Type UC II submarine

Two Type UC II submarines alongside Austro-Hungarian depot ship Amphitrite at Gjenovic, Bocche di Cattaro, in the Adriatic Sea
Class overview
Builders	AG Weser, Bremen Blohm & Voss, Hamburg Vulcan, Hamburg Germaniawerft, Kiel Kaiserliche Werft Danzig
Operators	Imperial German Navy
Preceded by	UC I
Succeeded by	UC III
Cost	1,729,000–2,141,000 German Mark
Built	1916–1917
In commission	1916–1918
Planned	64
Building	64
Completed	64
Lost	46
General characteristics
Type	Coastal minelaying submarine
Displacement	400–434  t (394–427 long tons) surfaced 480–511 t (472–503 long tons) submerged
Length	49.35–53.15 m (161 ft 11 in – 174 ft 5 in) o/a
Beam	5.22 m (17 ft 2 in)
Draught	3.65 m (12 ft)
Propulsion	2 shafts 2 6-cylinder diesel engines, 500–660 PS (370–490 kW; 490–650 shp) 2 electric motors, 340–460 kW (460–630 PS)
Speed	11.6–12 knots (21.5–22.2 km/h; 13.3–13.8 mph) surfaced 6.7–7.4 knots (12.4–13.7 km/h; 7.7–8.5 mph) submerged
Range	7,280–10,040 mi (11,720–16,160 km) at 7 knots (13 km/h; 8.1 mph) surfaced 52–60 mi (84–97 km) at 4 knots (7.4 km/h; 4.6 mph) submerged
Complement	3 officers, 23 enlisted
Armament	3 × 50 cm (19.7 in) torpedo tubes ( 2 external bow and 1 internal stern ) with 7 torpedoes 1 × 8.8 cm (3.5 in) SK L/30 or 10.5 cm (4.1 in) SK L/45 deck gun 18 × Type UC 200 mines in 6 chutes

The Type UC II submarine was a class of coastal minelaying U-boats designed and built for the Imperial German Navy during World War I. They were a significant improvement over the preceding Type UC I in armament, range and seaking abilities. Construction began in 1915 and by mid-1917 64 Type UC II had been delivered by five shipyards in ten different batches, which had variations in dimensions and performance. By the end of the war, 46 Type UC II were lost. The Type UC II was a very successful design combining torpedo, deck gun and mine armament with a sufficient performance and range to operate around Great Britain. A succeeding Type UC III was ordered and built in large numbers but came too late to see service in World War I.

Design

In the summer of 1916 some restrictions were imposed on the unrestricted submarine warfare campaign, and minelaying became more significant. The Type UC I minelayer had proven its value and that U-boat design had fulfilled the expectations, but it had its limitations: The Type UC I was underpowered and had problems operating in the strong currents of the English Channel, it had only one diesel engine so when that engine broke down the boat was helpless and the lack of a deck gun and torpedo tube made it impossible to attack any enemy ship encountered whilst on minelying mission. ^{[1] [2]}

In order to tackle these problems and to fullfill the extra requirement of being able to sail independenty to the Mediterranean Sea instead of being disassembled and transported by rail, a much larger Type UC II was designed. The Type UC II was equipped with the same UC/200 mines as the Type UC I, and mounted the same number of inclined mine shafts going through the pressure hull. Because of the larger hull, and by raising the forward deck, these mine shafts were longer and could store three instead of two mines. ^[3] In order to give the Type UC II also offensive armament, a torpedo compartment with one torpedo tube was installed on the stern after the engine compartment. As the mine shafts occupied the complete bow compartment, two bow torpedo tubes were mounted externally besides the raised mineshaft deck. A deck gun was installed between the raised foredeck and the conning tower. ^[2]

Although the combination of mines, torpedo and deck gun, the extended range and increased surface speed, made this Type UC II one of the most efficient U-boat designs, there were some drawbacks: the raised forecastle made the boat more difficult to handle, especially when wind was above Force 5. This raised bow made diving also more difficult and slow, although the thirty-five to forthy second diving time were considered given the circumstances. A third drawback of the raised bow was that the deck gun was awash in rough seas, and spray made watchkeeping on the conning tower difficult even in moderate weather. These problems were addressed in the subsequent Type UC III, but this type did not become operational before the end of the war. ^[4]

