SM UC-21 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 29 August 1915 and was launched on 1 April 1916. She was commissioned into the German Imperial Navy on 12 September 1916 as SM UC-21.[1]
In eleven patrols UC-21 was credited with sinking 98 ships, either by torpedo or by mines laid. They included the British hospital ship, which UC-21 torpedoed in the English Channel on 17 April 1917, killing 29 already wounded soldiers and 12 crew.[2]
UC-21 disappeared after departing Zeebrugge for the Bay of Biscay on 13 September 1917.
Like all pre-UC-25 Type UC II submarines, UC-21 had a displacement of 417t when at the surface and 493t while submerged. She had a total length of 49.35m (161.91feet), a beam of 5.22m (17.13feet), and a draught of 3.650NaN0. The submarine was powered by two six-cylinder four-stroke diesel engines each producing 250PS (a total of 500PS), two electric motors producing 460PS, and two propeller shafts. She had a dive time of 35 seconds and was capable of operating at a depth of .
The submarine had a maximum surface speed of and a submerged speed of . When submerged, she could operate for at ; when surfaced, she could travel at . UC-21 was fitted with six mine tubes, eighteen UC 200 mines, three torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8sp=usNaNsp=us Uk L/30 deck gun. Her complement was twenty-six crew members.
Date | Name | Nationality | Tonnage[3] | Fate[4] | |
---|---|---|---|---|---|
28 November 1916 | Clematis | United Kingdom | 22 | Sunk | |
28 November 1916 | Lady of the Lake | United Kingdom | 91 | Sunk | |
28 November 1916 | Vulcan | United Kingdom | 27 | Sunk | |
28 November 1916 | HMD Pelagia | 84 | Sunk | ||
30 November 1916 | Draupner | Norway | 1,126 | Sunk | |
30 November 1916 | Eggesford | United Kingdom | 4,414 | Damaged | |
30 November 1916 | Therese | France | 165 | Sunk | |
1 December 1916 | King Bleddyn | United Kingdom | 4,387 | Sunk | |
2 December 1916 | Demetrios Inglesis | Greece | 2,088 | Sunk | |
2 December 1916 | Robinson | France | 186 | Sunk | |
2 December 1916 | Uribitarte | Spain | 1,756 | Sunk | |
3 December 1916 | Aiglon | France | 280 | Sunk | |
3 December 1916 | Louise | France | 155 | Sunk | |
3 December 1916 | Verdun | France | 184 | Sunk | |
4 December 1916 | Pallas | 1,202 | Sunk | ||
5 December 1916 | Nexos | Denmark | 1,013 | Sunk | |
6 December 1916 | Gerona | Spain | 1,328 | Sunk | |
7 December 1916 | Avristan | United Kingdom | 3,818 | Sunk | |
8 December 1916 | HMT Dagon | 250 | Sunk | ||
8 December 1916 | Falk | Norway | 1,379 | Sunk | |
8 December 1916 | Marjolaine | France | 163 | Sunk | |
8 December 1916 | Modum | Norway | 2,937 | Sunk | |
17 December 1916 | Margaret | United Kingdom | 54 | Sunk | |
18 January 1917 | 778 | Damaged | |||
19 January 1917 | Joseph Rosalie | France | 138 | Sunk | |
19 January 1917 | Marietta Di Giorgio | Norway | 988 | Sunk | |
19 January 1917 | Tremeadow | United Kingdom | 3,653 | Sunk | |
20 January 1917 | Kisagata Maru No. 3 | Japan | 2,588 | Sunk | |
20 January 1917 | Jotunfjell | Norway | 2,492 | Damaged | |
21 January 1917 | Victoire | France | 290 | Damaged | |
21 January 1917 | Leontine | France | 124 | Sunk | |
21 January 1917 | Saint Pierre | France | 127 | Sunk | |
22 January 1917 | Bearnais | France | 301 | Sunk | |
22 January 1917 | Precurseur | France | 364 | Sunk | |
22 January 1917 | Steinmachos | Greece | 1,175 | Sunk | |
24 January 1917 | Dan | Denmark | 1,869 | Sunk | |
24 January 1917 | Gladiateur | France | 23 | Sunk | |
24 January 1917 | Loire III | France | 27 | Sunk | |
24 January 1917 | Marie 3 | France | 25 | Sunk | |
24 January 1917 | Quebec | France | 3,346 | Sunk | |
