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The Czechoslovakian Tatra 77 (T77) is by many considered to be the first serial-produced, truly aerodynamically-designed automobile. It was developed by
Hans Ledwinka Hans Ledwinka (14 February 1878 – 2 March 1967) was an Austrian automobile designer. Youth Ledwinka was born in Klosterneuburg (Lower Austria), near Vienna, then part of the Austro-Hungarian Empire. He started his career as a mechanic, a ...
and
Paul Jaray Paul Jaray ( Hungarian: ''Járay Pál''; 11 March 1889 – 22 September 1974) was an engineer, designer, and a pioneer of automotive streamlining. Life Jaray, of Hungarian-Jewish descent, was born in Vienna. Jaray studied at ''Maschinenbauschul ...
, the Zeppelin aerodynamic engineer. Launched in 1934, the Tatra 77 is a coach-built automobile, constructed on a platform chassis with a pressed box-section steel backbone rather than Tatra's trademark tubular chassis, and is powered by a rear-mounted 2.97-litre air-cooled V8 engine, in later series increased to a 3.4-litre engine. It possessed advanced engineering features, such as overhead valves, hemispherical combustion chambers, a
dry sump A dry-sump system is a method to manage the lubricating motor oil in four-stroke and large two-stroke piston driven internal combustion engines. The dry-sump system uses two or more oil pumps and a separate oil reservoir, as opposed to a conve ...
, fully independent suspension, rear swing axles and extensive use of lightweight magnesium alloy for the engine, transmission, suspension and body. The average drag coefficient of a 1:5 model of Tatra 77 was recorded as 0.2455. The later model T77a has a top speed of over due to its advanced aerodynamic design which delivers an exceptionally low
drag coefficient In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag equ ...
of 0.212,Optimization and computational fluid dynamics, Gàbor Janiga, Springer, 2008, page 196Winning the oil endgame: innovation for profits, jobs and security, Amory B. Lovins, Rocky Mountain Institute, 2004, page 53 although some sources claim that this is the coefficient of a 1:5 scale model, not of the car itself.Ivan Margolius, 'Model Behaviour', ''Octane'', February 2012, pp. 38-9


History

The Tatra Company began manufacturing cars in 1897 in
Kopřivnice Kopřivnice (; german: Nesselsdorf) is a town in the Moravian-Silesian Region of the Czech Republic. It has about 21,000 inhabitants. It is an industrial town, known especially for the vehicle manufacturer Tatra. Administrative parts Villages of ...
,
Moravia Moravia ( , also , ; cs, Morava ; german: link=yes, Mähren ; pl, Morawy ; szl, Morawa; la, Moravia) is a historical region in the east of the Czech Republic and one of three historical Czech lands, with Bohemia and Czech Silesia. The me ...
, in today's
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
, making it the third-oldest still-existing automobile manufacturer in the world. Under the direction of
Hans Ledwinka Hans Ledwinka (14 February 1878 – 2 March 1967) was an Austrian automobile designer. Youth Ledwinka was born in Klosterneuburg (Lower Austria), near Vienna, then part of the Austro-Hungarian Empire. He started his career as a mechanic, a ...
, the company employed many of the genius minds of automotive history, including Erich Übelacker and consultant
Paul Jaray Paul Jaray ( Hungarian: ''Járay Pál''; 11 March 1889 – 22 September 1974) was an engineer, designer, and a pioneer of automotive streamlining. Life Jaray, of Hungarian-Jewish descent, was born in Vienna. Jaray studied at ''Maschinenbauschul ...
, who together designed the Tatra 77.Ivan Margolius and John G. Henry, ''Tatra - The Legacy of Hans Ledwinka'', SAF Publishing, Harrow 1990.


