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Wikipedia / Junkers

Junkers Flugzeug- und Motorenwerke AG (JFM, earlier JCO or JKO in World War I, English: Junkers Aircraft and Motor Works) more commonly Junkers , was a major German aircraft and aircraft engine manufacturer. It was founded in Dessau, Germany, in 1895 by Hugo Junkers, initially manufacturing boilers and radiatorss. During World War I and following the war, the company became famous for its pioneering all-metal aircraft. During World War II the company produced the German air force's planes, as well as piston and jet aircraft engines, albeit in the absence of its founder who had been removed by the Nazis in 1934.

History

Early inter-war period

In the immediate post-war era, Junkers used their J8 layout as the basis for the F-13, first flown on 25 June 1919 and certified airworthy in July of the same year. This four passenger monoplane was the world's first all-metal airliner. Of note, in addition to significant European sales, some twenty-five of these airplanes were delivered to North American customers under the Junkers-Larsen affiliate and were used primarily as airmail planes.

The Treaty of Versailles, signed only days after the F-13 flew, initially forbade any aircraft construction in Germany for several months. After that span of time, only the design of civilian aircraft was permitted to Germany. With a partial relocation of the Junkers firm to the Fili western suburb of Moscow, the Junkers firm was able to restart its aircraft manufacturing concern within the borders of the Soviet Union in 1922, the partly revitalized Junkers firm developed a series of progressively larger civil aircraft including the single-engined G.24 and three-engine G.31. Neither aircraft was a commercial success. With the expiration of treaty restrictions in 1926, Junkers introduced the Junkers W33 and Junkers W34 series, which did find significant commercial success via large production orders in passenger, freight hauling, and, somewhat later, military configurations. The W-33/W-34 series also set multiple aviation "firsts" including records for flight duration, flight distance, altitude, rocket-assisted take-off and inflight refueling between 1926 and 1930.

After previous study work, Junkers set up the Junkers Luftbild-Zentrale in Dessau in 1924 to produce aerial photographs for various purposes. Eight years later, due to the financial difficulties of the parent company, this branch was separated and continued to operate as Bild-Flug for a year until it was taken over by its main competitor, Hansa Luftbild.

Junkers' produced a design study in 1924 for a visit to the United States. The study outlined a four-engined 80-passenger plane, incorporating a forward canard wing, as well as a main wing, both of which were fitted above twin pylons. Called the Junkers J.1000 Super Duck passenger seating was to be provided both in the main wing and the hull sections of the craft. This Junkers design, including a scale model, was intended to illustrate an aircraft capable of trans-Atlantic operations of 8 to 10 hours and was completely revolutionary for its day.

It was in 1922 that American engineer William Bushnell Stout, and in 1924 that Soviet engineer Andrei Tupolev each adapted the Junkers corrugated duralumin airframe design technologies for their own initial examples of all-metal aircraft in their respective nations – for Stout, the Stout ST twin-engined naval torpedo bomber prototype aircraft, and for Tupolev, the Tupolev ANT-2 small passenger aircraft, who had the assistance of the Soviet government's TsAGI research center in achieving success with light-weight metal airframes.

The basic principles outlined in this design were later introduced in the Junkers G.38, which was introduced and put into regular service by Deutsche Luft Hansa. At the time of its introduction, this four-engined transport was the largest landplane in the world carrying thirty-four passengers and seven crew members. The G.38 sat some of its passengers in the wing area outboard of the fuselage, the front of which was covered with windows.

Also, in 1932, Junkers joint project with Maybach designed and built an aerodynamic car but found due to the depression that the market for high end luxury cars was saturated.

Financial troubles

Around 1931 the company suffered from a series of financial difficulties that led to the collapse of the group of companies. The existing shareholders pressured Hugo to leave the company. Hugo, however, was the patent holder on a wide variety of the technologies used in most of the existing Junkers designs, including many of their engines.

A plan was started to solve both problems by "buying out" Hugo's engine patent portfolio and placing it into the hands of a new company, the Junkers Motoren-Patentstelle GmbH, which was eventually formed in November 1932. The new company would then license the technologies back to the various companies, most notably what was then Junkers Motorenbau (one of many "Jumo" companies). However, before Junkers actually transferred his patents to the Patentstelle, the collapse of the Junkers consortium was solved by the sale of Junkers Thermo Technik GmbH to Robert Bosch GmbH, whose company still uses the brand name. Adolf Dethmann, a Communist activist and friend of Hugo, was appointed managing director.