24 January 1917 | Vega | Denmark | 195 | Sunk | |
25 January 1917 | Myrdal | Norway | 2,631 | Sunk | |
1 February 1917 | Sainte Helene | France | 2,128 | Sunk | |
10 February 1917 | Beechtree | United Kingdom | 1,277 | Sunk | |
11 February 1917 | Dernes | Norway | 738 | Sunk | |
12 February 1917 | Nordcap | Norway | 332 | Sunk | |
13 February 1917 | Progreso | Norway | 1,620 | Sunk | |
14 February 1917 | Longscar | United Kingdom | 2,777 | Sunk | |
14 February 1917 | Mar Adriatico | Spain | 2,410 | Sunk | |
15 February 1917 | Aline | France | 30 | Sunk | |
15 February 1917 | Marion Dawson | United Kingdom | 2,300 | Sunk | |
16 February 1917 | Niobe | France | 1,319 | Sunk | |
16 February 1917 | Pollcrea | United Kingdom | 1,209 | Damaged | |
17 February 1917 | Cabo | Norway | 1,254 | Sunk | |
17 February 1917 | Silene | France | 171 | Sunk | |
18 February 1917 | Triumph | United Kingdom | 52 | Sunk | |
19 February 1917 | Rutenfjell | Norway | 1,844 | Sunk | |
10 March 1917 | Asbjørn | Norway | 3,459 | Sunk | |
12 March 1917 | Alice Charles | France | 41 | Sunk | |
12 March 1917 | Arethuse | France | 40 | Sunk | |
13 March 1917 | Girda | Norway | 1,824 | Sunk | |
13 March 1917 | Vivina | Spain | 3,034 | Sunk | |
14 March 1917 | Blaamanden | Norway | 954 | Sunk | |
14 March 1917 | La Marne | France | 133 | Sunk | |
15 March 1917 | Eugene Robert | France | 98 | Sunk | |
15 March 1917 | Fleur D’Esperance | France | 24 | Sunk | |
15 March 1917 | Frimaire | United Kingdom | 1,778 | Sunk | |
15 March 1917 | Petit Jean | France | 21 | Sunk | |
16 March 1917 | Anais | France | 130 | Sunk | |
16 March 1917 | Madeleine Davoust | France | 148 | Sunk | |
16 March 1917 | Ronald | Norway | 3,021 | Sunk | |
18 March 1917 | Illinois | United States | 5,225 | Sunk | |
17 April 1917 | HMHS Donegal | 1,885 | Sunk | ||
19 April 1917 | Cilurnum | United Kingdom | 3,126 | Sunk | |
20 April 1917 | Georgios | Greece | 3,124 | Sunk | |
21 April 1917 | Emile Et Charlotte | France | 41 | Sunk | |
21 April 1917 | Ville De Dieppe | Norway | 1,254 | Sunk | |
22 April 1917 | Capenor | United Kingdom | 2,536 | Sunk | |
22 April 1917 | Percy Birdsall | United States | 1,127 | Sunk | |
22 April 1917 | Valerie | Norway | 2,140 | Sunk | |
24 April 1917 | Barnton | United Kingdom | 1,858 | Sunk | |
25 April 1917 | Baigorry | France | 2,161 | Sunk | |
26 April 1917 | Boy Denis | United Kingdom | 41 | Sunk | |
22 May 1917 | Jeune Albert | France | 25 | Sunk | |
23 May 1917 | Harwood Palmer | United States | 2,885 | Sunk | |
23 May 1917 | Lesto | United Kingdom | 1,940 | Sunk | |
26 May 1917 | Aristides | Greece | 2,179 | Sunk | |
26 May 1917 | Norhaug | Norway | 1,245 | Sunk | |
27 May 1917 | Efstathios | Greece | 3,847 | Sunk | |
28 May 1917 | Hiram | Norway | 598 | Sunk | |
28 May 1917 | Urna | Norway | 2,686 | Sunk | |
28 May 1917 | Waldemar | Norway | 1,267 | Sunk | |
30 May 1917 | Sørland | Norway | 2,472 | Sunk | |
2 June 1917 | Tonawanda | United Kingdom | 3,421 | Damaged | |
7 June 1917 | Hafnia | Denmark | 1,619 | Sunk | |
29 June 1917 | Lauwerzee | Netherlands | 47 | Sunk | |
4 July 1917 | Bestevaer | Netherlands | 1,044 | Sunk | |
4 July 1917 | Roelfina | Netherlands | 148 | Captured as prize | |
11 July 1917 | Coquimbo | France | 1,759 | Sunk | |
15 August 1917 | Phoebe | France | 3,956 | Sunk | |
17 August 1917 | Pontoporos | Greece | 4,049 | Sunk | |
19 August 1917 | Therese & Marie | France | 1,615 | Sunk | |
31 August 1917 | Marques De Mudela | Spain | 1,930 | Sunk | |
16 September 1917 | Ann J. Trainer | United States | 426 | Sunk | |
23 September 1917 | St. Dunstan | United Kingdom | 730 | Sunk |