SM U-2 (Austria-Hungary)
Encyclopedia
SM U-2 or U-II was a U-1-class
U-1 class submarine (Austria-Hungary)
The U-1 class was a class of two submarines or U-boats built for and operated by the Austro-Hungarian Navy . The U-1-class boats were built to an American design at the navy yard in Pola...
submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
or U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...
built for and operated by the Austro-Hungarian Navy
Austro-Hungarian Navy
The Austro-Hungarian Navy was the naval force of Austria-Hungary. Its official name in German was Kaiserliche und Königliche Kriegsmarine , abbreviated as k.u.k. Kriegsmarine....
. U-2 was designed by American Simon Lake
Simon Lake
Simon Lake was a Quaker American mechanical engineer and naval architect who obtained over two hundred patents for advances in naval design and competed with John Philip Holland to build the first submarines for the United States Navy.Born in Pleasantville, New Jersey, Lake joined his father's...
's Lake Torpedo Boat Company and built at the navy yard in Pola
Pula
Pula is the largest city in Istria County, Croatia, situated at the southern tip of the Istria peninsula, with a population of 62,080 .Like the rest of the region, it is known for its mild climate, smooth sea, and unspoiled nature. The city has a long tradition of winemaking, fishing,...
. She was one of two Lake-designed submarines purchased as part of a competitive evaluation of three foreign submarine designs.
U-2 was launched in April 1909 and was 100 feet (30.5 m) long and displaced
Displacement (ship)
A ship's displacement is its weight at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's weight when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load...
almost 230 tonnes (253.5 ST) surfaced and just under 249 tonnes (274.5 ST) when submerged. The Austro-Hungarian Navy conducted trials for U-2 through 1910. The U-boat was originally powered by two gasoline engines for surface running, and two electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
s when submerged, but during her evaluation period, the gasoline engines were found to be incapable of reaching the contracted speed. U-2 was commissioned in June 1911 and served as a training boat for the Austro-Hungarian Navy through 1914.
At the beginning of World War I, U-2 was not operational because she was in drydock awaiting replacement diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s. With her new engines and a new conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....
installed by June 1915, U-2 conducted reconnaissance cruises out of Trieste
Trieste
Trieste is a city and seaport in northeastern Italy. It is situated towards the end of a narrow strip of land lying between the Adriatic Sea and Italy's border with Slovenia, which lies almost immediately south and east of the city...
but was declared obsolete in early 1918. U-2 remained in service as a training boat at the submarine base on Brioni, but was at Pola at the end of the war. She was ceded to Italy as a war reparation in 1920 and scrapped at Pola. U-2 did not sink any ships during the war.
Design and construction
U-2 was built as part of a plan by the Austro-Hungarian NavyAustro-Hungarian Navy
The Austro-Hungarian Navy was the naval force of Austria-Hungary. Its official name in German was Kaiserliche und Königliche Kriegsmarine , abbreviated as k.u.k. Kriegsmarine....
to competitively evaluate foreign submarine designs from Simon Lake
Simon Lake
Simon Lake was a Quaker American mechanical engineer and naval architect who obtained over two hundred patents for advances in naval design and competed with John Philip Holland to build the first submarines for the United States Navy.Born in Pleasantville, New Jersey, Lake joined his father's...
, Germaniawerft
Friedrich Krupp Germaniawerft
Friedrich Krupp Germaniawerft was a German shipbuilding company, located in the harbour at Kiel, and one of the largest and most important builders of U-boats for the Kaiserliche Marine in World War I and the Kriegsmarine in World War II.-History:The company was founded in 1867 by Lloyd Foster, as...
, and John Philip Holland
John Philip Holland
John Philip Holland was an Irish engineer who developed the first submarine to be formally commissioned by the U.S...
