|Ordered:||25 January 1939|
|Builder:||Bremer Vulkan, Bremen-Vegesack|
|Laid down:||28 March 1940|
|Launched:||7 December 1940|
|Commissioned:||15 February 1941|
|Fate:||Sunk on 16 April 1945 by Soviet artillery fire.|
|Class and type:||Type VIIC submarine|
|Height:||9.60 m (31 ft 6 in)|
|Draught:||4.74 m (15 ft 7 in)|
|Complement:||4 officers, 40–56 enlisted|
German submarine U-78 was a Type VIIC submarine of Nazi Germany's Kriegsmarine during World War II. She was the only German submarine to be sunk by land-based artillery fire during the war. Built by Bremen-Vegesack.
She was ordered on 25 January 1939, and laid down on 28 March 1940, in the shipyard of Bremer Vulkan in the port city of Bremen-Vegesack as yard number 6. U-78 was launched on 7 December 1940 and formally commissioned into the Kriegsmarine as a "school boat" on 15 February 1941, with a crew of 41 under the command of Kapitänleutnant Alfred Dumrese.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-78 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two MAN M 6 V 40/46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-78 was fitted with two 53.3 cm (21 in) torpedo tubes at the bow, fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
U-78 spent the majority of her career as a training U-boat, during which time she had several different crews. As a result, she never sank any enemy vessels nor engaged any enemy ships or convoys. On 1 March 1945, she was transferred to the 4th U-boat Flotilla but never saw any combat; prior to beginning her first patrol she was sunk on 16 April 1945. U-78's fate is notable in that she was the only German U-boat to be sunk by land-based artillery fire during World War II.
U-78 spent almost her entire career as part of the 22nd U-boat Flotilla as a "school boat", a role which saw her being used to train U-boat crews. During this time, her commander was changed six times: in July 1941 from Kapitänleutnant (Kptlt.) Alfred Dumrese to Oberleutnant zur See (O/L) Kurt Makowski, who remained in command until February 1942 when she was handed over to Kptlt. Max Bernd Dieterich; in July 1942, Kptlt. Ernst Ziehm took command of the U-boat from Dieterich in November 1942. Kptlt. Helmut Sommer took command from Ziehm in May 1943; the sixth commander of U-78 took control of the U-boat when Wilhelm Eisele was named captain and lastly, the seventh commander, O/L Horst Hübsch, took command of U-78 from Eisele on 27 November 1944. All of U-78's changes of command took place while the U-boat was still serving as a training boat. Crewmembers used her as a practice submarine before being assigned to their operational U-boat.
By March 1945, the war was coming to an end, the Kriegsmarine was faced with a dwindling number of active U-boats. To offset this, the Navy looked to transfer boats away from other duties, such as training. On 1 March 1945, U-78 began active service with the 4th U-boat Flotilla. Just a month and a half later, however, on 16 April 1945, U-78 was sunk after being attacked by Soviet land-based artillery while she was docked near the electricity supply pier in the German port of Pillau in East Prussia.