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1934 Tatra T77

Nesseldorfer Waggonfabrik, of Koprivnice, Czechoslovakia, was founded in 1897 and re-named in 1927 after the prominent mountain range on the Slovak-Poland border. Austrian-born designer Hans Ledwinka, who was with Tatra's predecessor company, engineered a torsionally rigid backbone chassis with swing-axle suspension and a front-mounted, twin-cylinder air-cooled engine for the Tatra T11, introduced in 1923. The Tatra T12 that followed continued to employ these mechanical components, while the T17 of 1926 added fully independent suspension and a water-cooled six. Through the 1930s, a series of models that used air-cooled four-cylinder power and aerodynamic design principles became paramount. Assisted by the Czech engineer Erich Übelacker, Ledwinka investigated the aerodynamic principles of Paul Jaray, who had designed airships for Luftschiffbau Zeppelin. The Tatra T77, introduced in 1934, was the result of these studies and has been called the world's first serially produced, aerodynamically designed automobile.

The Tatra T77

The Tatra 77 (T77) was a six-seat luxury automobile powered by a rear-mounted, three-liter air-cooled V8 engine and was capable of 87 mph. Its logical successor, the T87, was introduced in 1936 and improved upon the T77 with a drag coefficient of 0.36, better fuel economy, a top speed of 150 km/h, and improved handling.

Production of the Tatra T77 lasted from 1934 to 1935 and the T77a from 1935 to 1938, with total production being 249 units. Of those, 106 examples were the T77, including the pre-production chassis. These hand-built automobiles had a leather interior, with a few receiving a glass partition between the front and rear seats. A sliding canvas Webasto roof was available.

Although most famous on the modern-day McLaren F1, the Tatra T77 used a central position for the steering wheel in the dashboard. The driver was seated in the center, slightly ahead of the passenger seats on either side.

Mechanical Specification

Shedding the company's traditional tubular chassis, the Tatra 77 used a platform chassis with a pressed box-section steel backbone. The front of the car was a rectangular cross-section that was rounded to the floor. It had a 124-inch wheelbase, an overall length of 196.9 inches (as long as 204.7 inches), a width of 65 inches, and stood 55.9 inches tall (as tall as 59.1 inches). The suspension was fully independent with twin transverse leaf springs and rear swing axles. Four-wheel hydraulic drum brakes provided the stopping power.

The 2.97-liter air-cooled V8 engine was mounted in the back, directly above the driven axle. This placement allowed for a small frontal area with a lower hood line. This allowed for a flat floor and eliminated the need for a floor tunnel with a drive shaft and exhaust pipes, reducing the overall weight of the vehicle even further. The engine had overhead valves, dry sump lubrication, and hemispherical combustion chambers (overhead valves in hemispherical heads but no pushrods). The valves opened via drilled rockers operated by a single high camshaft between the two cylinder banks' heads. As they pivoted inboard of their centers, it extended the lift applied by the cams. This engine was one of the last production unit to use this 'walking-beam' valvetrain principle. Initially, it developed 60 horsepower, later increasing to 75 horsepower.

Air was directed to the engine via rectangular ventilation inlets behind the side windows. Belt-driven squirrel fans drew air forward, up and around the finned iron cylinders. Vents in the rear bodywork allowed hot air to exit.

Much of the suspension, engine, and body was formed from lightweight magnesium alloy. The crankcase and gearbox were formed from Elektron, a magnesium alloy. The four-speed manual transmission was placed ahead of the engine and rear axle. The battery, spare wheels, and oiler cooler were positioned in the front of the car. With most of the mechanical components (and weight) in the rear, the T77 suffered from handling issues. Ledwinka would work to resolve this problem, which he did with the Tatra 87 that was introduced in 1936.

Aerodynmaic Design

The curvaceous body had a low drag coefficient of 0.2455, while the T77a reduced that further to 0.212. Tatra designers preferred a shape that minimized air drag, with the design crafted through the use of a wind tunnel (a 1:5 scale model of the T77 was tested in a wind tunnel in period). With a more efficient shape, a less powerful engine was needed to reach the speeds and match the performance of more traditional 'square' designs with larger and more powerful engines.

The front bumper covered the rounded fenders, the lower portion of the lights was embedded into the bonnet, and the door handles were embedded into the door panels. Only the door hinges protruded slightly. Fender skirts covered the rear wheels.

The first prototype had a split windscreen, while most of the other prototypes had a single-piece windowscreen. At least one prototype experimented with reducing drag principles through its three-piece windscreen. The large centerpiece of glass was flanked on either side by two smaller pieces which were angled rearward and integrated into the sides of the body. This was the most common configuration for the production T77s.

In the back was a continuously sloping form devoid of a rear window, limiting rear visibility. Only slits in the sheet metal allowed for limited rearward viewing. The rear fin went beyond mere decoration, as it was intended to increase lateral stability under high speeds. Later Tatra T77 examples had a widened rear portion of the body, with the rear fenders and door hinges now embedded into the bodywork. Transverse inlets now funneled air to the engine compartment.

The streamlined Tatra T77 and T77a were futuristic, bold, and revolutionary. It had a low-to-the-ground appearance with a shape that favored a reduction in drag, maximum efficiency, and high-speed performance.