Construction

On 21 August 1915 the first two batches of Type UC II were ordered: Blohm & Voss in Hamburg received an order for nine Type UC II UC-16 - UC-24 and AG Vulcan in Hamburg received an order for a further nine U-boats UC-25 - UC-33, with expected delivery date between March and June 1916. After the cessation of the first unrestricted submarine warfare campaign on 19 September 1915, the way of enforcing the blockade of Great Britain shifted even more towards minelaying, and on 9 November 1915 the German Navy decided to build as many Type UC II as could be build by September 1916. Six more Type UC II UC-34 - UC-39 were ordered from Blohm & Voss, a further six UC-40 - UC-45 from AG Vulcan and AG Weser in Hamburg received an order for three U-boats UC-46 - UC-48. In January 1916, the head of the German Navy Alfred von Tirpitz ordered the construction work on ships which would not be finished before October 1916, be delayed in order to free up capacity for further Type UC II construction. Five more batches were ordered on 11 January 1916: UC-49 - UC-54 from Germaniawerft, UC-55 - UC-60 from Kaiserliche Werft Danzig, UC-61 - UC-64 from AG Weser, UC-65 - UC-73 from Blohm & Voss and UC-74 - UC-79 from Vulcan. ^[5]

Characteristics

Dimensions

The UC-56 was interned in Spain in March 1918

All ten Type UC II batches had small variations in overall length, length of the pressure hull, draft and displacement. All Type UC II had a beam of 5.22 (17.1), a complement of three officers and twenty-three enlisted men. One reason for the variations in overall length was the different form of the bow, which in early versions was rounded, whilst later versions had a sharp nose, with many boats receiving the modification from rounded to pointed bow after construction. ^{[6] [7]} Constructional diving depth ^[a] was 50 (160). ^[9]

variations in dimensions of the Type UC II ^[6]

batch	length overall m (ft)	length pressure hull [7] m (ft)	draft m (ft)	displacement surfaced tonnes (long tons)	displacement submerged tonnes (long tons)
UC-16 - UC-24	52.15 (171.1)	39.30 (128.9)	3.68 (12.1)	417 (410)	493 (485)
UC-25 - UC-33	51.12 (167.7)	39.30 (128.9)	3.68 (12.1)	400 (390)	480 (470)
UC-34 - UC-39	53.15 (174.4)	40.30 (132.2)	3.65 (12.0)	427 (420)	509 (501)
UC-40 - UC-45	51.11 (167.7)	40.30 (132.2)	3.68 (12.1)	400 (390)	480 (470)
UC-46 - UC-48	51.85 (170.1)	39.70 (130.2)	3.67 (12.0)	420 (410)	502 (494)
UC-49 - UC-54	52.69 (172.9)	40.96 (134.4)	3.64 (11.9)	434 (427)	511 (503)
UC-55 - UC-60	52.67 (172.8)	40.86 (134.1)	3.61 (11.8)	415 (408)	498 (490)
UC-61 - UC-64	51.85 (170.1)	39.70 (130.2)	3.67 (12.0)	422 (415)	504 (496)
UC-65 - UC-73	53.15 (174.4)	40.30 (132.2)	3.64 (11.9)	427 (420)	508 (500)
UC-74 - UC-79	52.11 (171.0)	40.30 (132.2)	3.65 (12.0)	410 (400)	493 (485)

Propulsion

For surfaced propulsion, five types of six-cylinder, four-stroke diesel engines were used: Daimler produced the MU256 engine providing 330 brake horsepower (250 kW), Körting produced an engine providing 260 bhp (190 kW) ^[b] , Benz produced the OS32 which provided 300 bhp (220  kW ) and MAN produced the 250 bhp (190 kW) S6V23/34 and the 300 bhp (220 kW) S6V26/36. ^[10] For submerged propulsion, the first five Type UC II batches had two combined motor/generators of 170 kW (231 PS; 228 shp) each installed, whilst the last five batches had 230 kW (313 PS; 308 shp) combined motor/generators. Both types were produced by Siemens-Schuckert and by Brown, Boveri & Cie as well. Combined with the variations in dimensions, these variations in propulsion affected speed and range: ^[6]

variations in speed and range of the Type UC II ^[6]

