FEATURE - 1922 Citroën Kegresse Auto-chenille

Words: Mike Ryan

Photos: Citroën

In the early years of the 20th Century, crossing the Sahara Desert was achievable, but incredibly time consuming. The sole mode of transport available was the camel, which took around six months to complete the 3,000+km journey from north to south, with the meandering route determined by the proximity of wells and oases that dotted the region.

France's colonial possessions in Africa back then covered both ends of the desert – Algeria in the north and French Sudan and French West Africa (now Mali, Burkina Faso, Upper Volta and the Ivory Coast) in the south. Linking the two required a journey by ship around the Atlantic coast, or the aforementioned camel train. Both were long and arduous.

A rail link across the desert was considered possible, but such a link wasn’t felt necessary until World War I, when the demand for natural resources became urgent. When the war ended, the idea didn’t, leading to one of the great expeditions of the age.

Automobile Reconnaissance

Trade fuelled the idea of constructing a rail line across the Sahara, but it was felt such a line could be used for tourism purposes, too. However, the region was still dangerous back then, and not just because of the climate.

Hostile Touareg tribesmen had been raiding camel trains for centuries and continued the tradition against the French in the colonial era, requiring a series of forts to be established across northern Sahara. Further south, the lack of water meant those who travelled the region were on their own and could not call on French military support.

With such challenges in mind, the idea of a rail line seemed a little fanciful, not just from a logistics point of view, but also in terms of maintenance and protection. Nevertheless, the French felt such a railway could be beneficial, as well as demonstrating their power in the region.

To survey such a route, automobiles were used, aided by aircraft. But the danger of even these operations couldn’t be underestimated. In 1918, a French military expedition drove around 200kms into the heart of the Sahara, but lost 18 lives at the hands of the Touareg before turning back. A second expedition in 1920 saw 17 lives lost.

Conventional cars and trucks had been used on both occasions and found the going tough in the sand: the 1920 expedition fielded no fewer than 32 Fiat trucks, three-quarters of which broke down or were abandoned on the journey south, with only two or three making it back to the expedition’s start point. A different type of vehicle was needed, and a young automobile ‘start-up’ company found it in an unlikely place.

From Snow to Sand

As a carmaker, Citroën had been established in 1919, and founder Andre Citroën, hungry for publicity, saw a Trans-Sahara expedition as an ideal promotional opportunity for his young company.

Citroën knew his ‘B2’ tourer wasn’t up to the task of crossing the desert in standard specification, so some major modifications were required, including one developed by a fellow Frenchman.

Adolphe Kegresse had been trained in engineering and put that training to use when he moved to Russia in 1905 to serve as Tsar Nicholas II’s chauffeur. The inability of conventional automobiles to travel across snow in Russian winters led Kegresse to develop a rubber caterpillar-track system that was lighter, more flexible and more effective than conventional metal caterpillar tracks, as snow didn’t stick to rubber. Kegresse perfected his system over a decade and a handful of cars in the Tsar’s Imperial Garage had been fitted with caterpillar tracks before the Russian Revolution saw Kegresse return to France.

Finding work with Citroën, Kegresse also found an enthusiast for his lightweight caterpillar track system. Andre Citroen saw the potential in the Kegresse system, developing it further for forestry and farm work, military applications, and most importantly, a way to cross the Sahara.

Famous Five

More than just reconnaissance vehicles for a future rail line, Citroën felt his Kegresse-equipped cars, dubbed ‘auto-chenilles’ (motorised caterpillars) could be a means of cross-desert transport in their own right, with applications in other unchartered regions around the world, too.

Backed by the French Government, serious work on a fleet of Citroën-Kegresse half-tracks got underway in 1921, with trials conducted in Algeria later that year. The base unit for these vehicles was the aforementioned B2; a light tourer powered by a 1.5-litre four-cylinder engine of just 20hp, driving the rear wheels through a three-speed manual gearbox. Quarter elliptic leaf spring suspension and rear-wheel-only brakes were typical for the period.

To this, the Kegresse caterpillar track system was added, along with a two-speed transfer case to enable ultra-slow crawling on sand. The cooling system was upgraded and purpose-built bodies fitted. In total, fifteen vehicles were built: five to take on the cross-Sahara expedition itself, with a further ten used to lay down dumps of fuel, spare parts and provisions. These dumps covered only part of the 3,200km route, though, with several stretches, including an 800km leg (almost the distance from Sydney to Melbourne) requiring the crews to be entirely self-sufficient. No radio equipment was carried for reasons of weight, but cinematic and still cameras to document the journey were included. Mindful of the dangers ahead, three of the vehicles would be fitted with machine guns and all the crews would be armed.

