Type UB II submarine

Last updated
SM UB 45.jpg
SM UB-45
Class overview
Builders
Operators
Preceded by UB I
Succeeded by UB III
Built19151916
In commission19151931
Completed38
Lost21
Scrapped17
General characteristics UB-18 - UB-47
Displacement
  • 263–279  t (259–275 long tons) surfaced
  • 292–305 t (287–300 long tons) submerged
Length36.13–36.90 m (118 ft 6 in – 121 ft 1 in) (o/a)
Beam4.36–4.37 m (14 ft 4 in – 14 ft 4 in)
Draught3.66–3.75 m (12 ft 0 in – 12 ft 4 in)
Installed power
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
Complement2 officers, 21 men
Armament

The UB II type submarine was a class of coastal U-boats built during World War I by the German Imperial Navy and Austro-Hungarian Navy. The Type UB II class was twice as large as the preceding type UB I in order to incorporate much needed improvements in performance and armament. The class was a single hull design with saddle tanks. The first batch of twelve Type UB II was ordered on 30 May 1915, before the last of the Type UB I was commissioned, and the first Type UB II was commissioned before the end of the year. In 1915 and 1916, a total of thirty were built in Gemany and eight more were built in Austria-Hungary where they were classified as the U-27-class. They operated in the English Channel, North Sea, the Mediterranean and Black Sea, but did not have enough range to patrol in the Western Approaches. Twenty German and one Austro-Hungarian Type UB II were lost during the war, the remainder were scrapped after the war, except for one that served in the French Navy and was scrapped in 1931.

Contents

Design

The design of Type UB II addressed many of the problems apparent in the preceding Type UB I class. The Type UB I had been too small and underpowered, it was not fast enough to chase fleeing merchants and it had not enough power to master the strong currents in the English Channel. When the single diesel broke down, the U-boat was helpless. The Type UB I did not have a deck gun to stop merchants. [1]

The Type 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. Type UB II U-boats retained the two bow torpedo tubes of the Type UB I, but could also store two reloads internally. The torpedo tubes were installed one above the other to allow for a bow design that would create optimal surface efficiency. A deck gun was installed before the conning tower. 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. The resulting larger beam meant that these U-boats were not transportable anymore by rail as the preceding Type UB I, but eventually some Type UB II were transported by rail to the Mediterranean Sea by disassembling them in longitudinal sections fitting the railroad gauge. Other improvements over the preceding Type UB I included forward hydroplanes, a second periscope operated from the central control room and a two masted wireless aerial. [2]

Construction

On 30 April 1915, six Type UB II ( UB-18 - UB-23 ) were ordered from the Blohm & Voss shipyard in Hamburg and one day later a further six ( UB-24 - UB-29 ) were ordered from AG Weser in Bremen. The main reason for building smaller coastal submarines rather than large fleet submarines, was the building time. A fleet submarine took more than one year to build which implied a risk that they would be completed only after the end of the hostilities, whilst these coastal submarines were expected to be delivered before the end of 1915. But when it became apparent that the war would last well into 1916, eightteen more Type UB II were ordered on 27 July 1915: UB-30 - UB-41 were ordered from Blohm & Voss, but were built by Reiherstieg shipyard as subcontractor from Blohm & Voss, and UB-42 - UB-47 were ordered from AG Weser. [2]

In August 1915 the Austro-Hungarian Navy acquired a licence from AG Weser to build Type UB II U-boats. For political reasons the building programme had to be split between the two components of the Austro-Hungarian empire: U-27 and U-28 were ordered from the Cantiere Navale Triestino in Pola which had an Austrian affiliation, and U-29 - U-32 from the Danubius yard in Trieste. which had a Hungarian affiliation. A further two U-boats were ordered from the Cantiere Navale Triestino in 1916: U-40 was ordered on 16 January and after the loss of U-6, U-41 was ordered as a substitute on 28 August. These U-boats were known as the U-27-class. [3] Because U-41 had the spare Grazer diesel engines of U-6 installed, she was 0.8 m (2.6 ft) longer, displaced 7 t (6.9 long tons) more on the surface, and 14 t (14 long tons) more submerged, than her sister ships. [4]

Characteristics

The four batches of German-built Type UB II U-boats had small variations in overall length, beam, draft and displacement. For all boats, the pressure hull had a length of 44.5 m (146 ft) and a maximum diameter of 4.70 m (15 ft 5 in). Constructional diving depth [a] was 50 m (164 ft 1 in). [6] They all had a complement of two officers and twenty-one men. [7] For submerged propulsion, all boats had two 100 kW (136 PS; 134 shp) Siemens-Schuckert electric motors, which gave a range of 45 nmi (83  km ; 52  mi ) at 4 knots (7.4  km/h ; 4.6  mph ). Diesel engines for surfaced propulsion came from three different producers and the yards had to install what was available. Daimler and Körting produced a six-cylinder, four-stroke RS206 engine providing 142 brake horsepower (106 kW), Benz produced the six-cylinder, four-stroke DS25u which provided 135 bhp (101  kW ). [8]

