Type UC II submarine

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.
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. 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.
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.

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 - and AG Vulcan in Hamburg received an order for a further nine U-boats -, 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 - were ordered from Blohm & Voss, a further six - from AG Vulcan and AG Weser in Hamburg received an order for three U-boats -. 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: - from Germaniawerft, - from Kaiserliche Werft Danzig, - from AG Weser, - from Blohm & Voss and - from Vulcan.

Characteristics

Dimensions

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, 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. Constructional diving depth was.

batch	length overall m	length pressure hull m	draft m	displacement surfaced tonnes	displacement submerged tonnes
UC-16 - UC-24
UC-25 - UC-33
UC-34 - UC-39
UC-40 - UC-45
UC-46 - UC-48
UC-49 - UC-54
UC-55 - UC-60
UC-61 - UC-64
UC-65 - UC-73
UC-74 - UC-79

Propulsion

For surfaced propulsion, five types of six-cylinder, four-stroke diesel engines were used: Daimler produced the MU256 engine providing, Körting produced an engine providing, Benz produced the OS32 which provided and MAN produced the S6V23/34 and the S6V26/36. For submerged propulsion, the first five Type UC II batches had two combined motor/generators of each installed, whilst the last five batches had 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:

batch	variations	speed surfaced	speed submerged	range surfaced	range submerged	diesel	electrical
UC-16 - UC-24						MAN S6V23/24	BBC 170 kW
UC-25 - UC-33	UC-25 - UC-27					MAN S6V23/24	SSW 170 kW
UC-25 - UC-33	UC-28 - UC-30					Daimler MU256	SSW 170 kW
UC-25 - UC-33	UC-31 - UC-33					MAN S6V23/24	SSW 170 kW
UC-34 - UC-39	UC-34 - UC-36					MAN S6V23/24	SSW 170 kW
UC-34 - UC-39	UC-37 - UC-39					MAN S6V26/36	SSW 170 kW
UC-40 - UC-45						Körting	SSW 170 kW
UC-46 - UC-48						MAN S6V26/36	SSW 170 kW
UC-49 - UC-54	UC-49 - UC-50					Benz	BBC 230 kW
UC-49 - UC-54	UC-51 - UC-54					Daimler MU256	BBC 230 kW
UC-55 - UC-60	UC-55 - UC-57					Benz	BBC 230 kW
UC-55 - UC-60	UC-58 - UC-60					Daimler MU256	BBC 230 kW
UC-61 - UC-64						MAN S6V26/36	SSW 230 KW
UC-65 - UC-73						MAN S6V26/36	SSW 230 KW
UC-74 - UC-79	UC-74 - UC-75					Benz	SSW 230 KW
UC-74 - UC-79	UC-76 - UC-79					Daimler MU256	SSW 230 KW

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. The bow compartment contained six mine shafts which contained three UC 120 mines each. The UC 120 was an anchored mine with contact fuzes and contained 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. 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.

List of Type UC II submarines

There were 64 Type UC II submarines commissioned into the Imperial German Navy.