Paul Jaray and Tatra V570

Paul Jaray first worked at
Luftschiffbau Zeppelin Luftschiffbau Zeppelin GmbH is a German aircraft manufacturing company. It is perhaps best known for its leading role in the design and manufacture of rigid airships, commonly referred to as ''Zeppelins'' due to the company's prominence. The name ...
(LZ) where he gained experience in the aerodynamic design of airships. He used his access to LZ's
wind tunnel Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...
s and subsequently established streamlining principles for car design. In 1927 he founded a company specializing in developing streamlined car bodies and selling issuing licences to major vehicle manufacturers. Tatra was the only manufacturer to incorporate Jaray's streamlining principles into their series car production, starting with the Tatra 77. Before designing the large, luxurious T77, Jaray designed an aerodynamic body for the Tatra 57, a mid-range model. This prototype was not developed further and failed to reach production. Instead, Jaray constructed two prototypes for a concept designated the
Tatra V570 The Tatra V570 was a prototype early 1930s car developed by a team led by Hans Ledwinka and Paul Jaray. The aim of the construction team was to develop a cheap people's car with an aerodynamic body. However the company's management decided that t ...
, which more closely conformed to his aerodynamic streamlining principles, featuring
beetle-shaped body


Decision to make luxurious state-of-the-art car

However, at the time Tatra already had a cheap, strongly-selling car in its production range, which was moreover popular due to its continuation of the tradition of simplicity and ultra-reliability inaugurated by the
Tatra 11 The Tatra T11 is an automobile that was produced from 1923 through 1927. It was the first Tatra model to use the unique combination of major components that are still in use on the trucks produced by Tatra to this day. Origins Hans Ledwinka crea ...
. Although Tatra management saw the advantages of Jaray's concept, they believed that the new model would make sense only as an additional model with limited production, which meant that it should be aimed at the top of the automobile market. Ledwinka's team subsequently stopped work on the V570 and concentrated on designing large luxury cars. Tatra aimed to make state-of-the-art cars that would be fast, stable, nearly silent, economical and built to the most rigorous engineering standards, as well as reflect modern aerodynamic research.


Unique engine

The T77/77A cars were quite probably the last production use of the "walking-beam" valvetrain principle, their dry-sump air/oil-cooled V8 engines having overhead valves in hemispherical heads, but no pushrods. Instead the valves are opened by enormous drilled rockers operated by a single high camshaft between the two cylinder banks' heads, and pivoted inboard of their centres to extend the lift applied by the cams. The principle had been used much earlier in the
Duesenberg Duesenberg Automobile and Motors Company, Inc. was an American race car, racing and luxury car, luxury automobile manufacturer founded in Indianapolis, Indiana, by brothers Fred Duesenberg, Fred and August Duesenberg in 1920. The company is ...
16-valve straight-4 low-twin-cam racing engine, later adopted by Rochester for use in passenger cars, but Tatra's use of a single camshaft to open the valves of a V8 without pushrods, rather than two low shafts on a straight engine, must be unique. A consequence is that the mechanical layout is much less obvious to the observer, with the big box-shaped engine giving few immediate clues to its V configuration, unlike its T87 OHC successor. Belt-driven squirrel fans in cast alloy ducting draw air forward, up and around the four shrouded pairs of finned iron cylinders, and a large hinged alloy cover maintains a warm environment for the carburettor in winter.


Public response

Hans Ledwinka was the chief designer responsible for the development of the new car, while Erich Übelacker was responsible for the body. Development was very secretive until the last moments of the official presentation on March 5, 1934, at Tatra's offices in
Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate ...
. The car was demonstrated on the road from Prague to
Karlovy Vary Karlovy Vary (; german: Karlsbad, formerly also spelled ''Carlsbad'' in English) is a spa town, spa city in the Karlovy Vary Region of the Czech Republic. It has about 46,000 inhabitants. It lies on the confluence of the rivers Ohře and Teplá. ...
, where it easily reached , and amazed journalists with its great handling and comfortable ride at speeds of about . That same year the T77 was presented at the
Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...
motor show, where it became the centre of attention due not only to its atypical design but also to its performance. There were even demonstration rides after doubt was cast on the ability of the car to reach with a mere of engine power: normally at that time twice the power was required for a car to reach such a speed. Director
Maurice Elvey Maurice Elvey (11 November 1887 – 28 August 1967) was one of the most prolific film directors in British history. He directed nearly 200 films between 1913 and 1957. During the silent film era he directed as many as twenty films per year. He a ...
was so amazed by the looks of the car that he used the T77 in his science-fiction movie '' The Transatlantic Tunnel''.


