Tatra 12
Encyclopedia
Tatra 12 is a model of vintage automobile made by Czech manufacturer Tatra.
It was manufactured between 1923 and 1926. It was replaced by the Tatra 57
in 1932.
All Czech car manufacturers were making large and expensive cars at the beginning of 1920s, which only the rich could afford. Some companies tried to introduce an inexpensive design, which would be affordable for the middle class. Tatra's solution to this was the Tatra 11
of which the Tatra 12 is successor.
, Tatra's designer, came up with an revolutionary idea of a backbone tube
chassis
, which he introduced on Tatra 11
. Tatra 12 follows the same principles with the backbone tube, which has mounted the differential with swing half-axles at the rear. The gearbox has 4 speeds (+reverse) and the engine is on the top of it, while both are mounted on the front of the backbone tube.
The engine is a petrol flat two cylinder which is cooled by onslaught air. Thanks to this the expensive and heavy radiators could be avoided - this was an excellent idea at the time, when antifreeze
was rather problematic.
The front axle has suspension by transverse leaf springs. While Tatra 11 had drum brakes only on the rear wheels, Tatra 12 had drum brakes all around.
Weymann's
system was different. The wooden pieces were not mortised together, but only loosely put next to each other. The wooden pieces were merely touching each other and its ends were coated in a buffer material (often leather). The wooden pieces were joined together via steel strips. This type of bodywork wasn't totally firm, but it allowed natural shifts which occur as the wood gets dry or wet. Such shifts made it impossible for use of metal sheets, therefore the exterior was covered in artificial leather.
The cylinders were made from a special alloy, which allowed it to work even under extreme heat. The modified engine had about 30 hp at 5000 rpm (the standard version had about half). The car had also the tachometer
, unlike the production version. The front axle was similar to the one of Tatra 17
with swinging half axles (standard version had half axles only at the rear, while front was solid).
The bodywork itself was built in a manner similar to the aeroplane design of the era - from plywood; only the front bonnet was made from aluminium plate. This made the body weigh only around 25 kg (55.1 lb), while the whole car weighed 560 kg (1,234.6 lb).
The car was able to reach speeds up to 120 km/h (74.6 mph) (almost twice of the standard version) and it therefore needed better brakes. To allow easier re-fuelling the fuel tank with capacity of 60 litre was place behind the rear seats. To its advantage Tatra 12 didn't need stops for change of coolant (as the engine was air-cooled). The factory made the cars with mud-guards, however they were usually stripped for a race.
The Targa Florio cars took part in many races, i.e. in Stuttgart, Ecce Homo, or the Great Russian contest of reliability. In 1925 debuting Tatra 12s took part in the Sicilian Targa Florio
race, after which the race models were later named. The two cars driven by Fritz Huckel and Karel Sponer took both first and second position in the category of under 1100 cc. Huckel had beaten the track record by 26 minutes and Sponer had beaten it by 21 minutes.
It was manufactured between 1923 and 1926. It was replaced by the Tatra 57
Tatra 57
Tatra 57 is an automobile launched by Tatra company Tatra 57 is an automobile launched by Tatra company Tatra 57 is an automobile launched by Tatra company (in Czech: Závody Tatra, official name: Závody Tatra akciová společnost or Ringhoffer - Tatra company, also later known as Tatra Kopřivnice, in...
in 1932.
All Czech car manufacturers were making large and expensive cars at the beginning of 1920s, which only the rich could afford. Some companies tried to introduce an inexpensive design, which would be affordable for the middle class. Tatra's solution to this was the Tatra 11
Tatra 11
The Tatra T11 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:...
of which the Tatra 12 is successor.
Design
Hans LedwinkaHans Ledwinka
Hans Ledwinka was an Austrian automobile designer.- Youth :Ledwinka was born was born in Klosterneuburg , near Vienna, then part of the Austro-Hungarian Empire....
