Societe Anonyme des Usines Renault, Billancourt (Seine), France
Advertisement for the Renault GP (click on image to enlarge)
The Renault company was founded in 1898 by Louis Renault and his brothers, Marcel and Fernand, to build automobiles. Renault's first car was the Voiturette, a name which was applied to several different models over the next five years. The range soon expanded to include buses, taxis and commercial vehicles, and with the onset of the First World War, Renault's production facilities were turned over to the manufacture of ammunition, aeroplanes and most significantly, tanks. The Renault FT-17 light tank was the first to feature a gun in a fully-rotating turret and established the layout of the driver at the front and engine in the rear. At least three thousand of these tanks were built by Renault, and the experience gained in mass-production of tracked vehicles led them to consider production of an agricultural crawler as early as 1917.
It is often stated that Renault's first agricultural tractor, the Model GP crawler, was based on the design of their FT-17 tank, but this is not true. In fact, the basis for the GP seems to have been the American Cletrac Model R, and photos exist of a Cletrac in the Renault works that was evidently purchased for study purposes. The tracks on the early Renault GPs are almost identical to those on the Cletrac, but totally different to those on the FT-17 tank, and the GP had the engine at the front rather than at the rear! Mass production of the GP began in February 1919 on the same assembly lines used for building tanks, and continued for the next two years, with a total of 425 units built. The elegant curved bonnet of the GP reflected Renault's automobile heritage, while the sloping radiator positioned in the middle of the tractor was decidedly unconventional, but was essential for the novel method of cooling using a fan directly behind the engine.
The next distinct model of tractor to emerge was the HI in 1920. This crawler superficially resembled its predecessor, but featured numerous improvements to the track system, transmission and steering, as well as being offered in a gas-producer version. Production numbers were not that much higher than for the GP, but HI crawlers were exported to such diverse places as Russia, Australia and New Zealand. Following trials by the military authorities in December 1921, the HI was also approved for inclusion in a scheme whereby owners of these tractors received an incentive to allow their machines to be requisitioned for military purposes if necessary. As a result, the army had a guaranteed supply of tractors at their disposal, but did not need to purchase or store these tractors themselves. The first Renault wheeled tractor also appeared in 1920 - this was the HO, which was available both as an agricultural version on steel wheels and a road version on solid rubber tyres. Sales were very limited though, mainly because the tractor was too heavy, too expensive and used too much fuel, and Renault was forced to address these concerns when designing its next wheeled tractor, the Model PE.
Poster advertising the Renault PE (click on image to enlarge)
The legendary Renault PE was introduced in 1926 and represented the lighter, more efficient tractor that medium-sized French farms needed - Renault now had a tractor that could compete on equal terms with the American Fordson and IHC 10-20. More than 1800 were built before production ended on the eve of the Second World War, and a crawler version, the PO, was also offered. The PE initially used the same layout as its predecessor, with the radiator mounted behind the engine in the middle of the tractor and a large fan used to draw air into the fully-enclosed engine compartment; in front of the engine sat a huge air-cleaner to filter the air entering the carburettor. For the later PE1 and PE2 (as well as the PO crawler), however, Renault switched to a more conventional design, with the radiator in its more usual position at the front of the tractor, and this would be the pattern for all subsequent Renault tractors. The PE also formed the basis for the Model RK, which was almost identical in external appearance but used a two-cylinder semi-diesel engine in place of the PE's petrol power unit and was far less successful.
The 1930s saw Renault expand its range significantly with the introduction of the little 8hp Model YL (later AFD), the VY and AFXD diesel models and the AFMD/AFMH crawler with either a diesel engine or gas-producer unit; industrial versions of the wheeled models with pneumatic tyres were also offered. In the post-war period the company went on to develop the famous R3042 and its derivatives, with a choice of petrol or diesel engines, and the elegantly styled D-series. Renault established a reputation for quality that continues to this day, although since the purchase of Renault Agriculture by Claas in 2004, the familiar orange livery has been replaced by green and the tractors no longer carry the Renault name.