Notable owners

The Tatra 77 was the particular favourite of Tatra design engineer Erich Übelacker, who owned and used a T77 himself from 1934. Other famous owners of T77s were
Miloš Havel Miloš Havel (3 November 1899 – 25 February 1968) was a Czech film producer and studio executive. Havel was a director of the film production company Lucernafilm, which was founded by his father in 1912. He was also a chairman of the film studio ...
, the proprietor of the film studios in Prague, who bought a T77 in 1935, Austrian car designer
Edmund Rumpler Edmund Elias Rumpler (4 January 1872 – 7 September 1940) was an Austrian automobile and aircraft designer. Born in Vienna, then Austro-Hungarian Empire (now Austria),Wise 1974, p.1964 he worked mainly in Germany.Lyons 1988, p.73 An automo ...
, who designed the aerodynamic
Rumpler Tropfenwagen The Rumpler Tropfenwagen ("Rumpler drop car", named after its raindrop shape) was a car developed by Austrian engineer Edmund Rumpler. The Tropfenwagen Aerodynamics Rumpler, born in Vienna, was known as a designer of aircraft when at the 1921 Ber ...
in 1921,
Edvard Beneš Edvard Beneš (; 28 May 1884 – 3 September 1948) was a Czech politician and statesman who served as the president of Czechoslovakia from 1935 to 1938, and again from 1945 to 1948. He also led the Czechoslovak government-in-exile 1939 to 1945 ...
, the 1930s minister of Foreign Affairs and later president of Czechoslovakia, who both owned a T77a.


Design

A number of designers around the world were trying to construct an aerodynamic car at the time, but Tatra was the first one to successfully introduce it into serial production. There were numerous reasons why Tatra designers took such a revolutionary approach to the conception of the new car: First of all it was their aim to reduce drag, mostly air-drag, which increases with the
square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length adj ...
of the speed. A car with a more standard body shape of the era needed a very powerful engine to reach higher speeds. The Tatra's new body shape was tested in a
wind tunnel Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...
. However, the new requirements this brought about resulted in far-reaching changes to the car's design. The requirement of a small front face area limited the car's height, which in turn required the use of a flat floor. That led to putting the engine in the rear of the car, directly above the driven axle. Subsequently there was no need for a floor tunnel with a
drive shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power (physics), power and torque and rotation, usually ...
and exhaust pipes, which contributed to a reduction in weight. As the designers wanted to reduce the
rolling resistance Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy nee ...
, they did their best to produce an engine as light as possible: an air-cooled V8 with a
crank case In a reciprocating engine, piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, r ...
made from elektron, a magnesium alloy. The
gearbox Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differe ...
was also made from elektron, and it was positioned in front of the engine and rear axle. The rear position of the engine was favourable for air cooling, while the
oil cooler Oil cooling is the use of engine oil as a coolant, typically to remove surplus heat from an internal combustion engine. The hot engine transfers heat to the oil which then usually passes through a heat-exchanger, typically a type of radiator kno ...
,
battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...
and spare wheel were positioned in the front of the car. The frameless body was characterized by its central structural member, which was firmly welded to the floor panels and which covered the linkage to the brakes, gearbox, etc. The front of the car had a basically rectangular
cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Abs ...
and was rounded all the way to the floor. The front bumper covered the rounded fenders, while the lower halves of the lights were embedded in the bonnet. The rear of the car had a continuously sloping form and was divided by a vertical fin which started at the rear end of the roof and ended almost at the rear end of the car. The rear wheels had aerodynamic covers. The door handles were embedded into the door panels, from which only the door hinges protruded slightly. The car had no rear window, limiting rear visibility to what could be discerned through slits in the sheet metal. The first prototype of 1933 had a split windscreen, while other prototypes had a single-piece windscreen or even one formed from three separate pieces of glass with one large central piece and two side parts angled sharply and flowing into the sides of the body. Air was directed to the engine by rectangular ventilation inlets behind the side windows, and exited the engine compartment through vents at the rear. At the time, Tatra registered numerous patents regarding air flow to the rear engine compartment. Later the rear part of the body was widened so that both the rear fenders and door hinges were embedded into the bodywork itself. The air now flowed through transverse inlets which were raised above the rear of the rounded roof. The trailing edge was also raised.


