World War II
World War II known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries; the major participants threw their entire economic and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China, it included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, the only use of nuclear weapons in war. Japan, which aimed to dominate Asia and the Pacific, was at war with China by 1937, though neither side had declared war on the other. World War II is said to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom.
From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. Following the onset of campaigns in North Africa and East Africa, the fall of France in mid 1940, the war continued between the European Axis powers and the British Empire. War in the Balkans, the aerial Battle of Britain, the Blitz, the long Battle of the Atlantic followed. On 22 June 1941, the European Axis powers launched an invasion of the Soviet Union, opening the largest land theatre of war in history; this Eastern Front trapped most crucially the German Wehrmacht, into a war of attrition. In December 1941, Japan launched a surprise attack on the United States as well as European colonies in the Pacific. Following an immediate U. S. declaration of war against Japan, supported by one from Great Britain, the European Axis powers declared war on the U.
S. in solidarity with their Japanese ally. Rapid Japanese conquests over much of the Western Pacific ensued, perceived by many in Asia as liberation from Western dominance and resulting in the support of several armies from defeated territories; the Axis advance in the Pacific halted in 1942. Key setbacks in 1943, which included a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, Allied victories in the Pacific, cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned toward Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in Central China, South China and Burma, while the Allies crippled the Japanese Navy and captured key Western Pacific islands; the war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the German unconditional surrender on 8 May 1945.
Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings, the Soviet entry into the war against Japan and its invasion of Manchuria, Japan announced its intention to surrender on 15 August 1945, cementing total victory in Asia for the Allies. Tribunals were set up by fiat by the Allies and war crimes trials were conducted in the wake of the war both against the Germans and the Japanese. World War II changed the political social structure of the globe; the United Nations was established to foster international co-operation and prevent future conflicts. The Soviet Union and United States emerged as rival superpowers, setting the stage for the nearly half-century long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia.
Most countries whose industries had been damaged moved towards economic expansion. Political integration in Europe, emerged as an effort to end pre-war enmities and create a common identity; the start of the war in Europe is held to be 1 September 1939, beginning with the German invasion of Poland. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred and the two wars merged in 1941; this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935; the British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the fo
Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels. Two types of technology share the name "sonar": passive sonar is listening for the sound made by vessels. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may be used in air for robot navigation, SODAR is used for atmospheric investigations; the term sonar is used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from low to high; the study of underwater sound is known as underwater hydroacoustics. The first recorded use of the technique was by Leonardo da Vinci in 1490 who used a tube inserted into the water to detect vessels by ear, it was developed during World War I to counter the growing threat of submarine warfare, with an operational passive sonar system in use by 1918.
Modern active sonar systems use an acoustic transponder to generate a sound wave, reflected back from target objects. Although some animals have used sound for communication and object detection for millions of years, use by humans in the water is recorded by Leonardo da Vinci in 1490: a tube inserted into the water was said to be used to detect vessels by placing an ear to the tube. In the late 19th century an underwater bell was used as an ancillary to lighthouses or light ships to provide warning of hazards; the use of sound to "echo-locate" underwater in the same way as bats use sound for aerial navigation seems to have been prompted by the Titanic disaster of 1912. The world's first patent for an underwater echo-ranging device was filed at the British Patent Office by English meteorologist Lewis Fry Richardson a month after the sinking of the Titanic, a German physicist Alexander Behm obtained a patent for an echo sounder in 1913; the Canadian engineer Reginald Fessenden, while working for the Submarine Signal Company in Boston, built an experimental system beginning in 1912, a system tested in Boston Harbor, in 1914 from the U.
S. Revenue Cutter Miami on the Grand Banks off Newfoundland. In that test, Fessenden echo ranging; the "Fessenden oscillator", operated at about 500 Hz frequency, was unable to determine the bearing of the iceberg due to the 3-metre wavelength and the small dimension of the transducer's radiating face. The ten Montreal-built British H-class submarines launched in 1915 were equipped with Fessenden oscillators. During World War I the need to detect; the British made early use of underwater listening devices called hydrophones, while the French physicist Paul Langevin, working with a Russian immigrant electrical engineer Constantin Chilowsky, worked on the development of active sound devices for detecting submarines in 1915. Although piezoelectric and magnetostrictive transducers superseded the electrostatic transducers they used, this work influenced future designs. Lightweight sound-sensitive plastic film and fibre optics have been used for hydrophones, while Terfenol-D and PMN have been developed for projectors.