All German-built Type UB IIs had two 50 cm (20 in) bow torpedo tubes with two internal reloads, and UB-34, UB-35 and UB-41 had two extra external above-water torpedo launchers. UB-27, UB-34, UB-35 and UB-41 could also carry fourteen mines. UB-21, UB-22, UB-23 and UB-24 could be armed with mines untill 1916-1917, and UB-26 received the capability to carry mines only in 1916-1917. [9] The first Type UB II U-boats had a 5 cm SK L/40 deck gun, but later U-boats had a 8.8 cm SK L/30 installed. Some of the U-boats with a 5 cm gun had it later replaced by a 8.8 cm gun; in 1916 in preparation of a renewed U-boat offensive, all Type UB II U-boats of the Flanders U-boat flotilla had a 8.8 cm gun installed so that they were better equipped to attack shipping according to the Prize rules. [10]

The Austro-Hungarian Type UB II U-boats had a complement of five officers and fourteen men. These U-boats were equipped with two torpedo tubes and two torpedo reloads of the smaller 45 cm (18 in) size. They were also equipped with a 75 mm/26 (3.0 in) deck gun and an 8 mm (0.31 in) machine gun [4]

Differences in dimensions, speed, range and diesel engines [7] [11] [12]
batchUB-18 - UB-23UB-24 - UB-29UB-30 - UB-41UB-42UB-43 - UB-47U-27 - U-31, U-40U-41
displacement surfaced263 t (259 long tons)265 t (261 long tons)274 t (270 long tons)279 t (275 long tons)272 t (268 long tons)268 t (264 long tons)275 t (271 long tons)
displacement submerged292 t (287 long tons)291 t (286 long tons)303 t (298 long tons)303 t (298 long tons)305 t (300 long tons)306 t (301 long tons)320 t (310 long tons)
Length36.13 m (118.5 ft)36.90 m (121.1 ft)37.70 m (123.7 ft)
Beam4.36 m (14.3 ft)4.37 m (14.3 ft)
Draught3.70 m (12.1 ft)3.66 m (12.0 ft)3.69 m (12.1 ft)3.75 m (12.3 ft)3.68 m (12.1 ft)3.70 m (12.1 ft)3.72 m (12.2 ft)
speed surface9.15  kn (16.95 km/h; 10.53 mph)8.90 kn (16.48  km/h ; 10.24  mph )9.06 kn (16.78  km/h ; 10.43  mph )8.82 kn (16.33  km/h ; 10.15  mph )9 kn (17  km/h ; 10  mph )
speed submerged5.81 kn (10.76  km/h ; 6.69  mph )5.72 kn (10.59  km/h ; 6.58  mph )5.71 kn (10.57  km/h ; 6.57  mph )6.22 kn (11.52  km/h ; 7.16  mph )7.5 kn (13.9  km/h ; 8.6  mph )
range surface at 5 knots6,450 nmi
(11,950  km ; 7,420  mi )
7,200 nmi
(13,300  km ; 8,300  mi )
7,030 nmi
(13,020  km ; 8,090  mi )
6,940 nmi
(12,850  km ; 7,990  mi )
6,250 nmi
(11,580  km ; 7,190  mi )
diesel enginesDaimler RS206
UB-20, UB-23 : Körting
Benz DS25u
UB-26, UB-29 : Daimler RS206
Benz DS25u
UB-36, UB-28 - UB-41 : Körting
Daimler RS206Daimler RS206
U-30: Körting
Grazer

History

There were thirty Type UB II submarines commissioned into the German Imperial Navy and eight into the Austro-Hungarian Navy. Two German built boats, the UB-43 and UB-47 were sold to Austria-Hungaria on 30 july 1917, transported by rail to Pola at the Adriatic Sea, and were commissioned in the Austro-Hungarian Navy as U-43 and U-47 respectivily. [13]