GP / GU (1919-1923)
The GP crawler used Renault's own design of four-cylinder petrol engine, a 95 x 160 mm (4.5 litre) side-valve that produced 20-30 hp at 1000 rpm. This was cooled by the thermosyphon method and lubricated by a gear-driven oil pump. Four forward speeds were provided and power was transmitted to the gearbox via a cone clutch, and then to the track sprockets via double reduction gears. The tracks were supported at the front by a strong leaf spring and the crawler was steered via band brakes on each track controlled by a T-bar. Early versions of the GP seem to have been fitted with 17.5 cm wide tracks, based heavily on the Cletrac R, while later tractors used 27.5 cm tracks (giving an overall width of around 1.7 m and length of 3.45 m). A limited number of crawlers were assigned the model designation "GU" - it is unclear exactly how these differed from the GP, but they may have had the wider tracks as standard. A total of 502 GP/GU crawlers were produced, and it is thought that just 33 of these were the GU version.
Renault HI crawlers at Camp CoŽtquidan, Brittany, France
The HI was very similar in appearance to the GP, but featured a U-frame chassis in place of the GP's channel-iron design. Early versions used basically the same engine as the GP, but this received various modifications during the production period so that the final version had a removable cylinder head and yielded 34 hp at 1200 rpm. The track system was strengthened with heavier track frames and an arching support for the upper track rollers that passed over the middle of the tractor; the steering was also improved by using metal multi-disc clutches to stop the tracks rather than the inefficient band brakes. Later versions of the HI featured a larger radiator with a water-bath air-cleaner mounted on top. A total of 610 HI crawlers were built and a number of these were fitted with a gas-producer unit mounted at the rear of the tractor.
(click on image to enlarge)
The Renault HO had the same general layout as its tracked counterparts, but was shorter, narrower and used a smaller engine. Initially this was a 95 x 120 mm headless side-valve unit producing 20 hp at 1100 rpm, but in April 1926 it was replaced with an 85 x 140 mm unit with removable cylinder head that yielded just 15 hp at 1700 rpm. Tractors with the earlier engine had a girder-type chassis, but this was replaced with a lighter design that allowed better access to the engine after the new power unit was fitted. A three-speed gearbox was used, as on the HI, giving speeds of between 3 and 10 km/h. Both agricultural and road versions were offered: the agricultural tractor had riveted sheet-steel spoked wheels at the rear and cast spoked ones at the front, while the road tractor had solid rubber tyres on disc-type wheels. Just 210 examples of the HO were built.
The PE was a 10-20 hp tractor that weighed just 1300 kg and used a similar engine to several of the company's highly successful cars. This was the 259-KZ, a four-cylinder 75 x 120 mm (2.1 litre) petrol unit with removable cylinder head that greatly reduced the fuel consumption compared with the HO. The radiator was now in a vertical position, but still initially located in the middle of the tractor. This all changed, however, with the introduction of the PE1 in 1931, when the radiator moved to the front of the tractor, and the same design was used for the PE2, which appeared in 1935. From 1928 a vineyard version of the PE was offered, which was narrower with smaller wheels all round and cast ones the front. Other variants included road versions on both solid and pneumatic tyres, as well as petrol/paraffin and gas-producer versions. Optional extras included a belt pulley, mudguards, towing hook, hydraulic lift and electric lights. A total of 1840 Renault PE tractors were produced in the different versions.
Renault RK with semi-diesel engine (click on image to enlarge)
The PO crawler used a similar engine to the PE, the side-valve Type 279, which had a bore and stroke of 100 mm and 160mm, respectively, and produced 40 hp at 1300 rpm. The PO was designed for heavy-duty work including forestry applications and was huge machine, weighing 4400 kg. It was the natural successor to the HI, but differed from it in quite a few respects. The radiator was now located at the front of the tractor and the two vertical springs for the tracks were now positioned directly below the engine rather than at the front of the chassis. The upper track roller was set further back towards the rear sprocket and the arching support was dispensed with; two separate hand levers were now used to control the track clutches. In all, 255 Renault PO tractors were produced.
The Renault RK used the same chassis and transmission as the PE, but used a two-cylinder semi-diesel engine that could burn cheaper, lower-grade fuels than the PE's petrol power unit. This engine was known as the Type 293 and was of a 'square' design with 130 x 130 mm bore and stroke, producing 20 hp at 1000 rpm. Before starting, the cylinder heads were heated with burners until they were hot enough for the fuel to combust spontaneously under compression; the engine could then be started and the fuel was injected into the cylinders at the correct time by an automatic pump. The RK underwent the same changes as the PE with regard to the position of the radiator, and was also available as a road version with the optional extras. Despite its ability to burn cheap fuel, the RK was heavier than the PE, offered no more power, and cost about 25% more - these factors combined probably explain why only 113 examples were built.