, Tatra's designer, came up with an revolutionary idea of a backbone tube
Backbone chassis
Backbone tube chassis is a type of an automobile construction chassis that is similar to the body-on-frame design. Instead of a two-dimensional ladder type structure, it consists of a strong tubular backbone that connects the front and rear suspension attachment areas...
chassis
Chassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
, which he introduced on Tatra 11
Tatra 11
The Tatra T11 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:...
. Tatra 12 follows the same principles with the backbone tube, which has mounted the differential with swing half-axles at the rear. The gearbox has 4 speeds (+reverse) and the engine is on the top of it, while both are mounted on the front of the backbone tube.
The engine is a petrol flat two cylinder which is cooled by onslaught air. Thanks to this the expensive and heavy radiators could be avoided - this was an excellent idea at the time, when antifreeze
Antifreeze
Antifreeze is a freeze preventive used in internal combustion engines and other heat transfer applications, such as HVAC chillers and solar water heaters....
was rather problematic.
The front axle has suspension by transverse leaf springs. While Tatra 11 had drum brakes only on the rear wheels, Tatra 12 had drum brakes all around.
Versions
The chassis itself weighs around 500 kg (1,102.3 lb). There were many different bodies built on it (see picture). The chassis itself was also sold to other manufacturers to build their own car bodies on it.
Weymann motor body
Most car bodies of the era were built by nailing metal plates on the wooden skeleton of the car. The wood was usually very rigid, often the ash-tree was used. This made the body very firm, but rather heavy.Weymann's
Weymann Fabric Bodies
Weymann Fabric Bodies is a patented design system for fuselages for aircraft and superlight coachwork for motor vehicles. The system used a patent-jointed wood frame covered in fabric...
system was different. The wooden pieces were not mortised together, but only loosely put next to each other. The wooden pieces were merely touching each other and its ends were coated in a buffer material (often leather). The wooden pieces were joined together via steel strips. This type of bodywork wasn't totally firm, but it allowed natural shifts which occur as the wood gets dry or wet. Such shifts made it impossible for use of metal sheets, therefore the exterior was covered in artificial leather.
Targa Florio
The Targa Florio version was quite different from the serial production models. The engine and the bodywork were changed the most, but also the chassis was altered by changing the front axle.The cylinders were made from a special alloy, which allowed it to work even under extreme heat. The modified engine had about 30 hp at 5000 rpm (the standard version had about half). The car had also the tachometer
Tachometer
A tachometer is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute on a calibrated analogue dial, but digital displays are increasingly common...
, unlike the production version. The front axle was similar to the one of Tatra 17
Tatra 17
Tatra 17 is a vintage luxury automobile produced by the Czech manufacturer Tatra from 1925-1929.-Engine:The vehicle had a liquid-cooled six-cylinder OHC in-line Tatra 17 engine with and 35 hp power. This new block engine by Bevel had an aluminum cylinder head and the first Tatras to have a...
with swinging half axles (standard version had half axles only at the rear, while front was solid).
The bodywork itself was built in a manner similar to the aeroplane design of the era - from plywood; only the front bonnet was made from aluminium plate. This made the body weigh only around 25 kg (55.1 lb), while the whole car weighed 560 kg (1,234.6 lb).
The car was able to reach speeds up to 120 km/h (74.6 mph) (almost twice of the standard version) and it therefore needed better brakes. To allow easier re-fuelling the fuel tank with capacity of 60 litre was place behind the rear seats. To its advantage Tatra 12 didn't need stops for change of coolant (as the engine was air-cooled). The factory made the cars with mud-guards, however they were usually stripped for a race.
The Targa Florio cars took part in many races, i.e. in Stuttgart, Ecce Homo, or the Great Russian contest of reliability. In 1925 debuting Tatra 12s took part in the Sicilian Targa Florio
Targa Florio
The Targa Florio was an open road endurance automobile race held in the mountains of Sicily near Palermo. Founded in 1906, it was the oldest sports car racing event, part of the World Sportscar Championship between 1955 and 1973...
race, after which the race models were later named. The two cars driven by Fritz Huckel and Karel Sponer took both first and second position in the category of under 1100 cc. Huckel had beaten the track record by 26 minutes and Sponer had beaten it by 21 minutes.