In 1916, under the British Board of Invention and Research, Canadian physicist Robert William Boyle took on the active sound detection project with A. B. Wood, producing a prototype for testing in mid-1917; this work, for the Anti-Submarine Division of the British Naval Staff, was undertaken in utmost secrecy, used quartz piezoelectric crystals to produce the world's first practical underwater active sound detection apparatus. To maintain secrecy, no mention of sound experimentation or quartz was made – the word used to describe the early work was changed to "ASD"ics, the quartz material to "ASD"ivite: "ASD" for "Anti-Submarine Division", hence the British acronym ASDIC. In 1939, in response to a question from the Oxford English Dictionary, the Admiralty made up the story that it stood for "Allied Submarine Detection Investigation Committee", this is still believed, though no committee bearing this name has been found in the Admiralty archives. By 1918, Britain and France had built prototype active systems.
The British tested their ASDIC on HMS Antrim in 1920 and started production in 1922. The 6th Destroyer Flotilla had ASDIC-equipped vessels in 1923. An anti-submarine school HMS Osprey and a training flotilla of four vessels were established on Portland in 1924; the U. S. Sonar QB set arrived in 1931. By the outbreak of World War II, the Royal Navy had five sets for different surface ship classes, others for submarines, incorporated into a complete anti-submarine attack system; the effectiveness of early ASDIC was hampered by the use of the depth charge as an anti-submarine weapon. This required an attacking vessel to pass over a submerged contact before dropping charges over the stern, resulting in a loss of ASDIC contact in the moments leading up to attack; the hunter was firing blind, during which time a submarine commander could take evasive action. This situation was remedied by using several ships cooperating and by the adoption of "ahead-throwing weapons", such as Hedgehogs and Squids, which proj
The French Navy, informally "La Royale", is the maritime arm of the French Armed Forces. Dating back to 1624, the French Navy is one of the world's oldest naval forces, it has participated in conflicts around the globe and played a key part in establishing the French colonial empire. The French Navy consists of six main branches and various services: the Force d'Action Navale, the Forces Sous-marines, the Maritime Force of Naval Aeronautics, the Fusiliers Marins, the Marins Pompiers, the Maritime Gendarmerie; as of June 2014, the French Navy employed a total of 36,776 personnel along with 2,800 civilians. Its reserve element consisted of 4,827 personnel of the Operational Reserve; as a blue-water navy, it operates a wide range of fighting vessels, which include the nuclear-powered aircraft carrier Charles de Gaulle, various aeronaval forces, attack submarines and ballistic missile submarines, patrol boats and support ships. The history of French naval power dates back to the Middle Ages, had three loci of evolution: The Mediterranean Sea, where the Ordre de Saint-Jean de Jérusalem had its own navy, the Levant Fleet, whose principal ports were Fréjus and Toulon.
The Ordre, both a religious and military order, recruited knights from the families of French nobility. Members who had fulfilled their service at sea were granted the rank of Knights Hospitaller, elites who served as the officer corps; the Ordre was one of the ancestors of modern French naval schools including the French Naval Academy. The Manche along Normandy which, since William the Conqueror, always tendered capable marines and sailors from its numerous active seaports; the first true French Royal Navy was established in 1624 by Cardinal Richelieu, chief minister to King Louis XIII. During the French Revolution, la Marine Royale was formally renamed la Marine Nationale. Under the First French Empire and the Second French Empire, the navy was designated as the Imperial French Navy. Institutionally, the navy has never lost its short familiar nickname, la Royale; the symbol of the French Navy was since its origin a golden anchor, beginning in 1830, was interlaced by a sailing rope. This symbol was featured on all naval vessels and uniforms.
