SM UB-125

For other ships with the same name, see German submarine U-125.

UB-148 at sea, a U-boat similar to UB-125.
History
German Empire
Name	UB-125
Ordered	6 / 8 February 1917 [1]
Builder	AG Weser, Bremen
Cost	3,654,000 German Papiermark
Yard number	298
Laid down	19 July 1917 [2]
Launched	16 April 1918 [3]
Commissioned	18 May 1918 [3]
Fate	Surrendered 20 November 1918 [3]
Japan
Name	O-6
Commissioned	1920 [3]
Decommissioned	1921 [3]
Fate	Broken up in Kure [3]
General characteristics [3]
Class and type	Type UB III submarine
Displacement	512  t (504 long tons) surfaced 643 t (633 long tons) submerged
Length	55.85 m (183 ft 3 in) (o/a)
Beam	5.80 m (19 ft)
Draught	3.72 m (12 ft 2 in)
Propulsion	2 × propeller shaft 2 × Körting four-stroke 6-cylinder diesel engines, 1,050  bhp (780 kW) 2 × Siemens-Schuckert electric motors, 780  shp (580 kW)
Speed	13.9 knots (25.7 km/h; 16.0 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	7,280  nmi (13,480 km; 8,380 mi) at 6 knots (11 km/h; 6.9 mph) surfaced 55 nmi (102 km; 63 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	50 m (160 ft)
Complement	3 officers, 31 men [3]
Armament	5 × 50 cm (19.7 in) torpedo tubes (4 bow, 1 stern) 10 torpedoes 1 × 10.5 cm (4.13 in) deck gun
Service record
Part of:	III Flotilla 21 July – 11 November 1918
Commanders:	Kptlt. Fritz Schubert [4] 18 May – 20 July 1918 Oblt.z.S. Werner Vater [5] 21 July – 11 November 1918
Operations:	2 patrols
Victories:	6 merchant ships sunk (13,307  GRT) 1 merchant ship damaged (6,082  GRT)

SM UB-125 was a German Type UB III submarine or U-boat in the German Imperial Navy (German : Kaiserliche Marine) during World War I. She was commissioned into the German Imperial Navy on 18 May 1918 as SM UB-125. ^{[Note 1]}

UB-125 was surrendered 20 November 1918 in accordance with the requirements of the Armistice with Germany. Handed over to Japan, she served as O-6 in the Imperial Japanese Navy until 1921 when she was broken up in Kure. ^[3]

Construction

Main article: Type UB III submarine

She was built by AG Weser of Bremen and following just under a year of construction, launched at Bremen on 16 April 1918. UB-125 was commissioned later the same year under the command of Kptlt. Fritz Schubert. Like all Type UB III submarines, UB-125 carried 10 torpedoes and was armed with a 10.5 cm (4.13 in) deck gun. UB-125 would carry a crew of up to 3 officer and 31 men and had a cruising range of 7,280 nautical miles (13,480 km; 8,380 mi). UB-125 had a displacement of 512  t (504 long tons) while surfaced and 643 t (633 long tons) when submerged. Her engines enabled her to travel at 13.9 knots (25.7 km/h; 16.0 mph) when surfaced and 7.6 knots (14.1 km/h; 8.7 mph) when submerged.

Summary of raiding history

Date	Name	Nationality	Tonnage [Note 2]	Fate [6]
29 August 1918	Atxeri Mendi	Spain	2,424	Sunk
30 August 1918	Onega	United States	3,636	Sunk
1 September 1918	Actor	United Kingdom	6,082	Damaged
3 September 1918	Brava	Portugal	3,184	Sunk
3 September 1918	Lake Owens	United States	2,308	Sunk
4 September 1918	Bogstad	Norway	1,589	Sunk
12 September 1918	Skjold	Denmark	166	Sunk

References

Notes

1. "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
2. Tonnages are in gross register tons

Citations

1. Rössler 1979, p. 55.
2. Helgason, Guðmundur. "WWI U-boats: UB 125". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 13 February 2009.
3. Gröner 1991, pp. 25–30.
4. Helgason, Guðmundur. "WWI U-boat commanders: Fritz Schubert". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 11 March 2015.
5. Helgason, Guðmundur. "WWI U-boat commanders: Werner Vater". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 11 March 2015.
6. Helgason, Guðmundur. "Ships hit by UB 125". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 11 March 2015.

Bibliography

• Bendert, Harald (2000). Die UB-Boote der Kaiserlichen Marine, 1914-1918. Einsätze, Erfolge, Schicksal (in German). Hamburg: Verlag E.S. Mittler & Sohn GmbH. ISBN   3-8132-0713-7.
• Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN   0-85177-593-4.
• Rössler, Eberhard (1979). Die deutschen U-Boote und ihre Werften: eine Bilddokumentation über den deutschen U-Bootbau; in zwei Bänden (in German). Vol. I. Munich: Bernard & Graefe. ISBN   3-7637-5213-7.