batch	variations	speed surfaced	speed submerged	range surfaced	range submerged	diesel	electrical
UC-16 - UC-24		11.6 kn 21.5 km/h; 13.3 mph	7.0 kn (13.0 km/h; 8.1 mph)	9,430 nmi (17,460 km; 10,850 mi)	55 nmi (102 km; 63 mi)	MAN S6V23/24	BBC 170 kW
UC-25 - UC-33	UC-25 - UC-27	11.6 kn 21.5 km/h; 13.3 mph	6.7 kn (12.4 km/h; 7.7 mph)	9,260 nmi (17,150 km; 10,660 mi)	53 nmi (98 km; 61 mi)	MAN S6V23/24	SSW 170 kW
	UC-28 - UC-30			9,410 nmi (17,430 km; 10,830 mi)		Daimler MU256
	UC-31 - UC-33			10,040 nmi (18,590 km; 11,550 mi)		MAN S6V23/24
UC-34 - UC-39	UC-34 - UC-36	11.9 kn 22.0 km/h; 13.7 mph	6.8 kn 12.6 km/h; 7.8 mph	10,108 nmi (18,720 km; 11,632 mi)	54 nmi (100 km; 62 mi)	MAN S6V23/24	SSW 170 kW
	UC-37 - UC-39					MAN S6V26/36
UC-40 - UC-45		11.7 kn (21.7 km/h; 13.5 mph)	6.7 kn (12.4 km/h; 7.7 mph)	9,410 nmi (17,430 km; 10,830 mi)	60 nmi (110 km; 69 mi)	Körting	SSW 170 kW
UC-46 - UC-48		11.7 kn (21.7 km/h; 13.5 mph)	6.9 kn (12.8 km/h; 7.9 mph)	7,280 nmi (13,480 km; 8,380 mi)	54 nmi (100 km; 62 mi)	MAN S6V26/36	SSW 170 kW
UC-49 - UC-54	UC-49 - UC-50	11.8 kn (21.9 km/h; 13.6 mph)	7.2 kn (13.3 km/h; 8.3 mph)	8,820 nmi (16,330 km; 10,150 mi)	56 nmi (104 km; 64 mi)	Benz [c]	BBC 230 kW
	UC-51 - UC-54					Daimler MU256
UC-55 - UC-60	UC-55 - UC-57	11.6 kn 21.5 km/h; 13.3 mph	7.3 kn (13.5 km/h; 8.4 mph)	8,660 nmi (16,040 km; 9,970 mi)	52 nmi (96 km; 60 mi)	Benz [c]	BBC 230 kW
	UC-58 - UC-60			9,450 nmi (17,500 km; 10,870 mi)		Daimler MU256
UC-61 - UC-64		11.9 kn (22.0 km/h; 13.7 mph)	7.2 kn (13.3 km/h; 8.3 mph)	8,000 nmi (15,000 km; 9,200 mi)	59 nmi (109 km; 68 mi)	MAN S6V26/36	SSW 230 KW
UC-65 - UC-73		12 kn (22 km/h; 14 mph)	7.4 kn (13.7 km/h; 8.5 mph)	10,420 nmi (19,300 km; 11,990 mi)	52 nmi (96 km; 60 mi)	MAN S6V26/36	SSW 230 KW
UC-74 - UC-79	UC-74 - UC-75	11.8 kn (21.9 km/h; 13.6 mph)	7.3 kn (13.5 km/h; 8.4 mph)	10,420 nmi (19,300 km; 11,990 mi)	52 nmi (96 km; 60 mi)	Benz [c]	SSW 230 KW
	UC-76 - UC-79					Daimler MU256

Armament

Type UC II U-boats had two external torpedo tubes which could only be fired whilst submerged, and one internal torpedo tube aft. The aft torpedo compartment was very small; the two spare torpedoes had to disassembled in three parts for stowage. The external torpedo tubes had one spare torpedo each, which was also stored externally above the ballast tanks on the side, behind the torpedo tube. ^[11] The bow compartment contained six 100-centimetre (39 in) mine shafts which contained three UC 120 mines each. The UC 120 was an anchored mine with contact fuzes and contained 120 kg (260 lb) of TNT explosives. The mine shafts were open and were integrated in the pressure hull so the mines were kept in wet storage and consequently the depth setting of the mines had to be fixed before the patrol and could not be altered anymore during the patrol. ^[12] As constructed, the Type UC II received a 8.8 cm SK L/30 deck gun which was in 1918 replaced with a 10.5 cm SK L/45 on some boats. ^[6]

List of Type UC II submarines

There were 64 Type UC II submarines commissioned into the Imperial German Navy. ^[6]