Although anchor symbols are still used on uniforms, a new naval logo was introduced in 1990. Authorized by Naval Chief of Staff Bernard Louzeau, the modern design incorporates the tricolour by flanking the bow section of a white warship with two ascending red and blue spray foams, the inscription "Marine nationale". Cardinal Richelieu supervised the Navy until his death in 1643, he was succeeded by his protégé, Jean Baptiste Colbert, who introduced the first code of regulations of the French Navy, established the original naval dockyards in Brest and Toulon. Colbert and his son, the Marquis de Seignelay, between them administered the Navy for twenty-nine years. During this century, the Navy cut its teeth in the Anglo-French War, the Franco-Spanish War, the Second Anglo-Dutch War, the Franco-Dutch War, the Nine Years' War. Major battles in these years include the Battle of Beachy Head, the Battles of Barfleur and La Hougue, the Battle of Lagos, the Battle of Texel; the 1700s opened with the War of the Spanish Succession, over a decade long, followed by the War of the Austrian Succession in the 1740s.
Principal engagements of these wars include the Battle of Vigo Bay and two separate Battles of Cape Finisterre in 1747. The most grueling conflict for the Navy, was the Seven Years' War, in which it was destroyed. Significant actions include the Battle of Cap-Français, the Battle of Quiberon Bay, another Battle of Cape Finisterre; the Navy regrouped and rebuilt, within 15 years it was eager to join the fray when France intervened in the American Revolutionary War. Though outnumbered everywhere, the French fleets held the British at bay for years until victory. After this conflict and the concomitant Anglo-French War, the Navy emerged at a new height in its history. Major battles in these years include the Battle of the Chesapeake, the Battle of Cape Henry, the Battle of Grenada, the invasion of Dominica, three separate Battles of Ushant. Within less than a decade, the Navy was decimated by the French Revolution when large numbers of veteran officers were dismissed or executed for their noble lineage.
Nonetheless, the Navy fought vigorously through the French Revolutionary Wars as well as the Quasi-War. Significant actions include a fourth Battle of Ushant, the Battle of Groix, the Atlantic campaign of May 1794, the French expedition to Ireland, the Battle of Tory Island, the Battle of the Nile. Other engagements of the Revolutionary Wars ensued in the early 1800s, including the Battle of the Malta Convoy and the Algeciras Campaign; the Quasi-War wound down with single-ship actions including USS Constellation vs La Vengeance and USS Enterprise vs Flambeau. When Napoleon was crowned Emperor in 1804, he attempted to restore the Navy to a position that would enable his plan for an invasion of England, his dreams were dashed by the Battle of Trafalgar in 1805, where the British all but annihilated a combined Franco-Spanish fleet, a disaster that guaranteed British naval superiority throughout the Napoleonic Wars. Still, the Navy did not shrink from action: among the engagements of this time were the Battle of the Basque Roads, the Battle of Grand Port, the Mauritius campaign of 1809–11, the Battle of Lissa, After Nap
Siemens-Schuckert was a German electrical engineering company headquartered in Berlin and Nuremberg, incorporated into the Siemens AG in 1966. Siemens Schuckert was founded in 1903 when Halske acquired Schuckertwerke. Subsequently, Siemens & Halske specialized in communications engineering and Siemens-Schuckert in power engineering and pneumatic instrumentation. During World War I Siemens-Schuckert produced aircraft, it took over manufacturing of the renowned Protos vehicles in 1908. In World War II, the company had a factory producing aircraft and other parts at Monowitz near Auschwitz. There was a workers camp near the factory known as Bobrek concentration camp; the Siemens Schuckert logo consisted of an S with a smaller S superimposed on the middle with the smaller S rotated left by 45 degrees. The logo was used into the late 1960s, when both companies merged with the Siemens-Reiniger-Werke AG to form the present-day Siemens AG. Siemens-Schuckert built a number of designs in inter-war era, they produced aircraft engines under the Siemens-Halske brand, which evolved into their major product line after the end of World War I.
The company reorganized as Brandenburgische Motorenwerke, or Bramo, in 1936, were purchased in 1939 by BMW to become BMW Flugmotorenbau. Siemens-Schuckert designed a number of heavy bombers early in World War I, building a run of seven Riesenflugzeug. Intended to be used in the strategic role in long duration flights, the SSW R-series had three 150 h.p Benz Bz. III engines in the cabin driving two propellers connected to a common gear-box through a combination leather-cone and centrifugal-key clutch in SSW R. I to the SSW R. VII models. In the case of engine failure, common at the time, the bomber could continue flying on two engines while the third was repaired by the in-flight mechanic. Two transmission shafts transferred the power from the gear-box to propeller gear-boxes mounted on the wing struts. Although there were some problems with the clutch system, the gear-box proved to be reliable when properly maintained; the SSW R.1 through the SSW R. VII designs were noted for their distinctive forked fuselage.