Choosing to start the expedition late in the year, when the desert heat was at its least ferocious, the five Citroën-Kegresse auto-chenilles – Golden Scarab, Flying Tortoise, Silver Crescent, Sacred Cow and Crawling Caterpillar – left Touggourt in northern Algeria on 17 December, 1922, for the 3,200km journey to Timbuktu. The goal was to cross the Sahara in 20 days.

Across the Sands

Leading the expedition was Georges-Marie Haardt, Citroën’s vice president and managing director, with the rest of the 11-man team made up of experienced explorers, a geographer, interpreter and five mechanics, who would also be the main drivers. Flossie, a Sealyham Terrier, was the team’s mascot.

The sand proved to be tough, while outcrops of rock battered the cars, too, putting the expedition behind schedule and exhausting the drivers, meaning the first rest period at In Salah, after five days and about a quarter of the total distance, was welcomed.

Departing In Salah on Christmas Eve, 1922, the five auto-chenilles faced their biggest test – an 800km stretch with only what they carried to get them through. Sand and flat plains gave way to the Gorges of Arrak, which threatened to trip the cars up with its mix of steep rock canyons and loose sand.

Further challenges were to come when the Citroën expedition cleared the Hoggar mountains and entered the Tanezrouft – an area of lifeless desert with no wells or oases for 500kms. The difficulties of this section were compounded by a sandstorm on 30 December that lasted most of the day.

By New Years Eve, 1922, the worst of the route had been cleared, but the team still had almost 900km ahead of them, as well as the kind of high humidity they hadn’t encountered in the desert.

Throughout this, the Citroën-Kegresse half-tracks proved to be particularly durable. Some parts broke and overheating was a constant threat, as was losing traction and tipping the vehicles over, but the maladies that had ended previous expeditions were eliminated by the overall durability of the half-track vehicles and their suitability to the conditions, as well as the Citroën team’s preparedness. 

By 4 January 1923, the sand and rocky plains gave way to grassland as the expedition entered the Sudan. On the same day, a grass fire threatened to end the expedition and forced the party to separate for a period.

On 7 January, 1923, the Citroën expedition rolled into the finish-point at Timbuktu, a day behind schedule, but with a full complement of men and cars – the first crossing of the Sahara by a motorised vehicle.

That was intended to be the end of the adventure, but the Citroëns had proven so suitable for the conditions that they were driven all the way back to the starting point at Touggourt a month later.

Upon their return to France, Haardt and his team were treated like conquering heroes, while orders for Citroën-Kegresse vehicles from governments and armies around the world more than covered the estimated £100,000 (more than AU$8 million in today’s money) Andre Citroën had spent on the journey.

Emboldened by the success of this expedition, Citroën next took part in an expedition travelling the length of Africa, the 20,000km Croisiere Noire, then another following the Silk Road route from Europe to China, the Croisiere Jaune, and a third across Canada, the Croisiere Blanche, all in auto-chenilles

The Citroën-Kegresse ‘Golden Scarab’ that was Haardt’s vehicle for the history-making Trans-Sahara expedition was retained by Citroen in the decades that followed. More recently, it was brought out of display for a special project.

Modern Tribute

In 2016, French students set about manufacturing a full and accurate replica of a C1922 Citroën-Kegresse auto-chenille, using modern CAD software and manufacturing techniques.

In all, 160 students from eleven French technical and engineering schools collaborated on the project, assisted by 40 teachers and supervisors, with support from industrial partners, led by Citroën.

With no original plans on file, students started by measuring every element of the Golden Scarab, recreating the car digitally, then using that digital model as the template for the manufacture of parts. The Kegresse caterpillar track system alone carries 1,203 individual pieces, which required thousands of hours of work.

After three years, 50,000 hours and more than 200,000 Euro (AU$320,000 approx.), the replica was completed early last year – just in time for Citroën’s centenary celebrations.

Back to the Sand

Earlier this year, Citroën announced plans to recreate the 1922-23 Trans-Sahara expedition with the vehicle pictured and a second Citroën-Kegresse. But this new expedition will be brought into the new millennium with a fleet of five modern electric Citroëns and a “crazy” Citroën concept also taking part.

Dubbed the ‘E.Pic Sahara’ drive, the new expedition is scheduled to kick off in Algeria in December, 2022, covering the same 3,200km distance and running for the same 21-day period as the original.