. The Austro-Hungarian Navy ordered plans for U-2 (and sister ship U-1) in 1906 from the Lake Torpedo Boat Company of Bridgeport, Connecticut
Bridgeport, Connecticut
Bridgeport is the most populous city in the U.S. state of Connecticut. Located in Fairfield County, the city had an estimated population of 144,229 at the 2010 United States Census and is the core of the Greater Bridgeport area...
. U-2 was built at the Pola Navy Yard and was launched on 3 April 1909.In their book The German Submarine War, 1914–1918, R. H. Gibson and Maurice Prendergast report that U-2 was launched in 1910 (p. 383).
U-2 had several features typical of Lake's designs, including a diving chamber under the bow and two variable pitch propellers. Lake's design also called for two retractable wheels that allowed travel over the seabed
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
. The design also placed the diving tanks above the waterline of the single, cylindrical hull
Submarine hull
The term light hull is used to describe the outer hull of a submarine, which houses the pressure hull, providing hydrodynamically efficient shape, but not holding pressure difference...
, which necessitated a heavy ballast keel
Keel
In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...
for vertical stability. This arrangement required mechanical pumping, a procedure that took 8 minutes. U-2s propulsion system consisted of two gasoline engines for surface running and two electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
s for running while submerged.
The boat was 100 feet (30 m) long by 15 in 9 in (4.8 m) abeam and had a draft of 12 in 8 in (3.86 m). As designed, her displacement
Displacement (ship)
A ship's displacement is its weight at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's weight when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load...
was 229.7 long tons (233.4 t) surfaced and 248.9 long tons (252.9 t) submerged. She was outfitted with three 45 centimetres (17.7 in) torpedo tubes—two in the bow, one in the stern—and could carry up to five torpedoes, but typically carried three. U-2 was also armed with a 3.7 centimetres (1.5 in) deck gun
Deck gun
A deck gun is a type of artillery cannon mounted on the deck of a ship or submarine.The deck gun was used as a defensive weapon against smaller boats or ships and in certain cases where torpedo use was limited. Typically a crew of three; gunner, loader, and layer, operated the gun, while others...
.
Service career
Upon U-2s completion, the Austro-Hungarian NavyAustro-Hungarian Navy
The Austro-Hungarian Navy was the naval force of Austria-Hungary. Its official name in German was Kaiserliche und Königliche Kriegsmarine , abbreviated as k.u.k. Kriegsmarine....
conducted trials of the submarine throughout most of 1910. U-2s gasoline engines were never able to meet the speed called for in the contract during the Navy evaluations,Sister ship s engines were equally inadequate. and were considered not suitable for wartime use. As a result, the Navy only paid for U-2s hull and armament, and arranged a lease of the gasoline engines while replacement diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s were ordered from the Austrian firm Maschinenfabrik Leobersdorf. Despite the engine problems, U-2 and her sister ship had the best performance in diving and steering amongst the U-boats under evaluation by the Navy.
U-2 was commissioned into the Austro-Hungarian Navy on 22 June 1911 under the command of Linienschiffsleutnant Klemens Ritter von Bézard. U-2 served as a training boat through 1915, conducting up to ten training cruises per month. At the outbreak of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, she was in drydock awaiting the installation of her new diesel engines. To accommodate the new engines, she was lengthened by about 11 inches (27.9 cm). The modifications and new engines lowered her surface displacement to 223 tonnes (245.8 ST) but increased her submerged displacement to 277.5 tonnes (305.9 ST).
From January to June 1915, U-2 underwent a refit and received a new conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....
. She was stationed at Trieste
Trieste
Trieste is a city and seaport in northeastern Italy. It is situated towards the end of a narrow strip of land lying between the Adriatic Sea and Italy's border with Slovenia, which lies almost immediately south and east of the city...
in mid July and conducted reconnaissance cruises from that port. On 11 January 1918, she was declared obsolete, but was retained as a training boat at the submarine base on Brioni. U-2 was at Pola at the war's end, and was scrapped after her cession to Italy as a war reparation in 1920. U-2 did not sink any ships during the war.