Several of these aircraft fought on the Eastern Front. Although interesting in concept, the cost of these and the R-types from other companies was so great that the air force abandoned the concept until more practical designs arrived in the war; the first fighter designed at the works was the Siemens-Schuckert E. I which appeared in mid 1915, was the first aircraft to be powered by the Siemens-Halske Sh. I, a new rotary, developed by Siemens-Schuckert, in which the cylinders and the propeller rotated in opposite directions. A small number of production machines were supplied to various Feldflieger Abteilung to supplement supplies of the Fokker and Pfalz monoplane fighters used at the time for escort work; the prototype SSW E. II, powered by the inline Argus AsII, crashed in June 1916, killing Franz Steffen, one of the designers of the SSW R types. By early 1916 the first generation of German monoplane fighters were outclassed by the Nieuport 11 and the Nieuport 17 which quickly followed it; the resulting SSW D.
I was powered by the Siemens-Halske Sh. I, but was otherwise a literal copy of the Nieuport 17; this aircraft was the first Siemens-Schuckert fighter to be ordered in quantity, but by the time it became available in numbers it was outclassed by contemporary Albatros fighters. Development of the Sh. I 160 hp Sh. III one of the most advanced rotary engine designs of the war; the D. I fighter formed the basis for a series of original designs, which by the end of 1917 had reached a peak in the Siemens-Schuckert D. III, which went into limited production in early 1918, found use in home defense units as an interceptor, due to its outstanding rate of climb. Further modifications improved its handling and performance to produce the Siemens-Schuckert D. IV. Several offshoots of the design included triplanes and a parasol monoplane. With the end of the war production of the D. IV continued for sales to Switzerland who flew them into the late 1920s. With the signing of the Treaty of Versailles the next year all aircraft production in Germany was shut down.
Siemens-Schuckert disappeared, but Siemens-Halske continued sales of the Sh. III and started development of smaller engines for the civilian market. By the mid-1920s their rotary engines were no longer in vogue, but "non-turning" versions of the same basic mechanicals led to a series of 7-cylinder radial engines, the Sh.10 through Sh.14A, delivering up to 150 hp in the 14A. The Sh.14A became a best-seller in the trainer market, over 15,000 of all the versions were built. Siemens-Halske no longer had any competitive engines for the larger end of the market, to address this they negotiated a license in 1929 to produce the 9-cylinder Bristol Jupiter IV. Minor changes for the German market led to the Sh.20 and Sh.21. Following the evolution of their smaller Sh.14's, the engine was bored out to produce the 900 hp design, the Sh.22. In 1933 new engine naming was introduced by the RLM, this design became the Sh.322, when Siemens was given the 300-block of numbers. The Sh.322 design never became popular.
The company reorganized as Bramo in 1936, continued development of what was now their own large engine. Modifying the Sh.322 with the addition of fuel injection and a new supercharger led to the Bramo 323 Fafnir, which entered production in 1937. Although ra
2 cm Flak 30/38/Flakvierling
The Flak 30 and improved Flak 38 were 20 mm anti-aircraft guns used by various German forces throughout World War II. It was not only the primary German light anti-aircraft gun, but by far the most numerously produced German artillery piece throughout the war, it was produced in a variety of models, notably the Flakvierling 38 which combined four Flak 38 autocannons onto a single carriage. The Germans fielded the unrelated early 2 cm Flak 28 just after World War I, but the Treaty of Versailles outlawed these weapons and they were sold to Switzerland; the original Flak 30 design was developed from the Solothurn ST-5 as a project for the Kriegsmarine, which produced the 20 mm C/30. The gun fired the "Long Solothurn", a 20 × 138 mm belted cartridge, developed for the ST-5 and was one of the most powerful 20 mm rounds in existence; the C/30, featuring a barrel length of 65 calibres, had a rate of about 120 rounds per minute. Disappointingly, it proved to have feeding problems and would jam, offset to some degree by its undersized 20 round-magazine which tended to make reloading a frequent necessity.
