-46 was salvaged)
General characteristics
Displacement	263–279 t (259–275 long tons) surfaced 292–305 t (287–300 long tons) submerged
Length	36.13–36.90 m (118 ft 6 in – 121 ft 1 in) (o/a)
Beam	4.36 m (14 ft 4 in)
Draught	3.66–3.75 m (12 ft 0 in – 12 ft 4 in)
Installed power	Körting, Daimler or Benz diesel engines, 270–284 PS (199–209 kW; 266–280 bhp) Siemens-Schuckert electric motor, 280 PS (206 kW; 276 shp)
Propulsion	1 shaft, 1 1.15 m (3 ft 9 in) propeller
Speed	8.82–9.15 knots (16.33–16.95 km/h; 10.15–10.53 mph) surfaced 5.71–6.22 knots (10.57–11.52 km/h; 6.57–7.16 mph) submerged
Range	6,450–7,200 nmi (11,950–13,330 km; 7,420–8,290 mi) at 5 knots (9.3 km/h; 5.8 mph) surfaced 45 nmi (83 km; 52 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	50 m (160 ft)
Complement	2 officers, 21 men
Armament	2 × 50 cm (19.69 in) bow torpedo tubes 2 external stern tubes fitted in some boats 1 × 5 cm (1.97 in) or 8.8 cm (3.46 in) deck gun

Design

The design of type UB II addressed many of the problems apparent in the preceding type UB I class. The UB II boats featured a two-shaft drive with a much larger battery capacity and larger engines. Storage batteries were placed forward of the central diving tanks to compensate for the much heavier engine installation.^[3]

The armament of the type UB II consisted of 50 cm G torpedoes launched from two bow tubes. The torpedo tubes were installed one above the other to allow for a bow design that would create optimal surface efficiency. A 5 cm gun was provided on the deck for surface use.^[3]

The weight of the boat was increased to 270 tons of surface displacement to accommodate these improvements. Saddle tanks were fitted to the sides of the pressure hull to allow greater fuel storage area.^[3]

List of Type UB II submarines

There were 30 Type UB II submarines commissioned into the German Imperial Navy.

name	launched[4]	commissioned[4]	merchant ships sunk (nbr/GRT)[4]	Fate
UB-18	21 Augustus 1915	11 December 1915	126 / 128.555	Rammed and sunk by trawler Ben Lawer December 1917
UB-19	2 September 1915	17 December 1915	14 / 11.558	Sunk by Q-ship HMS Penshurst November 1916
UB-20	20 September 1915	10 February 1916	13 / 9.914	Struck a mine and sank during diving trial July 1917
UB-21	20 September 1915	20 February 1916	32 / 35.188	Foundered on way to breakers 1920
UB-22	9 October 1915	2 March 1916	27 / 16.646	Struck a mine January 1918
UB-23	9 October 1915	12 March 1916	51 / 34.322	Interned at Corunna, Spain July 1917; broken up 1921
UB-24	18 October 1915	18 November 1915	none	Surrendered to France November 1918; broken up 1921
UB-25	22 November 1915	11 December 1915	none	Sunk after collision with SMS V26 March 1917. Salvaged, surrendered to the Allies November 1918; broken up 1919
UB-26	14 December 1915	7 January 1916	none	Sunk and raised by French Navy repaired as Roland Morillot BU 1931
UB-27	10 February 1916	23 February 1916	12 / 16.666	Sunk by HMS Halcyon July 1917
UB-28	20 December 1915	27 December 1915	none	Surrendered to Britain November 1918; broken up 1919-1920
UB-29	31 December 1915	18 January 1916	32 / 39.378	Previously thought being sunk by HMS Landrail, but likely mined December 1916 (wreck discovered in 2017, which contradicts the credit to Landrail. Landrail probably mistook UB-29 for another submarine, possibly the UC-19.
UB-30	16 November 1915	18 March 1916	18 / 19.606	Depth charged by HMS Landrail August 1918
UB-31	16 Novembr 1915	25 March 1916	27 / 72.370	Struck a mine May 1918
UB-32	4 December 1915	11 April 1916	22 / 42.889	Possibly sunk by aircraft September 1917, but was more likely sunk by a mine
UB-33	4 December 1915	22 April 1916	13 / 5.356	Sunk by mines April 1918
UB-34	28 December 1915	10 June 1916	31 / 39.219	Surrendered November 1918; broken up 1922
UB-35	28 December 1915	22 June 1916	42 / 47.862	Sunk by British warships including HMS Leven January 1918
UB-36	15 January 1916	22 May 1926	11 / 6.252	Sunk by mines May 1917
UB-37	28 December 1915	17 May 1916	30 / 20.500	Sunk by Q-ship Penshurst January 1917
UB-38	1 April 1916	19 July 1916	43 / 45.210	Struck a mine February 1918
UB-39	29 December 1915	29 April 1916	93 / 89.810	Struck a mine May 1917
UB-40	25 April 1916	17 August 1916	99 / 131.680	Scuttled October 1918
UB-41	6 May 1916	25 August 1916	8 / 8.387	Possibly struck a mine October 1917
UB-42	4 March 1916	23 March 1916	10 / 13.184	Surrendered November 1918; broken up in 1920
UB-43	8 April 1916	24 April 1916	22 / 99.202	Sold to Austria-Hungary July 1917; turned over to France as war reparation in 1920 and broken up
UB-44	20 April 1916	11 May 1916	1 / 3.409	Missing after 8 August 1916; possibly sunk by a torpedo boat
UB-45	12 May 1916	26 May 1916	3 / 11.666	Struck a mine November 1916
UB-46	31 May 1916	12 June 1916	4 / 8.099	Struck a Russian mine December 1916. Wreck raised in 1993 and put on display in Çanakkale Turkey.
UB-47	17 June 1916	4 July 1916	20 / 75.834	Sold to Austria-Hungary July 1917; turned over to France as war reparation in 1920 and broken up

Notes