 Wreckage of theUB-46 | |
| History | |
|---|---|
 German Empire | |
| Name | UB-46 |
| Ordered | 31 July 1915[1] |
| Builder | AG Weser,Bremen[1] |
| Yard number | 248[1] |
| Laid down | 4 September 1915[1] |
| Launched | 31 May 1916[1] |
| Commissioned | 12 June 1916[1] |
| Fate | Mined, 7 December 1916 |
| Notes | Torpedo room and battery compartment recovered and preserved |
| General characteristics[2] | |
| Class & type | Type UB II submarine |
| Displacement | |
| Length |
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| Beam |
|
| Draught | 3.68 m (12 ft 1 in) |
| Propulsion |
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| Speed |
|
| Range |
|
| Complement | 22 |
| Armament |
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| Service record | |
| Part of: |
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| Commanders: |
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| Operations: | 5 patrols |
| Victories: | 4 merchant ships sunk (8,099 GRT)[1] |
SMUB-46 was aType UB IIsubmarine orU-boat for theGerman Imperial Navy (German:Kaiserliche Marine) duringWorld War I.UB-46 operated in theMediterranean and theBlack Seas, and was sunk by amine in December 1916.
UB-46 was ordered in July 1915 and waslaid down at theAG Weser shipyard inBremen in September.UB-46 was a little more than 121 feet (37 m) in length anddisplaced between 270 and 305 tonnes (266 and 300 long tons), depending on whether surfaced or submerged. She was equipped to carry a complement of four torpedoes for her two bowtorpedo tubes and had an 5-centimeter (2.0 in)deck gun. As part of a group of six submarines selected for Mediterranean service,UB-46 was broken into railcar sized components and shipped toPola where she was assembled and launched in May 1916, andcommissioned in June.
In early December 1916, during the submarine's fifth patrol,UB-46 struck a mine in the Black Sea a short distance from the north entrance to theBosphorus and sank with all hands. In her six-month career,UB-46 sank four ships of 8,099 gross register tons (GRT).
TheGerman UB II design improved upon the design of theUB I boats, which had been ordered in September 1914.[3] In service, the UB I boats were found to be too small and too slow. A major problem was that, because they had a singlepropeller shaft/engine combo, if either component failed, the U-boat became almost totally disabled.[4] To rectify this flaw, the UB II boats featured twin propeller shafts and twin engines (one shaft for each engine), which also increased the U-boat's top speed.[5] The new design also included more powerful batteries,[4] largertorpedo tubes, and adeck gun.[6] As a UB II boat,U-47 could also carry twice the torpedo load of her UB I counterparts, and nearly ten times as much fuel.[6] To contain all of these changes thehull was larger,[4] and the surface and submergeddisplacement was more than double that of the UB I boats.[6]
The Imperial German Navy orderedUB-46 fromAG Weser on 31 July 1915 as one of a series of six UB II boats (numbered fromUB-42 toUB-47).[6]UB-46 was 36.90 metres (121 ft 1 in) long and 4.37 metres (14 ft 4 in)abeam. She had asingle hull withsaddle tanks and had adraught of 3.68 metres (12 ft 1 in) when surfaced. She displaced 305 tonnes (300 long tons) while submerged but only 272 tonnes (268 long tons) on the surface.[2]
The submarine was equipped with twinDaimlerdiesel engines and twinSiemens-Schuckertelectric motors—for surfaced and submerged running, respectively.UB-46 had a surface speed of up to 8.82 knots (16.33 km/h; 10.15 mph) and could go as fast as 6.22 knots (11.52 km/h; 7.16 mph) while underwater.[6] The U-boat could carry up to 27 tonnes (27 long tons) of diesel fuel, giving her a range of 6,940 nautical miles (12,850 km; 7,990 mi)at 5 knots (9.3 km/h; 5.8 mph). Her electric motors and batteries provided a range of 45 nautical miles (83 km; 52 mi)at 4 knots (7.4 km/h; 4.6 mph) while submerged.[2]
