U-1 class submarine (Austria-Hungary)

The U-1 class was a class

Ship class

A ship class is a group of ships of a similar design. This is distinct from a ship-type, which might reflect a similarity of tonnage or intended use. For example, the is a nuclear aircraft carrier of the Nimitz class....

of two 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...

s or U-boats 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....

. The U-1-class boats were built to an American design 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,...

. The class was a part of the Austro-Hungarian Navy's efforts to competitively evaluate three foreign submarine designs.

The two U-1-class boats, both launched in 1909, were 100 feet (30.5 m) long and as built were each powered by two gasoline engines while surfaced, 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. Neither boat was operational at the beginning 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...

because both were 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 for their problematic gasoline engines.

Beginning in 1915, both boats conducted reconnaissance cruises out of either 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...

or Pola until declared obsolete in early 1918. Both remained in service as a training boats at the submarine base on Brioni, but each was at Pola at the end of the war. They were ceded to Italy as war reparations

War reparations

War reparations are payments intended to cover damage or injury during a war. Generally, the term war reparations refers to money or goods changing hands, rather than such property transfers as the annexation of land.- History :...

in 1920 and scrapped at Pola. Neither submarine sank any ships during the war.

Design and construction

In 1904, after allowing the navies of other countries to pioneer submarine developments, 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....

ordered the Austrian Naval Technical Committee (MTK) to produce a submarine design. The January 1905 design developed by the MTK and other designs submitted by the public as part of a design competition were all rejected by the Navy as impracticable. They instead opted to order two submarines each of designs by 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...

for a competitive evaluation. The two Lake-designed submarines comprised the U-1 class.The Germaniawerft design became the U-3-class

U-3 class submarine (Austria-Hungary)

The U-3 class was a class of two submarines or U-boats built for and operated by the Austro-Hungarian Navy . The U-3-class boats were designed and built by Germaniawerft of Kiel, Germany...

while the Holland design became the U-5 class

U-5 class submarine (Austria-Hungary)

The U-5 class was a class of three submarines or U-boats that were operated by the Austro-Hungarian Navy before and during World War I. The class was a part of the Austro-Hungarian Navy's efforts to competitively evaluate three foreign submarine designs....

. The Navy ordered plans for the building of two boats—designated U-1 and U-2—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...

, in 1906.

The U-1-class design 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, in theory, could allow 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. The propulsion system for the U-1 class 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. For underwater steering and maneuverability, the design featured four pairs of diving plane

Diving plane

A diving plane, also known as a hydroplane, is a control surface found on submarines which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when submerged....

s.

The boats were 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, each boat 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...

229.7 metric tons (226.1 LT) surfaced and 248.9 metric tons (245 LT) submerged. Both of the submarines had 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. Each submarine was also armed with a 37 millimetres (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...

.

U-1 and U-2 were laid down in July 1907 at the navy yard at Pola

Pula

, and were launched in February and April 1909, respectively.In their book The German Submarine War, 1914–1918, R. H. Gibson and Maurice Prendergast report that U-1 was launched in 1911 and U-2 in 1910 (p. 383).

Service career

Upon completion of the two boats, the Austro-Hungarian Navy evaluated the U-1 class in trials through 1910. During the trials, technical problems with the gasoline engines were revealed. Exhaust fumes and gasoline vapors frequently poisoned the air inside the boats and the engines themselves were not able reach the contracted speed. Because of the problems, the Austro-Hungarian Navy considered the engines to be unsuitable for wartime use and paid only for the hulls and armament of the two U-1 boats. 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, they agreed to a lease of the gasoline engines at a fee of US$4,544 annually.

In order to dive, the diving tanks, located above the waterline, had to be flooded by pumps, which took over 14½ minutes in early tests, but which was later reduced to 8 minutes. The maximum diving depth was set at 40 metres (131.2 ft) when the hulls began to show signs of stress at that depth. The four pairs of diving planes gave the boats exceptional underwater handling, and, when the boats were properly trimmed and balanced, the boats could be held within 20 centimetres (7.9 in) of the desired depth. Other tests proved the underwater wheels to be useless. The U-1 class boats outperformed the U-3

U-3 class submarine (Austria-Hungary)

The U-3 class was a class of two submarines or U-boats built for and operated by the Austro-Hungarian Navy . The U-3-class boats were designed and built by Germaniawerft of Kiel, Germany...

(Germaniawerft) and U-5

U-5 class submarine (Austria-Hungary)

(Holland) classes in both diving and steering capabilities in the Austro-Hungarian Navy evaluations.

Both boats were officially commissioned into the Austro-Hungarian Navy in 1911—U-1 in April, U-2 in June—and served as training boats, each making as many as ten training cruises a month. At the outbreak of World War I

World War I

, U-1 and U-2 were both in drydock awaiting the installation of their new diesel engines. To accommodate the new engines, the boats were lengthened by about 11 inches (27.9 cm). These changes lowered the surface displacement to 223 metric tons (219.5 LT) but increased the submerged displacement to 277.5 metric tons (273.1 LT).

From 1915, both boats conducted reconnaissance cruises out of either Trieste

Trieste

or Pola. In January 1918, the boats were declared obsolete, but remained in service as training boats at the submarine base at Brioni, but at the war's end both boats were in Pola, After the war, both boats were ceded to Italy as war reparations

War reparations

and scrapped. Neither boat sank any ships during the war.

SM U-1

U-1 was laid down at the navy yard at Pola

Pula

in July 1907, launched in February 1909, and underwent trials throughout 1910. She was commissioned in April 1911 and served as a training boat through 1914. Her periscope

Periscope

A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....

was damaged when she was accidentally rammed by an Austro-Hungarian cruiser in January 1914. At the beginning of World War I, U-1 was not operational because she was in drydock awaiting new batteries and 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. When the engine swap had been completed, U-1 served as a training boat for the Austro-Hungarian Navy through October 1915. From November that same year she conducted reconnaissance cruises out of Trieste

Trieste

and Pola until she was declared obsolete in early 1918. U-1 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 awarded to Italy as a war reparation in 1920 and scrapped at Pola. U-1 did not sink any ships during the war.

SM U-2

SM U-2 was laid down at the navy yard at Pola in July 1907, launched in April 1909, and underwent trials through 1910. She was commissioned in June 1911 and served as a training boat 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

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 sank no ships during the war.

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