Citroen Traction Avant
The Citroën Traction Avant was an innovative front wheel drive automobile produced by the French manufacturer Citroën. About 760,000 units were produced from 1934 to 1957.
The Traction Avant, French for "forward traction", was designed by André Lefèbvre and Flaminio Bertoni in late 1933 / early 1934. While not the first production front wheel drive car - Alvis built the 1928 FWD in the UK , Cord produced the L29 from 1929 to 1932 in the United States and DKW the F1 in 1931 in Germany - it was the world's first front wheel drive steel monocoque production car. Along with DKWs 1930s models, the Traction successfully pioneered front wheel drive on the European mass car market.
The Traction Avant's structure was an arc-welded monocoque (unitized body). Most other cars of the era were based on a separate frame (chassis) onto which the non-structural body ("coachwork") was built. Monocoque construction (also called Unit Body or "Unibody" in the US today) results in a lighter vehicle, and is now used for virtually all car construction, although body-on-frame construction is still suitable for larger vehicles such as trucks.
This method of construction was viewed with great suspicion in many quarters, with doubts about its strength. A type of crash test was developed, taking the form of driving the car off a cliff, to illustrate its great inherent resilience.
The novel design made the car seem very low-slung relative to its contemporaries — the Traction Avant always possessed a unique look, which went from appearing rakish in 1934 to familiar and somewhat old fashioned by 1955.
The suspension was very advanced for the car's era. The front wheels were independently sprung, using a torsion bar and wishbone suspension arrangement, where most contemporaries used live axle and cart-type leaf spring designs. The rear suspension was a simple steel beam axle and a Panhard rod, trailing arms and torsion bars attached to a 3-inch (76 mm) steel tube, which in turn was bolted to the "monocoque".
Since it was considerably lighter than "conventional" designs of the era, it was capable of 100 km/h (62 mph), and consumed gasoline / petrol only at the rate of 10 litres per 100 kilometres (28 mpg-imp; 24 mpg-US).
The original model, which was presented on 18 April 1934, was a small saloon with a 1,303 cc (79.5 cu in) engine. This model was called the 7A, which was succeeded in June 1934 by the 7B with a higher-power engine of 1,529 cc (93.3 cu in). The 7B in turn, was succeeded in October 1934 by the 7C with an even higher-output 1,628 cc (99.3 cu in) engine. Later models were the 11 (launched in November 1934), which had a 1,911 cc (116.6 cu in) four-cylinder engine, and the 15 (launched in 1938), with a 2,867 cc (175.0 cu in) six. The numbers refer to the French fiscal horsepower rating, or CV. The 11 was an 11 CV, but curiously the 15 was actually 16 CV. The 11 was built in two versions, the 11L ("légère", or "light"), which was the same size as the 7 CV, and the normal model 11, which had a longer wheelbase and wider tread.
Citroën planned two variants that never entered production, since there was not enough funding available to develop them, except as running prototype vehicles. One was an automatic transmission-equipped model, based on the Sensaud de Lavaud automatic transmission, the other a 22 CV model with a 3.8 l V8. The transmission (which was actually originally designed for the Citroen) was a "gearless" automatic, using the torque-converter alone to match engine revolutions to the drivetrain revolutions, much like the Dynaflow Transmission introduced later in the USA. The car was supposed to have a less spartan interior than the other Traction Avant's and it was to feature Citroën's own new V8 engine. About twenty prototypes were made, but when the project was canceled in 1935 due to Michelin's takeover; they were probably all destroyed.
In addition to the 4-door body, the car was also produced as a 2-door coupé with a rumble seat, as a convertible and as an extended length Familial model with three rows of seats. There was even a hatchback-type Commerciale variant, in 1939, well ahead of its time, in which the tailgate was in two halves, the lower of which carried the spare wheel with the upper opening up to roof level. A one-piece top-hinged tailgate was introduced when the Commerciale resumed production in 1954 after being suspended during World War II.
Left-hand drive versions were built in Paris, France and Forest, Belgium, and right-hand drive cars in Slough, United Kingdom. The Slough version of the 11L was called the Light Fifteen and the long wheelbase 11 was called the Big Fifteen. This confusing terminology referred to the British fiscal tax rating of the time, which was higher than the French, so the 11CV engine was 15HP in England. The 15CV model was called "Big Six" in reference to its 6 cylinder engine. They were equipped with the leather seats and wooden dashboards popular in the UK, had a 12-volt electrical system and were distinguished by a different radiator grille and different bumpers. Some models also had a sliding sunroof.
The Traction Avant used a longitudinal, front wheel drive layout, with the engine set well within the wheelbase, resulting in a very favourable weight distribution, aiding the car's advanced handling characteristics. The gearbox was placed at the front of the vehicle with the engine behind it and the differential between them, a layout shared with the later Renault 4 and first generation Renault 5 but the opposite way round to many longitudinal front-drive cars, such as the Saab 96 and Renault 18 range and most Audi models. The gear change was set in the dashboard, with the lever protruding through a vertical, H-shaped gate. Because this vertical orientation could have resulted in the car dropping out of gear when the lever was in the upper positions (i.e. second or reverse gears), the gear shift mechanism was locked when the mechanical clutch was engaged and released when the clutch pedal was depressed. The result of this layout, along with pendant pedals, umbrella-type handbrake control and front bench seats, was a very spacious interior, with a flat and unobstructed floor. The low-slung arrangement also eliminated the need for running boards to step into or out of the vehicle. These features made them ideal for use as limousines and taxi cabs, and they were quite popular among drivers and passengers alike.
A 1,911 cc (116.6 cu in) Light Fifteen tested by the British magazine The Motor in 1951 had a top speed of 72.6 mph (116.8 km/h) and could accelerate from 0-60 mph (97 km/h) in 29.7 seconds. A fuel consumption of 25.2 miles per imperial gallon (11.2 L/100 km; 21.0 mpg-US) was recorded. The test car cost £812 including taxes.
A 2,866 cc (174.9 cu in) six cylinder model was tested by the same magazine in 1954 and for this car the top speed found was 81.1 mph (130.5 km/h), acceleration from 0-60 mph (97 km/h) 21.2 seconds and fuel consumption 18.6 miles per imperial gallon (15.2 L/100 km; 15.5 mpg-US). The test car cost £1349 including taxes.
The development costs of the Traction Avant, combined with the redevelopment of its factory, were very high and Citroën declared bankruptcy in late 1934. The largest creditor was Michelin, who then owned Citroën from 1934 until 1976. Under Michelin, Citroën was run as a research laboratory, a test bed for their radial tires and new automotive technologies.
In 1954 Citroën's experiments with hydropneumatic technology produced its first result, the "15H"—a variant of the 6-cylinder model 15 with a self-leveling, height-adjustable rear suspension, a field trial for the revolutionary DS released the following year.
Directly after the introduction of the Citroën ID, a simplified and more competitively priced version of the still revolutionary DS, production of the Traction Avant ended in July 1957. Over 23 years, 759,111 had been built, including 26,400 assembled in Slough in England, 31,750 assembled in Forest near Brussels and 1,823 assembled at Cologne in Germany. The total reflects the production stoppage during World War II.
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