Name	Date launched	Date Commissioned	Fate
	1 February 1916	26 June 1916	Mined off Zeebrugge in October 1917
	19 February 1916	23 July 1916	Surrendered on 26 November 1918 and scrapped in 1920 at Preston
	4 March 1916	15 August 1916	Sunk on 19 February 1917 in the English Channel
	15 March 1916	22 August 1916	Sunk on 6 December 1916 South of Ireland
	1 April 1916	8 September 1916	Surrendered on 19 January 1919 and scrapped in 1920 at Preston
	1 April 1916	15 September 1916	Missing in October 1917
	1 February 1916	1 July 1916	Surrendered on 3 February 1919 and scrapped in 1921 at Landerneau
	19 February 1916	28 July 1916	Surrendered on 14 November 1918 and scrapped in 1921 at Bizerta
	4 March 1916	17 August 1916	Sunk on 24 May 1917 in the Adriatic Sea
	10 June 1916	28 June 1916	Scuttled on 29 October 1918 off Pola
	22 June 1916	18 July 1916	Sunk on 9 May 1917 off Cape Griz Nez
	28 June 1916	25 July 1916	Surrendered on 3 February 1917 and scrapped in 1921 at Landerneau
	8 July 1916	6 August 1916	Surrendered on 19 February 1919 and scrapped
	15 July 1916	15 August 1916	Lost on 7 June 1917 South of Ireland
	27 July 1916	22 August 1916	Missing in October 1917
	7 August 1916	2 September 1916	Surrendered on 3 February 1919 and scrapped in 1921 at Landerneau
	12 August 1916	13 September 1916	Surrendered on 14 November 1918 and scrapped in 1921 at Bizerta
	26 August 1916	25 September 1916	Lost on 24 May 1917 in the Adriatic Sea
	6 May 1916	26 September 1916	Scuttled on 30 October 1918 off Pola
	6 May 1916	4 October 1916	Lost 16 May 1918 off the coast off South Sardinia
	25 June 1916	3 November 1916	Lost in May 1917 in the English Channel
	5 June 1916	13 October 1916	Surrendered in 1919 and scrapped in 1920 in Malta
	5 June 1916	19 October 1916	Lost 13 December 1917 in the Gulf of Corinth
	25 June 1916	29 October 1915	Lost 8 February 1917 in the Nort Sea
	5 September 1916	1 October 1916	Sunk on 19 December 1919 in the North Sea
	13 September 1916	11 October 1916	Lost on 21 August 1917 in the North Sea
	21 September 1916	18 November 1916	Lost on 10 September 1917 off the coast of South Ireland
	5 October 1916	25 October 1916	Sunk on 11 March 1917 in the Atlantic Ocean
	10 October 1916	4 November 1916	Sunk on 4 August 1917 off the coast of South Ireland. Raised and scrapped
	20 October 1916	18 November 1916	Sunk on 17 September 1917. Raised and surrendered in 1918. Scrapped in 1920 at Preston
	15 July 1916	15 September 1916	Lost on 8 February 1917 in the English Channel
	30 August 1916	13 October 1916	Lost on 18 November 1917 in the North Sea
	27 September 1915	6 November 1916	Interned in Spain, scuttled on 15 March 1919
	7 November 1916	2 December 1916	Lost on 8 August 1918 off Berry Head
	23 November 1916	21 December 1916	Lost on 4 February 1918 in the Bay of Biscay
	5 December 1916	6 january 1917	Lost on 17 November 1917 in the English Channel
	23 January 1917	15 March 1917	Surrendered on 16 January 1919 and scrapped in 1920 at Morecambe
	27 February 1917	5 April 1917	Scuttled on 28 October 1918 at Pola
	20 March 1917	10 May 1917	Scuttled on 28 October 1918 at Trieste
	2 August 1916	15 November 1916	Lost on 28 September 1918 at Lerwick
	26 August 1916	18 December 1916	Surrendered on 26 March 1919 and scrapped in 1923 at Rochefort
	7 September 1916	22 January 1917	Missing in November 1917
	21 October 1916	12 March 1917	Surrendered on 24 November 1918 and scrapped in 1921 in Cherbourg
	28 September 1916	12 May 1917	Surrendered on 21 November 1918 and scrapped in 1919-20 in Bo'ness
	8 November 1916	25 June 1917	Surrendered on 23 FEbruary 1919 and scrapped in 1921 at Rainham
	11 November 1916	13 December 1916	Scuttled on 26 July 1917 in the English Channel after running aground
	9 December 1916	8 January 1917	Missing in October 1917 in the English Channel
	6 January 1917	30 January 1917	Lost on 1 November 1917 in the English Channel
	27 January 1917	22 February 1917	Lost on 20 June 1918 in the English Channel
	8 June 1916	10 November 1916	Lost on 3 November 1917 in the English Channel
	15 June 1916	18 November 1916	Lost on 12 June 1917 in the English Channel
	6 August 1916	10 December 1916	Surrendered on 16 January 1919 and scrapped in 1919-20 at Briton Ferry
	12 August 1916	17 December 1916	Lost on 13 March 1917 off Start Point
	12 August 1916	23 December 1916	Lost on 6 December 1917 in the English Channel
	7 August 1916	22 November 1916	Lost on 28 August 1918 in the North Sea
	7 August 1916	28 November 1916	Sunk on 20 January 1919 on the way to surrender
	12 August 1916	5 December 1916	Lost on 20 August 1918 in the Bay of Biscay
	26 August 1916	24 December 1916	Surrendered on 16 January 1919 and scrapped in 1920 at Briton Ferry.
	19 October 1916	26 November 1916	Surrendered on 26 March 1919 and scrapped in 1921 at Toulon
	6 November 1916	6 December 1916	Lost on 31 May 1918 in the Nort Sea
	25 November 1916	17 December 1916	Surrendered on 1 December 1918 and scrapped in 1920-21 at Briton Ferry
	2 December 1916	29 December 1916	Missing in July 1918 in the English Channel
	8 December 1916	10 January 1917	Lost on 2 May 1918 in the English Channel
	19 December 1916	22 January 1917	Lost on 19 April 1918 in the English Channel