The Tatra T77a

The Tatra T77a was introduced in 1935 and was equipped with a larger, 3.4-liter (207 cubic-inch) V8 engine which had its bore increased from 75 to 80 mm. Producing 75 horsepower, the top speed increased from 145 km/h to 150 km/h. Styling updates were minimal, with the most visual change being the addition of a third headlight. This central headlight did not move with the front wheels, but it did use an electromagnetic system enabling the reflector to move to illuminate the curb.

The Tatra T77 would inspire future design, most prominently being the German People's car (the Volkswagen Beetle), but unlike the 'bug,' it was a luxurious, hand-built automobile built in limited quantities.

by Dan Vaughan

Sedan
Chassis number: 23014

This Tatra T77 is the ninth production chassis completed and it is believed to have been purchased new by Count Jaromír Egon Czernin-Morzin and used in a tour of the Italian Alps in 1935. The Count retained the car until 1936, and much of the history that immediately followed is not known. It is believed that the car was used until the mid-1970s, after which it (is believed) was parked in a barn in Slovakia. A German enthusiast purchased the Tatra in 2005 and exhibited it at the Essen Classic Motor Show the following year. The current caretaker purchased the Tatra in 2007 and had it shipped to the United States. A no-expense-spared restoration began in 2012.

During the restoration, the factory-installed sunroof was replaced with a solid roof, and new front and rear bumpers were fabricated. The dark blue exterior was complimented by a period-correct gray leather interior. Ivory-colored instrumentation is set into a dashboard trimmed in walnut veneer. The air-cooled V8 engine was rebuilt and a new-old-stock carburetor was sourced from the Czech Republic.

The restoration consumed a decade and relied on experts both within the United States and abroad, with total costs exceeding $1 million.

by Dan Vaughan

Named after the Tatra Mountains, Tatra was a vehicle manufacturer in Koprivnic, Czech Republic that was founded in 1850. Originally beginning as a wagon and carriage manufacturer, Tatra produced its first motorcar in 1897 in Central Europe, the President. This was the first passenger vehicle in Central Europe. Tatra's specialty lay in luxury vehicles of a technically advanced nature.

On March 5th, 1934 the Tatra 77 was introduced to the press at the Prague Auto Salon. The Tatra 77 was a sensation as it was the world's first serially produced an aerodynamic car with a rear-engined air-cooled layout. The T77 overtook the world's motor car industry by several decades.

Following the completion of the two V570 prototypes, the Tatra team decided that a new aerodynamic car would only be an additional model. This new vehicle was aimed at the top of the automobile market and would be marketed at a very limited production rate.

This larger and more luxurious car was the top priority for Ledwinka's design team and all present development of the V570 was halted. The Tatra T77 was based on the 1933 V570 prototype and used it as a study model. The design team was attempting to keep abreast of the latest technology, architecture and visual arts. The T77 was designed with the goal of being fast, silent and stable and as a reflection of modern aerodynamic research.

The design team led by Austrian engineer Hans Ledwinka and his son Erich, believed that the introduction of an air-cooled rear-mounted engine would reduce efficiency loss in the driveshaft and noise and vibration that was caused by the driveshaft. The lack of a drive shaft would mean that the passenger compartment would become more comfortable as there would be no central floor tunnel. Passengers could now sit lower and more forward of the rear axle. The inter-axle weight was now evenly distributed which resulted in a lower center of gravity. The front of the vehicle was shortened while the engine mounted in the rear meant that the tail was extended as long as possible.

Tested extensively by Tatra engineers, the first prototype T77 was only a pre-production prototype though Tatra did produce a brochure for this vehicle. The brochure included photos, descriptions, and technical specifications. This vehicle was equipped with a rear-mounted air-cooled 90 degree V8 engine that had a cylinder capacity of 2970 cc and a power output of 60 hp at 3500 RPM. The T77 had an impressive drag coefficient of 0.212.

The Tatra T777 was both massive and roomy, with seating for six. There was plenty of luggage space, housed above the rear suspension and in the nose, where the spare tires and battery resided.

The engine power was propelled to the driven rear wheels by means of a four-speed gearbox that was bolted together with the engine and the axle drive as one big monoblock. Housing the gear-change rods, cables, and fuel lines, the monoblock was enclosed by the forked welded box frame of the chassis and could be easily removed from the car for repairs and changing parts.

The T77 was slowly produced on a very small scale, with the vehicles behind almost completely hand-built. These vehicles featured leather upholstery and a well equipped interior and were aimed at the top of the automobile market. In a unique twist, a few models had the steering wheel placed in the center of the dashboard. Other T77's had the steering wheel on the right hand side. The front seat passengers were seated on either side of the driver, and the seats placed slightly back.

The T77A was introduced in 1935. The updated and improved model had an increased V8 capacity of 3.4 liters. The increase was made possibly by enlarging the bore diameter from 75 to 80mm. The output was now increased to 75jp and the maximum speed to 150kph. Three headlamps were now added to the front and the central unit was linked to the steering wheel on several models. Now three different directions of the headlight were possible. The lamp was now capable of being turned with the wheel. Several models were equipped with canvas Webasto roofs.

The driving characteristics of the revised Tatra T77 were vastly improved along with the styling being updated nicely.

In between 1933 and 1938 a total of 255 vehicles were produced of the type T77 and the T77a. Since all models were hand built, no two were exactly alike.

by Jessican Donaldson