List of Type UB II submarines built in Germany [14] [9]
namelaunchedcommissionedmerchant
ships sunk
(nbr/GRT)
Fate
UB-18 21 Augustus 191511 December 1915126 / 128.555Rammed and sunk by trawler Ben Lawer on 9 December 1917 in the English Channel.
UB-19 2 September 191517 December 191514 / 11.558Sunk by Q-ship HMS Penshurst on 30 November 1916 in the English Channel.
UB-20 20 September 191510 February 191613 / 9.914Struck a mine and sank during diving trial on 28 July 1917 off Flanders. [15]
UB-21 20 September 191520 February 191632 / 35.188Surrendered on 24 November 1918. Foundered on way to breakers in 1920.
UB-22 9 October 19152 March 191627 / 16.646Struck a mine on 19 January 1918 in the North Sea.
UB-23 9 October 191512 March 191651 / 34.322Interned at Corunna, Spain July 1917; broken up in 1921 in Brest.
UB-24 18 October 191518 November 1915noneSurrendered to France November 1918; broken up in 1921 in Brest.
UB-25 22 November 191511 December 1915noneSunk after collision with SMS V26 on 19 March 1917. Salvaged, surrendered to the Allies November 1918; broken up in 1922 at Canning Town.
UB-26 14 December 19157 January 1916noneSunk on 5 April 1916 in Le Havre. Raised by French Navy repaired as Roland Morillot. Scrapped in 1931.
UB-27 10 February 191623 February 191612 / 16.666Sunk by HMS Halcyon on 29 July 1917 in the North Sea.
UB-28 20 December 191527 December 1915noneSurrendered to Britain on 4 November 1918; broken up in 1919-1920 at Bo'ness.
UB-29 31 December 191518 January 191632 / 39.378Previously thought sunk by HMS Landrail, but likely mined December 1916 (wreck discovered and examined in 2017) [16]
UB-30 16 November 191518 March 191618 / 19.606Depth charged by five trawlers on 13 August 1918 in the North Sea near Whitby. [17]
UB-31 16 November 191525 March 191627 / 72.370Struck a mine on 2 May 1918 in the English Channel.
UB-32 4 December 191511 April 191622 / 42.889Possibly sunk by aircraft on 22 September 1917 in the English Channel, but was more likely sunk by a mine
UB-33 4 December 191522 April 191613 / 5.356Sunk by mines on 11 April 1918 in the English Channel on the Varne Bank
UB-34 28 December 191510 June 191631 / 39.219Surrendered on 26 November 1918; broken up 1922 in Canning Town.
UB-35 28 December 191522 June 191642 / 47.862Sunk by British warships including HMS Leven on 26 January 1918 in the English Channel.
UB-36 15 January 191622 May 192611 / 6.252Sunk by mines 21 May 1917 in the English Channel.
UB-37 28 December 191517 May 191630 / 20.500Sunk by Q-ship Penshurst on 14 January 1917 in the English Channel.
UB-38 1 April 191619 July 191643 / 45.210Struck a mine on 8 February 1918 in the English Channel
UB-39 29 December 191529 April 191693 / 89.810Mined on 18 May 1918 in the English Channel.
UB-40 25 April 191617 August 191699 / 131.680Scuttled on 5 October 1918 off Zeebrugge.
UB-41 6 May 191625 August 19168 / 8.387Mined on 15 October 1917 in the North Sea.
UB-42 4 March 191623 March 191610 / 13.184Surrendered on 26 November 1918; broken up in 1920 in Malta.
UB-43 8 April 191624 April 191622 / 99.202Sold to Austria-Hungary on 30 July 1917; turned over to France as war reparation in 1920 and broken up.
UB-44 20 April 191611 May 19161 / 3.409Missing after 8 August 1916 in the Ionian Sea.
UB-45 12 May 191626 May 19163 / 11.666Struck a mine on 6 November 1916 in the Black Sea.
UB-46 31 May 191612 June 19164 / 8.099Struck a Russian mine on 7 December 1916 in the Black Sea. Wreck raised in 1993 and put on display in Çanakkale Turkey.
UB-47 17 June 19164 July 191620 / 75.834Sold to Austria-Hungary 30 July 1917; turned over to France as war reparation in 1920 and broken up.
List of Type UB II submarines built in Austria-Hungary
namecommissioned [18] fate [4]
U-27 November 1916Surrendered to Italy, where she was broken up in 1920.
U-28 1916Surrendered to Italy and scrapped In Venice in 1920.
U-29 November 1916Surrendered to Italy, where she was broken up in 1920.
U-30 January 1917Missing after 17 March 1917.
U-31 March 1917Ceded to France after the war and scrapped in 1920.
U-32 April 1917Surrendered to Italy and scrapped In Venice in 1920.
U-40 May 1917Surrendered to Italy and scrapped In Venice in 1920.
U-41 May 1917Ceded to France after the war and scrapped.

Footnotes

Notes

  1. Constructional diving depth had a safety factor of 2.5, which meant that crushing depth was 2.5 times construction diving depth. [5]

Citations

  1. Termote 2014, p. 34.
  2. 1 2 Rössler 1981, p. 50.
  3. Möller & Brack 2004, p. 217.
  4. 1 2 3 Möller & Brack 2004, p. 227.
  5. Rössler 1981, p. 26.
  6. Rössler 1981, p. 332.
  7. 1 2 Herzog 1993, pp. 57–58.
  8. Möller & Brack 2004, pp. 44–45, 145.
  9. 1 2 Möller & Brack 2004, pp. 44–45.
  10. De Groot 2017, pp. 205–206.
  11. Gröner 1991, pp. 23–25.
  12. Möller & Brack 2004, pp. 44–45, 227.
  13. Möller & Brack 2004, pp. 44–45, 227–228.
  14. Herzog 1993, pp. 71–72.
  15. Termote 2014, pp. 242–243.
  16. Termote 2014, pp. 248–249.
  17. Termote 2014, pp. 249–250.
  18. Gibson & Prendergast 2003, pp. 386–387.

Bibliography

Further reading