Post World War II

Despite significant bomb damage to its factories, the Junkers company survived the Second World War and the formation of East Germany, and was reconstituted as Junkers GmbH and eventually merged into the MBB consortium (via joint venture Flugzeug-Union-Süd between Heinkel and Messerschmitt in 1958). Messerschmitt ended the joint venture in 1965 by acquiring control of JFM AG and absorbing it in 1967. Within West Germany, Junkers GmbH was engaged in research on the future of aerospace transportation during the fifties and early-1960s. During this period, Junkers employed the famous Austrian engineer and space travel theorist, Eugen Sänger, who in 1961 completed work for the design of an advanced orbital spacecraft at Junkers. Junkers GmbH was absorbed within MBB and the Junkers name disappeared in 1969.

Products

Aircraft

The Junkers firm's early aircraft were identified by the letter J for Junkers followed by an Arabic type number. From 1919 they introduced an additional sales designation using the same number but prefixed by a letter indicating the role of the aircraft:

  1. A = (suitable for either civil or military use),

  2. EF = (experimental aircraft),

  3. F = (aircraft),

  4. G = (large aircraft),

  5. H = aircraft built at Junkers' Moscow plant,

  6. K = (bomber),

  7. S = (special),

  8. T = (trainer aircraft),

  9. W = (seaplane).

Just once, the same number was used to identify two different completed types. This pair was the T23 and G23, both also known as J23.

During World War I, machines in service used the regular Idflieg aircraft designation system to specify their design's purpose, also promoted by the (Air Ministry), again a letter number system indicating role:

  1. CL = two-seat ground attack,

  2. D = single-seat biplane scout, by 1918 used for all single seat scouts,

  3. E = single-seat monoplane scout,

  4. J = two-seat armoured close support biplane.

The best known and most confusing example is the Junkers J4 armored-fuselage, all-metal sesquiplane, known to the military as the Junkers J.I.

The single letter company prefix was not replaced by the twin-letter Ju prefix until 1933. This RLM system from the Third Reich's air ministry applied to all German manufacturers; the first Junkers aircraft to receive a Ju number was the W33, so retrospectively it became the Ju33. However, earlier aircraft built in Moscow like the H21 were often described by a Ju number, e.g. Ju21.

Experimental

Designations used exclusively in the Soviet Union

  • Junkers EF 140, twin-engine jet bomber, development of EF131; completed post-war in USSR.

  • Junkers EF 145, possibly a Ju 88 or Ju 388 testbed at OKB-1

  • Junkers EF 150, twin-engine jet bomber, further development of EF140; largely Russian designed and completed post-war in USSR.

Aircraft engines

All Junkers diesel engines were two stroke, opposed piston designs, an arrangement he invented in the early 1890s. It was intended to provide an alternative to Nicholaus Otto's patented four stroke which would run on low grade fuels such as blast furnace waste gases. By 1896 Junkers engines were generating electrical power in steelworks.

  • Junkers Fo2, horizontal, petrol, c.1923.

  • Junkers L1, petrol, c. 1924.

  • Junkers L2, petrol, 1925.

  • Junkers L5, enlarged L 2, petrol, 1925.

  • Junkers Fo3, diesel, 1926.

  • Junkers L55, "double L5" (V12), petrol, 1927

  • Junkers L7, small version of L2, petrol; not flown.

  • Junkers Fo4, diesel, commercially called the Junkers SL1, 1928.

  • Junkers L8, petrol, geared, higher power development of L5, 1929.

  • Junkers L88, "double L8" (V12), petrol.

  • Jumo 204, development of the SL1, initially referred to as the Jumo 4, 1930.

  • Jumo 205, diesel, reduced displacement version of the Jumo 204, initially known as the Jumo 5, 1933.

  • Jumo 206, diesel, higher power version of 205, 1936.

  • Jumo 207, diesel, supercharged version of 205, 1939.

  • Jumo 208, diesel, enlarged variant of 205, c.1940

  • Jumo 209, diesel, unbuilt development of 207/208

  • Jumo 210, initially known as L10, petrol inverted V12, c. 1932.

  • Jumo 211, petrol, inverted V12, enlarged variant of 210, 1936.

  • Jumo 212, petrol, projected inverted V24 with two Jumo 211 engines.

  • Jumo 213, petrol, inverted V12, revised, improved version of 211, 1940.

  • Jumo 218, diesel, unbuilt 12 cylinder version with two 208 engines.

  • Jumo 222, petrol, 24-cylinder, 6-bank radial, 1939.

  • Jumo 223, diesel, experimental 24 cylinder with four 207 engines arranged in a box shape.

  • Jumo 224, diesel, higher power version of 223, development continued in the Soviet Union.

  • Jumo 225, petrol, projected 36-cylinder, multi-bank radial developed from the 222.

  • Junkers 109-004, turbojet, 1940.

  • Junkers 109-012, turbojet, few completed by Soviets, 1946.

  • Junkers 109-022, turboprop, project completed by Soviets, 1950.

See also

References

Bibliography