Tatra 77a

In 1935 the T77 was updated and improved, which resulted in the T77a. The capacity of the V8 was increased to 3.4 L (207 cubic inches). This was achieved by enlarging the bore diameter from . The new motor increased output to and maximum speed to . The front now had three headlamps of which the central unit was not, as has been suggested, linked to the steering on some models. The central headlight never moved with the front wheels, but had an electro-magnetic system enabling the reflector to move to illuminate the kerbs, as street illumination was poor at the time. Some T77s and T77a models were also equipped with canvas
Webasto Webasto SE is a company based in Stockdorf, Germany which makes sunroofs, electric-car chargers and air-conditioning systems. Holger Engelmann is the CEO of the company. History Coronavirus outbreak Webasto owns 11 locations in China, in ...
roofs. The smooth body of the T77a gave a coefficient of aerodynamic drag of 0.212. This is an incredibly low value even for today's cars: only a few modern prototypes are able to achieve this figure. Some sources, though, claim that this figure was based on a 1:5 scale-model test.


Versions

The Tatra 77 was a hand-built car with a leather interior. Some cars had a glass partition between the front and rear seats. A sliding roof was available. An unusual feature on a few of the T77 models was a central position for the steering wheel in the dashboard. The front-seat passengers were seated on either side of the driver and the seats placed slightly rearwards as in the modern-day
McLaren F1 The McLaren F1 is a sports car designed and manufactured by British automobile manufacturer McLaren Cars, and powered by the BMW S70/2 V12 engine. The original concept was conceived by Gordon Murray. Murray was able to convince Ron Dennis to ...
. All other T77's had the steering wheel on the right-hand side as Czechoslovakia (like a number of other European countries) drove on the left before the Second World War. The unique car pictured here is the two-door coupé prototype used by Erich Übelacker. This one also had the more powerful engine from the later
Tatra 87 The Tatra 87 (T87) is a car built by Czechoslovak manufacturer Tatra. It was powered by a rear-mounted 2.9-litre air-cooled 90-degree overhead cam V8 engine that produced 85 horsepower and could drive the car at nearly . It is ranked among the f ...
.


Further development

Ledwinka was not entirely satisfied with the T77's handling, which was hampered by the car's rather heavy rear. He started work on a successor to the T77, which was to be lighter and have improved weight distribution. Tatra achieved just that with the now-famous
Tatra 87 The Tatra 87 (T87) is a car built by Czechoslovak manufacturer Tatra. It was powered by a rear-mounted 2.9-litre air-cooled 90-degree overhead cam V8 engine that produced 85 horsepower and could drive the car at nearly . It is ranked among the f ...
that was introduced in 1936.


In culture

A Tatra 77 features in the 1935 film '' The Tunnel'' at 17:23, and again at 58:30. A 1936 Tatra 77 was shown at the
Victoria & Albert Museum The Victoria and Albert Museum (often abbreviated as the V&A) in London is the world's largest museum of applied arts, decorative arts and design, housing a permanent collection of over 2.27 million objects. It was founded in 1852 and nam ...
in London from November 2019 to April 2020 included in their exhibition "Cars: Accelerating the Modern World".