UB-46 was equipped with two 50-centimeter (19.7 in) bowtorpedo tubes and could carry fourtorpedoes. The U-boat was also armed with one8.8 cm (3.5 in) Uk L/30deck gun.[2]
UB-46 was laid down by AG Weser at itsBremen shipyard on 4 September 1915.[1] As one of six U-boats selected for service in the Mediterranean while under construction,UB-46 was broken into railcar-sized components and shipped overland to the Austro-Hungarian port ofPola.[7][8] Shipyard workers from Weser assembled the boat and her five sisters at Pola,[7] where she was launched on 17 June.[1]
SMUB-46 was commissioned into the German Imperial Navy on 12 June 1916 under the command ofOberleutnant zur See Cäsar Bauer.[1][Note 1]UB-46, Bauer's third U-boat command,[9] was assigned to the Navy'sPola Flotilla (German:Deutsche U-Halbflotille Pola).[1] Although the flotilla was based in Pola, the site of the mainAustro-Hungarian Navy base, boats of the flotilla operated out of the Austro-Hungarian base atCattaro which was located farther south and closer to the Mediterranean. German U-boats typically returned to Pola only for repairs.[10] After a month at the helm ofUB-46, Bauer was promoted toKapitänleutnant.[9]
On 2 August, Bauer achieved his first success in command ofUB-46 when the Japanese steamerKohina Maru was sunk offAlexandria just short of her destination ofPort Said.[11] A week later the U-boat sank the Greek sailing vesselBasileios which was headed back to theAdriatic from Egypt.[12] On 2 October, Bauer torpedoedHuntsfall which was carrying hay toSalonica, and took the ship'smaster prisoner.[13] The 4,331 gross register tons (GRT) British steamer was the largest ship sunk byUB-46.[14]
After Germany's conquest of Romania (seeRomania during World War I), the German Imperial Navy had sufficientfuel oil for submarines located in theBlack Sea.UB-46 and three of her sister ships in the Pola Flotilla were ordered to Constantinople and, en route, had to navigate through theDardanelles, which had been heavilymined by theAllies in the middle of 1916.[15][Note 2]UB-46 joined theConstantinople Flotilla (German:U-boote der Mittelmeerdivision in Konstantinopal) on 7 October.[1]
The German submarines in the Black Sea accomplished little, sinking only six ships between August and the end of the year.[16]UB-46 sank one of the six ships when she sent down the 116 GRT Russian shipMelanie north ofCape Tarkhan on 7 November.[17]Melanie was the last ship sunk byUB-46.[14] By early December,UB-46 was based out ofVarna, Bulgaria.[18]
On 7 December 1916, the stern ofUB-46 struck a Russian mine 300 metres (980 ft) off the shore of the Turkish village of Akpınar, approximately 30 kilometres (19 mi) north-west of the entrance to theBosphorus.[19] The vessel's entire complement (reported by Helgason as 20) perished in the sinking.[1][18]
A 16 metres (52 ft) portion of the wreck comprising the forward section of the torpedo room and battery compartment was located in 1993 during coal extraction operations and was salvaged by the Turkish navy; the remainder of the vessel could not be located.[19] She was put on display in an outdoor exhibit at the Turkish Naval Museum in Istanbul.[20] The wreckage was transferred to the Dardanelles Naval Museum atÇanakkale in 2008, where the remains of the vessel are currently on display.[21]
| Date | Name | Nationality | Tonnage[Note 3] | Fate |
|---|---|---|---|---|
| 2 August 1916 | Kohina Maru |  Japan | 3,164 | Sunk |
| 9 August 1916 | Basileios |  Greece | 488 | Sunk |
| 2 October 1916 | Huntsfall |  United Kingdom | 4,331 | Sunk |
| 7 November 1916 | Melanie |  Russian Empire | 116 | Sunk |
| Total: | 8,099 |
Shipwrecks and maritime incidents in December 1916 | |
|---|---|
| Shipwrecks | |
| Other incidents |
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