Citroën C10: Ladybird from the Future

André Lefébvre is a legend in French automotive circles. An aeronautical engineer by training, he worked with Gabriel Voisin on both aeroplanes and cars before a brief stint at Renault then finally moved to Citroën, where he helped engineer some of the greatest cars in French history. His projects included the Citroën Traction Avant, the Deux Chevaux, the DS, and the HY, the corrugated panel delivery truck that was a staple of delivery businesses in France for a generation.

One project that is often overlooked when reviewing the CV of Lefébvre (above), though, is his work on a forward-looking family car, one that would project Citroën into the future and establish its advanced technology credentials.

The project began in 1953 as an attempt to broaden Citroën’s product line and to create a car that would cruise the new generation of toll roads that were being planned in France at the time. The first of these, the Autoroute de l’Ouest (now part of A13) that ran between Paris (Porte de Saint-Cloud)) and Rouen was completed in 1946 and opened a convenient route for weekend trips to the beaches of Normandy. By the 1950s the national government was working with regional authorities to establish a national network of modern highways, and Citroën wanted to have a modern car and a modern image for this new era of French motoring.

In our current era of multiple product lines and subcategories, it is hard to believe that Citroën sold only two cars in the early 1950s – the venerable Traction Avant and the rough-and-tumble Deux Chevaux. The DS was just over the horizon (and already undergoing secret testing in the south of France), but Lefébvre and others at Citroën recognized the need for a mid-range family car; affordable, but also appropriate for motorway driving.

Lefébvre organized a team and drew up a brief for the car. It was to have ample room for four passengers and their luggage. It was to be front-engined, front-wheel drive and be able to cruise at 100kph, while being economical on petrol (prescient, as the Suez Crisis was just around the corner). Costs were to be kept low enough to be in reach of a family who could not afford the forthcoming DS but still wanted to drive a piece of the future.

Lefébvre’s team featured some of Citroën’s all-star engineering luminaries. Andre Estaque would be responsible for the structure, placement of the engine, and transmission and Alain Roche would be responsible for the suspension and handling. Flaminio Bertoni, the legendary Citroën designer, was considered for the project, but Lefébvre wanted to hold this design close, so he, along with his engineers, personally took charge of the design. Besides, the project, destined to be known as the C series, would be a culmination of Lefébvre’s 35 years of automotive and aeronautical expertise, and as we will see, would be a swan song for Lefébvre’s career.

The design that emerged from an intense planning process was a four-passenger teardrop-shaped car that soon acquired the nickname ‘Coccinelle’ (ladybird or ladybug) or sometimes ‘Gotte d’Eau’ (water drop). Aerodynamics played a major role in the design, and the coefficient of drag was just 0.258 – astonishing in an era before computer analysis. The streamlined body was built of fibreglass and placed over a lightweight metal frame, while the glazing was constructed of Perspex (plexiglass). The first prototypes had enormous gullwing doors, but they proved heavy and awkward. Later prototypes had a lightweight gullwing upper door and more traditional half-doors at the base.

The underside of the car was covered with a sheet of duralumin (AU2G) with cast elements for reinforcement and for suspension supports. Connections between these elements, which would have, at the time, involved complicated preparations before welding, were instead glued with Rédox, an industrial epoxy. A hydropneumatic suspension was employed at both front and rear.

The engine (a 425cc flat twin adopted from the Deux Chevaux) and transmission were placed between and partially underneath the two front seats. The rear seat was positioned slightly lower than the front and behind this was a space for luggage or a child seat. The lightweight Perspex allowed for a generous glazing area, with no real blind spots for the driver. The Perspex was easily scratched, however, so windscreen wipers were eliminated. The windscreen could, instead, be lowered a few centimetres to give the driver a direct view of the road ahead. The aerodynamics of the windscreen supposedly deflected water and snow up and over this part of the windscreen. Testing on a track proved the concept worked, although no tests in real world conditions were ever reported.

The cabin of the C was minimalist, to say the least; creature comforts were not a priority. Seats were minimal and lightweight, more like patio furniture than a traditional car seat. The steering wheel was of single-spoke construction, previewing the DS and a future design cue of Citroën interiors. The IP was simple and very utilitarian – a finished version, such as it was, did not appear until the C10.

It is almost impossible to look at the C10 and not compare it to Buckminster Fuller’s Dymaxion car (above) of two decades prior. Though no documentation shows that the Citroën team referenced the Dymaxion, LeFébvre must have known about the car – and also its trials and tribulations on the road. That car, also teardrop-shaped and with similar aerodynamics (as you can see from the schematic below), was much larger, though, and powered by a Ford V8. And while both cars had front-wheel drive, Fuller’s car had a rear-mounted engine, three wheels instead of four – and the rear wheel was the steering one, making for an incredibly tight turning circle and treacherous handling at speed (one of the Dymaxion prototypes crashed at high speed killing a driver).

But despite the differences, the C series also had handling problems at first. All that weight over the front wheels, plus a couple of passengers, made for awkward weight distribution and thence terminal understeer, a problem that would lead to a crash of one of the C prototypes. The narrow track in the rear did not help either, although it was not as drastic as the Dymaxion. Unlike Fuller’s car, however, the engineers assigned to the C project improved the suspension and handling with each prototype.

And then disaster struck. Lefébvre suffered a stroke and sustained a lasting paralysis on his right side. He would be forced to retire from Citroën and spend the rest of his life trying to recover. He trained himself to use his left hand and still did freelance design work, but his days in the automotive world were behind him. Meanwhile, his team soldiered on, completed the C10 and tested it, confirming its much-improved handling and roadworthiness. But without Lefébvre’s strong voice supporting the project, Citroën’s Board would ultimately choose a safer option, a Bertoni-designed supermini that would be known as the Ami 6 (or 3CV), a car that would become a very strong seller in France.

The C10 and its older siblings were not concepts in the sense that we know them now; they were internally-focused test platforms and proof-of-concept prototypes for a planned production car to come. They were not meant for auto shows or public viewing, and their rough edges show. Still, they are remarkable to see some 60 years later, for what they are and what they attempted to accomplish.

Like so many other concept cars, the C10 leaves us asking ‘what if..?’. Advanced materials, innovative engineering and aerodynamics, ultralight construction (the C10 only weighed 382kg), creative packaging – all these seem the perfect recipe for automotive innovation. But, as Citroën legends Flaminio Bertoni and Robert Opron would remind us, a bit of styling is always a very good thing as well.