The C/30 became the primary shipborne light AA weapon and equipped a large variety of German ships. The MG C/30L variant was used experimentally as an aircraft weapon, notably on the Heinkel He 112, where its high power allowed it to penetrate armored cars and the light tanks of the era during the Spanish Civil War. Rheinmetall started an adaptation of the C/30 for Army use, producing the 2 cm Flak 30. Similar to the C/30, the main areas of development were the mount, compact. Set-up could be accomplished by dropping the gun to the ground off its two-wheeled carriage and levelling with hand cranks; the result was a triangular base. But the main problem with the design remained unsolved; the rate of fire of 120 RPM was not fast for a weapon of this calibre. Rheinmetall responded with the 2 cm Flak 38, otherwise similar but increased the rate of fire to 220 RPM and lowered overall weight to 420 kg; the Flak 38 was accepted as the standard Army gun in 1939, by the Kriegsmarine as the C/38. In order to provide airborne and mountain troops with AA capabilities, Mauser was contracted to produce a lighter version of the Flak 38, which they introduced as the 2 cm Gebirgsflak 38.
It featured a simplified mount using a tripod that raised the entire gun off the ground, which had the side benefit of allowing it to be set up on an uneven surface. These changes reduced the overall weight of the gun to a mere 276.0 kg. Production started in 1941 and entered service in 1942. A wide variety of 20x138B ammunition was manufactured to be used in 2 cm Flak weapons. Other kinds than in existence included a number of different AP types. A high-velocity PzGr 40 round with a tungsten carbide core in an aluminium body existed in 20x138B caliber; as the Flak 30 was entering service, the Luftwaffe and Heer branches of the Wehrmacht had doubts about its effectiveness, given the ever-increasing speeds of low-altitude fighter-bombers and attack aircraft. The Army in particular felt the proper solution was the introduction of the 37 mm caliber weapons they had been developing since the 1920s, which had a rate of fire about the same as the Flak 38, but fired a round with eight times the weight.
This not only made the rounds deadlier on impact, but their higher energy and ballistic coefficient allowed them to travel much longer distances, allowing the gun to engage targets at longer ranges. This meant; the 20 mm weapons had always had weak development perspectives being reconfigured or redesigned just enough to allow the weapons to find use. Indeed, it came as a surprise when Rheinmetall introduced the 2 cm Flakvierling 38, which improved the weapon just enough to make it competitive once again; the term Vierling translates to "quadruplet" and refers to the four 20 mm autocannon constituting the design. The Flakvierling weapon consisted of quad-mounted 2 cm Flak 38 AA guns with collapsing seats, folding handles, ammunition racks; the mount had a triangular base with a jack at each leg for levelling the gun. The tracker elevated the mount manually using two handwheels; when raised, the weapon measured 307 cm high. Each of the four mounted; this meant that a maximum combined rate of fire of 1,400 rounds per minute was reduced to 800 rounds per minute for combat use – which would still require that an emptied magazine be replaced every six seconds, on each of the four guns.
This is the attainable rate of fire. Automatic weapons are limited to 100 rounds per minute per barrel to give time for the heat to dissipate, although this can be exceeded for short periods if the firing window is brief; the gun was fired by a set of two pedals — each of which fired two diametrically opposite barrels — in either semi-automatic or automatic mode. The effective vertical range was 2,200 metres, it was used just as against ground targets as it was against low-flying aircraft. The Flakvierling four-autocannon anti-aircraft ordnance system, when not mounted into any self-propelled mount, was transported on a Sd. Ah. 52 trailer, could be towed behind a variety of half-tracks or trucks, such as the Opel Blitz and the armored Sd. Kfz. 251 and un
The Soviet Navy was the naval arm of the Soviet Armed Forces. Referred to as the Red Fleet, the Soviet Navy was a large part of the Soviet Union's strategic plan in the event of a conflict with opposing super power, the United States, the North Atlantic Treaty Organization, or another conflict related to the Warsaw Pact of Eastern Europe; the influence of the Soviet Navy played a large role in the Cold War, as the majority of conflicts centered on naval forces. The Soviet Navy was divided into four major fleets: the Northern, Black Sea, Baltic Fleets; the Caspian Flotilla was a smaller force operating in the land-locked Caspian Sea. Main components of the Soviet Navy included Soviet Naval Aviation, Naval Infantry, Coastal Artillery. After the dissolution of the Soviet Union in 1991, Russia inherited the largest part of the Soviet Navy and reformed it into the Russian Navy, with smaller parts becoming the basis for navies of the newly independent post-Soviet states; the Soviet Navy was based on a republican naval force formed from the remnants of the Imperial Russian Navy, completely destroyed in the two Revolutions of 1917 during World War I, the following Russian Civil War, the Kronstadt rebellion in 1921.