Name	Date launched [13]	Date Commissioned [13]	Fate [6]
UC-16	1 February 1916	26 June 1916	Mined off Zeebrugge in October 1917
UC-17	19 February 1916	23 July 1916	Surrendered on 26 November 1918 and scrapped in 1920 at Preston
UC-18	4 March 1916	15 August 1916	Sunk on 19 February 1917 in the English Channel
UC-19	15 March 1916	22 August 1916	Sunk on 6 December 1916 South of Ireland
UC-20	1 April 1916	8 September 1916	Surrendered on 19 January 1919 and scrapped in 1920 at Preston
UC-21	1 April 1916	15 September 1916	Missing in October 1917
UC-22	1 February 1916	1 July 1916	Surrendered on 3 February 1919 and scrapped in 1921 at Landerneau
UC-23	19 February 1916	28 July 1916	Surrendered on 14 November 1918 and scrapped in 1921 at Bizerta
UC-24	4 March 1916	17 August 1916	Sunk on 24 May 1917 in the Adriatic Sea
UC-25	10 June 1916	28 June 1916	Scuttled on 29 October 1918 off Pola
UC-26	22 June 1916	18 July 1916	Sunk on 9 May 1917 off Cape Griz Nez
UC-27	28 June 1916	25 July 1916	Surrendered on 3 February 1917 and scrapped in 1921 at Landerneau
UC-28	8 July 1916	6 August 1916	Surrendered on 19 February 1919 and scrapped
UC-29	15 July 1916	15 August 1916	Lost on 7 June 1917 South of Ireland
UC-30	27 July 1916	22 August 1916	Missing in October 1917
UC-31	7 August 1916	2 September 1916	Surrendered on 3 February 1919 and scrapped in 1921 at Landerneau
UC-32	12 August 1916	13 September 1916	Surrendered on 14 November 1918 and scrapped in 1921 at Bizerta
UC-33	26 August 1916	25 September 1916	Lost on 24 May 1917 in the Adriatic Sea
UC-34	6 May 1916	26 September 1916	Scuttled on 30 October 1918 off Pola
UC-35	6 May 1916	4 October 1916	Lost 16 May 1918 off the coast off South Sardinia
UC-36	25 June 1916	3 November 1916	Lost in May 1917 in the English Channel
UC-37	5 June 1916	13 October 1916	Surrendered in 1919 and scrapped in 1920 in Malta
UC-38	5 June 1916	19 October 1916	Lost 13 December 1917 in the Gulf of Corinth
UC-39	25 June 1916	29 October 1915	Lost 8 February 1917 in the Nort Sea
UC-40	5 September 1916	1 October 1916	Sunk on 19 December 1919 in the North Sea
UC-41	13 September 1916	11 October 1916	Lost on 21 August 1917 in the North Sea
UC-42	21 September 1916	18 November 1916	Lost on 10 September 1917 off the coast of South Ireland
UC-43	5 October 1916	25 October 1916	Sunk on 11 March 1917 in the Atlantic Ocean
UC-44	10 October 1916	4 November 1916	Sunk on 4 August 1917 off the coast of South Ireland. Raised and scrapped
UC-45	20 October 1916	18 November 1916	Sunk on 17 September 1917. Raised and surrendered in 1918. Scrapped in 1920 at Preston
UC-46	15 July 1916	15 September 1916	Lost on 8 February 1917 in the English Channel
UC-47	30 August 1916	13 October 1916	Lost on 18 November 1917 in the North Sea
UC-48	27 September 1915	6 November 1916	Interned in Spain, scuttled on 15 March 1919
UC-49	7 November 1916	2 December 1916	Lost on 8 August 1918 off Berry Head
UC-50	23 November 1916	21 December 1916	Lost on 4 February 1918 in the Bay of Biscay
UC-51	5 December 1916	6 january 1917	Lost on 17 November 1917 in the English Channel
UC-52	23 January 1917	15 March 1917	Surrendered on 16 January 1919 and scrapped in 1920 at Morecambe
UC-53	27 February 1917	5 April 1917	Scuttled on 28 October 1918 at Pola
UC-54	20 March 1917	10 May 1917	Scuttled on 28 October 1918 at Trieste
UC-55	2 August 1916	15 November 1916	Lost on 28 September 1918 at Lerwick
UC-56	26 August 1916	18 December 1916	Surrendered on 26 March 1919 and scrapped in 1923 at Rochefort
UC-57	7 September 1916	22 January 1917	Missing in November 1917
UC-58	21 October 1916	12 March 1917	Surrendered on 24 November 1918 and scrapped in 1921 in Cherbourg
UC-59	28 September 1916	12 May 1917	Surrendered on 21 November 1918 and scrapped in 1919-20 in Bo'ness
UC-60	8 November 1916	25 June 1917	Surrendered on 23 FEbruary 1919 and scrapped in 1921 at Rainham
UC-61	11 November 1916	13 December 1916	Scuttled on 26 July 1917 in the English Channel after running aground
UC-62	9 December 1916	8 January 1917	Missing in October 1917 in the English Channel
UC-63	6 January 1917	30 January 1917	Lost on 1 November 1917 in the English Channel
UC-64	27 January 1917	22 February 1917	Lost on 20 June 1918 in the English Channel
UC-65	8 June 1916	10 November 1916	Lost on 3 November 1917 in the English Channel
UC-66	15 June 1916	18 November 1916	Lost on 12 June 1917 in the English Channel
UC-67	6 August 1916	10 December 1916	Surrendered on 16 January 1919 and scrapped in 1919-20 at Briton Ferry
UC-68	12 August 1916	17 December 1916	Lost on 13 March 1917 off Start Point
UC-69	12 August 1916	23 December 1916	Lost on 6 December 1917 in the English Channel
UC-70	7 August 1916	22 November 1916	Lost on 28 August 1918 in the North Sea
UC-71	7 August 1916	28 November 1916	Sunk on 20 January 1919 on the way to surrender
UC-72	12 August 1916	5 December 1916	Lost on 20 August 1918 in the Bay of Biscay
UC-73	26 August 1916	24 December 1916	Surrendered on 16 January 1919 and scrapped in 1920 at Briton Ferry.
UC-74	19 October 1916	26 November 1916	Surrendered on 26 March 1919 and scrapped in 1921 at Toulon
UC-75	6 November 1916	6 December 1916	Lost on 31 May 1918 in the Nort Sea
UC-76	25 November 1916	17 December 1916	Surrendered on 1 December 1918 and scrapped in 1920-21 at Briton Ferry
UC-77	2 December 1916	29 December 1916	Missing in July 1918 in the English Channel
UC-78	8 December 1916	10 January 1917	Lost on 2 May 1918 in the English Channel
UC-79	19 December 1916	22 January 1917	Lost on 19 April 1918 in the English Channel