See also


Streamlined Tatras *
Tatra V570 The Tatra V570 was a prototype early 1930s car developed by a team led by Hans Ledwinka and Paul Jaray. The aim of the construction team was to develop a cheap people's car with an aerodynamic body. However the company's management decided that t ...
''1931, 1933'' *Tatra 77 ''1933-1938'' *
Tatra 87 The Tatra 87 (T87) is a car built by Czechoslovak manufacturer Tatra. It was powered by a rear-mounted 2.9-litre air-cooled 90-degree overhead cam V8 engine that produced 85 horsepower and could drive the car at nearly . It is ranked among the f ...
''1936-1950'' *
Tatra 97 The Tatra 97 (T97) is a Czechoslovak mid-size car built by Tatra in Kopřivnice, Moravia from 1936 to 1939. History The Tatra 97 was designed to complement two full-size cars in the Tatra range: the Tatra 77 launched in 1934 and the Tatra 87 lau ...
''1936-1939'' *
Tatra 600 Tatraplan The Tatra 600, named the Tatraplan, was a rear-engined large family car (D-segment in Europe) produced from 1948 to 1952 by the Czech manufacturer Tatra. The first prototype was finished in 1946. History After World War II, Tatra continued its ...
''1946-1952'' *
Tatra 603 The Tatra 603 is a large rear-engined luxury car which was produced by the Czechoslovak company Tatra from 1956 to 1975. It was a continuation of the series of Tatra streamlined sedans which began with the Tatra 77. In Socialist Czechoslovakia, ...
''1956-1975''
*
Tatra (car) Tatra is a Czech vehicle manufacturer from Kopřivnice. It is owned by the ''Tatra Trucks'' company, and it is the third oldest company in the world producing cars with an unbroken history. The company was founded in 1850 as ''Ignatz Schustal ...
* Streamliner: Automobiles - for overview of early aerodynamic cars ;Early aerodynamic cars, chronologically: *
Rumpler Tropfenwagen The Rumpler Tropfenwagen ("Rumpler drop car", named after its raindrop shape) was a car developed by Austrian engineer Edmund Rumpler. The Tropfenwagen Aerodynamics Rumpler, born in Vienna, was known as a designer of aircraft when at the 1921 Ber ...
(1921), first aerodynamic "teardrop" car to be designed and serially produced (about 100 units built) *Persu car (1922–23), designed by Romanian engineer
Aurel Persu Aurel Persu (26 December 1890 – 5 May 1977) was a Romanian engineer and pioneer car designer, the first to place the wheels inside the body of the car as part of his attempt to reach the perfect aerodynamic shape for automobiles.
, improved on the Tropfenwagen by placing the wheels inside the car body *Burney cars (1929-1931), working prototypes designed by Dennis Burney and manufactured by Streamline Cars *
Dymaxion car The streamlined Dymaxion car was designed by American inventor Buckminster Fuller during the Great Depression and featured prominently at Chicago's 1933/1934 World's Fair. Fuller built three experimental prototypes with naval architect Star ...
(1933), US "teardrop" car *
Stout Scarab The Stout Scarab is a streamlined 1930–1940s American car, designed by William Bushnell Stout and manufactured by Stout Engineering Laboratories and later by Stout Motor Car Company of Detroit, Michigan. The Stout Scarab is credited by s ...
(1932–35), US "teardrop" car *
Pierce Silver Arrow The Pierce Silver Arrow was a luxury car produced by American luxury automaker Pierce-Arrow in 1933. Designed by Phillip O. Wright, it was introduced at the 1933 New York Auto Show The New York International Auto Show is an annual auto sho ...
(1933), US streamline concept car * Chrysler Airflow (1934–37), US streamline car *
Schlörwagen The ''Schlörwagen'' (nicknamed "Göttingen Egg" or "Pillbug") was a prototype aerodynamic rear-engine passenger vehicle developed by Karl Schlör (1911–1997) and presented to the public at the 1939 Berlin Auto Show. It never went into producti ...
(1939), German prototype "teardrop" car, never produced


Literature

Margolius, Ivan & Henry, John G., ''Tatra - The Legacy of Hans Ledwinka'', Veloce Publishing, Dorchester 2015, &


References


Further reading

*


External links


Jay visits John Long at Pebble Beach to get a close-up look at his rare Tatra 77aTatraclub.at: Tatra 77a riding (video)Tatraclub.sk: Contemporary T77 materialsOriginal brochure (czech)Gallery of beautifully restored silver T77a
{{Tatra models Cars of the Czech Republic 77 Cars powered by rear-mounted 8-cylinder engines Cars introduced in 1934 Streamliner cars Automobiles with backbone chassis