Tatra- The Other Aircooled - Up To 1945

Most people have never heard of the Czech auto firm of Tatra. Despite producing quality cars from 1897, right up to the early 1990's, Tatra was a very forward looking and technologically advanced automaker.

However, the firm that could have done so well had two historic events that effectively prevented it from ever becoming a mainstream contender. Firstly, Tatra was involved before the war in production of innovative aircooled Peoples cars?, when the Germans moved in 1938 ? while production went on in limited numbers ? the company could never mass produce a rival to Germany's own peoples car. Secondly, the firm fell under the Soviet sphere after the war, The Russians nearly killed the firm, but eventually decided to let Tatra produce large, relatively luxurious models for the Czech state bureaucrats and officials and left Skoda to concentrate on cars for the masses.

What makes Tatra so important was that they were doing exactly what Ferdinand Porsche was looking into, cheaper cars for the masses. Both Hans Ledwinka of Tatra, and Ferdinand Porsche were contemporary car designers, and would have known about each other work. Both favoured backbone chassis and rear mounted aircooled engines. In most ways Tatra's designed were more advanced, and Tatra easily beat Porsche in the first production of this type of car (indeed Tatra successfully sued VW in the 1950's). Both approaches were lucky to survive the war, VW was lucky enough to come under British control, and then German management. Tatra survived the war, but under Soviet control would never flourish to rival the western auto companies.

In many ways the fate of Tatra would have been that of Volkswagen, if they had been unlucky enough to fall under the Iron Curtain.

Tatra-Fritzmaurice

The streamlining era at Tatra was foreshadowed in October 1933 by a special prototype displayed by the British Tatra consessionaire, one D. Fitzmaurice, at the Olympia Motor Show in London, England. It was called the Tatra-Fitzmaurice and had a streamlined body designed by D. Fitzmaurice and made by Thomas Harrington Ltd. (of England) mounted on a special Tatra-supplied chassis with a front-mounted 1.48-litre air-cooled 4-cylinder engine (a modified T75 unit). It was offered for sale at a very high price and no copies were built.

The Tatra goes rear aircooled

Nineteen-thirty-three also marked the beginning of the era of Tatra automobiles with rear-mounted (directly behind the rear axle) aircooled engines, a requirement for the truly aerodynamically efficient automobile - at least as established scientifically by the Hungarian streamlining specialist Paul Jaray. As well this engine placement had an effect of reducing engine noise (air cooled units do tend to get noisy) inside the vehicle and allowed the front of a car to be as short as possible while prompting a long tail, both of which were aids in reducing aerodynamic drag. Of course one disadvantage of placing the engine in the rear is that it creates difficulty in attaining good weight distribution. The somewhat related concept of positioning the engine in front of the rear axle (so-called "mid engine" layout) would be better in this regard but very impractical for a multiple-passenger luxury automobile. And as a side note, having the engine and driving wheels on the same end has advantages, such as weight reduction, less efficiency loss in the drive, no vibrations caused by a long drive shaft, and a flat floor.

The V570 prototype

The importance of streamlining in automobiles cannot be overlooked.

Aerodynamic efficiency has numerous advantages, some of the more significant are reduced fuel consumption, increased stability, possibility of higher speeds, and greater safety. In addition, it obviously creates an opportunity for interesting styling ideas.

Tatra's first concept

Since about 1930 the Tatra design team, headed by Hans Ledwinka and composed notably of Erich Uberlacker and a few other engineers, had been considering the concept of mounting an air-cooled engine at the posterior end of a back-bone chassis.

In 1931 an experimental prototype rear-engined Tatra was constructed with a conventional body which looked to be made up of standard components. It must have been successful as indicated by another prototype developed in 1933, the V570. This was a very advanced study-vehicle with an aerodynamic body of steel sheets covering a wooden structure and capable of seating 4 persons. A 854cc horizontally-opposed 2-cylinder air-cooled engine drove the rear wheels.

Production - the Tatra T77

The 5th of March, 1934, is certainly a date to remember. On that day took place the official introduction of the Tatra 77, having the honour of being the world's first serially produced aerodynamically styled automobile powered by an air-cooled rear-mounted engine.

This massive and roomy, seating for six provided, luxury car had an exceptionally low coefficient of drag. The occupants sat low and comfortably between the axles of this V8-powered and astonishingly low 4-door automobile. With the steering wheel situated centrally at front, the driver must have had quite a view out the 45-degree slanted windshield. There was lots of luggage space, above the rear suspension and in the nose, where the spare tires and battery resided. The efficiently streamlined body, complete with stabilising dorsal fin, was mounted on a central tube chassis welded to a box-type frame which forked at back to surround the motor.

Unfortunately the placement of the engine so far back did cause weight-distribution problems coupled with the swing-axle suspension which greatly affected handling, something that required quite a bit of getting used to. Nonetheless, the T77 was still a remarkable achievement considering, among other things, that its relatively small 2.97-litre power-plant propelled it to a top speed of over 140 km/h. The then chief engineer Erich Uberlacker was mainly responsible for the design and actually suggested the use of aerodynamic bodywork, for the construction of which a license from the Budd Manufacturing Co. of USA (where incidentally Hans Ledwinka's relative Joseph Ledwinka worked) was obtained.

1935 Tatra T77a

In 1935 followed the improved Tatra 77a. An extra central headlight was added and could optionally be made to turn with the steering wheel (more precisely, three different directions of the headlight were possible), that must have been quite the experience for night drivers! Increasing the capacity of the V8 to 3.4-litres raised output to 75 bhp and maximum speed to 150 km/h. Driving characteristics were also improved and the styling (aesthetically speaking) was cleaned-up slightly.

Aerodynamics were still awesome with the drag coefficient of 0.21 (the cd of the original 77 is not exactly known but presumably is very similar).

The production of both the T77 and T77a was very limited, numbering 105 of the former and no more than 150 of the latter. It is also important to note that, since both models (like most Tatra models) were hand built, no two were exactly alike.

Source:  Wheelspin.com