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. ^[8]
2. Möller & Brack give this engine 270 horsepower on p.58 and 260 horsepower on p.145
3. Möller mentions a 300 horsepower engine from Körting, but the Benz engine has 300 horsepower, not the Körting

Citations

1. Rössler 1981, p. 50.
2. Termote 2014, p. 50.
3. Rössler 1981, pp. 50–53.
4. Termote 2014, p. 50-53.
5. Rössler 1981, p. 53.
6. Möller & Brack 2004, pp. 56–62.
7. Herzog 1993, pp. 62–64.
8. Rössler 1981, p. 26.
9. Rössler 1981, p. 332.
10. Möller & Brack 2004, pp. 145–146.
11. Termote 2014, p. 86.
12. Termote 2014, pp. 45, 50, 91–92.
13. Herzog 1993, pp. 75–76.

Bibliography

• Herzog, Bodo (1993). Deutsche U-Boote : 1906 - 1966[German U-boats : 1906 - 1966] (in German). Erlangen: Müller. ISBN   9783860700365.
• Möller, Eberhard; Brack, Werner (2004). The Encyclopedia of U-Boats. London: Chatham. ISBN   1-85367-623-3.
• Rössler, Eberhard (1981). The U-boat: The evolution and technical history of German submarines. London: Cassell & Co. ISBN   0-304-36120-8.
• Termote, Tomas (2014). Oorlog onder Water, Unterseeboots Flottille Flandern 1915-1918[War below sea, submarine flottille Flanders 1915-1918] (in Dutch). Leuven: Davidsfonds. ISBN   978-90-5908-526-8.

Further reading

• De Groot, Bas (2017). Het Duitse Marinekorps in Vlaanderen 1914-1918. De land-, zee- en luchtoorlog[The German Naval Corps in Flanders 1914-1918. The war at land, on the sea and in the air.] (in Dutch). Soesterberg: Aspekt. ISBN   9789463380478.
• Gibson, R. H; Prendergast, Maurice (2003) [1931]. The German Submarine War, 1914–1918. Annapolis, Maryland: Naval Institute Press. ISBN   1591143144.

• Gröner, Erich; Jung, Dieter; Maass, Martin (1991). German Warships 1815–1945, U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN   0-85177-593-4.
• Conway's All the World's Fighting Ships 1906–1921