During the revolutionary period, Russian sailors deserted their ships at will and neglected their duties. The officers were dispersed and most of the sailors walked off and left their ships. Work stopped in the shipyards; the Black Sea Fleet fared no better than the Baltic. The Bolshevik revolution disrupted its personnel, with mass murders of officers. At the end of April 1918, Imperial German troops moved along the Black Sea coast and entered Crimea and started to advance towards the Sevastopol naval base; the more effective ships were moved from Sevastopol to Novorossiysk where, after an ultimatum from Germany, they were scuttled by Vladimir Lenin's order. The ships remaining in Sevastopol were captured by the Germans and after the Armistice of 11 November 1918 on the Western Front which ended the War, additional Russian ships were confiscated by the British. On 1 April 1919, during the ensuing Russian Civil War when Red Army forces captured Crimea, the British Royal Navy squadron had to withdraw, but before leaving they damaged all the remaining battleships and sank thirteen new submarines.
When the opposing Czarist White Army captured Crimea in 1919, it rescued and reconditioned a few units. At the end of the civil war, Wrangel's fleet, a White flotilla, moved south through the Black Sea, Dardanelles straits and the Aegean Sea to the Mediterranean Sea to Bizerta in French Tunisia on the North Africa coast, where it was interned; the first ship of the revolutionary navy could be considered the rebellious Imperial Russian cruiser Aurora, built 1900, whose crew joined the communist Bolsheviks. Sailors of the Baltic fleet supplied the fighting force of the Bolsheviks led by Vladimir Lenin and Leon Trotsky during the October Revolution of November 1917 against the democratic provisional government of Alexander Kerensky established after the earlier first revolution of February against the Czar; some imperial vessels continued to serve after the revolution, albeit with different names. The Soviet Navy, established as the "Workers' and Peasants' Red Fleet" by a 1918 decree of the new Council of People's Commissars, installed as a temporary Russian revolutionary government, was less than service-ready during the interwar years of 1918 to 1941.
As the country's attentions were directed internally, the Navy did not have much funding or training. An indicator of its reputation was that the Soviets were not invited to participate in negotiations for the Washington Naval Treaty of 1921–1922, which limited the size and capabilities of the most powerful navies - British, Japanese, Italian; the greater part of the old fleet was sold by the Soviet government to post-war Germany for scrap. In the Baltic Sea there remained only three much-neglected battleships, two cruisers, some ten destroyers, a few submarines. Despite this state of affairs, the Baltic Fleet remained a significant naval formation, the Black Sea Fleet provided a basis for expansion. There existed some thirty minor-waterways combat flotillas. During the 1930s, as the industrialization of the Soviet Union proceeded, plans were made to expand the Soviet Navy into one of the most powerful in the world. Approved by the Labour and Defence Council in 1926, the Naval Shipbuilding Program included plans to construct twelve submarines.
Beginning 4 November 1926, Technical Bureau Nº 4, under the leadership of B. M. Malinin, managed the submarine construction works at the Baltic Shipyard. In subsequent years, 133 submarines were built to designs developed during Malinin's management. Additional developments included the formation of the Pacific Fleet in 1932 and the Northern Fleet in 1933; the forces were to be built around a core of powerful Sovetsky Soyuz-class battleships. This building program was only in its initial stages by the time the German invasion forced its suspension in 1941; the Soviet Navy had some minor action