The initial production voiturette was a 3.5hp rear-engined model, known as the Type ‘D’ , which was replaced in 1900 by an upgraded Type ‘E’ version, albeit with the same engine. In November 1900, the Type ‘G1’ appeared with a 4.5hp engine, followed in 1901 by a variant known as the Type ‘G2’. The last rear-engined model was the Type ‘L’, which had an identical chassis to the Type ‘G’ Type, but was equipped with the more powerful 6hp engine that the company had initially installed in its front-engined models from November 1901.
The early versions had an open, lightweight, vis a vis style body, providing two side-by-side seats facing forward and a third seat in front facing to the rear, positioned on a tubular chassis that was supported on semi-elliptical springs at the front and, eventually, on three-quarter elliptical leaf springs to the rear. When the Type ‘G’ arrived at the end of 1901, it was offered with a range of body styles, including a four-seat tonneau, a phaeton, and a closed delivery van, in addition to the established vis a vis model. Many of the vis a vis models had a facility to convert the front seat to a forward-facing configuration with a folding footboard.
All of the models closely followed the pattern initially established by the Type ‘D’, and that itself owed a great deal to the configuration adopted for the tricycle. Those later tricycles with variable speeds, had the speed changing device adjacent to the engine, with the secondary shaft carrying the pinion that transmitted the drive to the crown wheel at one end. This layout was chosen for the Type ‘D’, and the design of its 3.5hp engine was essentially very similar to the 2.75hp engine installed in the later tricycles, complete with the identical ignition system attached to the half-time shaft of the engine. Early models were not equipped with a reverse gear, but many vehicles have had one retro-fitted.
The drive was taken through a 2-speed expanding clutch gearbox to a differential gear unit, mounted on the chassis midway between the two rear wheels. The drive to the rear wheels was transmitted from the differential unit by means of two universally-jointed half-shafts. The rack and pinion front wheel steering was of a construction referred to as the ‘Ackerman Type’, controlled by a two-handed lever on a vertical column. Below the steering lever there is a wheel that operates the clutches for the individual gears. Voiturettes have two contracting brakes: one on the differential gear, and one on the engine shaft, and each brake is operated by a separate pedal.
The voiturette provided comfort in convivial style for two or more passengers that a tricycle or a quadricycle could not, and it was perfectly capable of long journeys by night or day, added to which it also offered advantages in cost, operation and maintenance for owner/drivers that vehicles produced by other manufacturers did not. The presence of a light, high-speed petrol engine in a relatively lightweight body influenced many other manufacturers who adopted similar designs for their own vehicles.
Type D (80mm x 80mm engine with 34mm Inlet Valve)
Type ‘D’ has ball-bearing wheel hubs. There are no brakes on the rear wheels. The rear axle is unsprung, although ‘C’ springs were offered as an optional extra. The water-cooled cylinder is a single casting. Speed change is effected through a small wheel under the steering handlebar. There are two brakes: a pedal under the foot acts on the differential, and a pedal under the heel brakes a drum linked to the secondary shaft of the speed change.
Type E (80mm x 80mm engine with 34mm Inlet Valve)
Type ‘E’ has re-inforced ball-bearing wheel hubs. The ‘D’ Type’s secondary shaft brake has been replaced by two rear wheel brakes, activated by a lever mounted horizontally on the steering column; the same lever controls the clutch engagement of the two-speeds, and replaces the small wheel under the steering handlebar present in the ‘D’ Type. The heel pedal of the ‘D’ Type is no longer present. Three quarter elliptic springs are set between axle and the chassis.
Type G1 (84mm x 90mm engine with 34mm Inlet Valve)
Type G1 has Ball-bearing wheel hubs, and the larger 4.5hp engine. New to this model, and a staple of all future engines is the exhaust valve control, situated behind the steering column, that prevents some of the burnt gas escaping, thus reducing the size of the next charge, and so reduces engine output. There is a modified carburettor with the float and mixing chamber in the same casing, and the needle located vertically beneath. The gear-pump is of rectangular shape.
Type G2 (84mm x 90mm engine with 38mm Inlet Valve)
Within the official Type classification, there is only one ‘G’ Type, but the later examples have characteristics that set them apart, hence the ‘G2’ mark. The Type G2 models have plain bearing wheel hubs, of greater length, and a pronounced external bulge between the steel spokes, on which is a Stauffer greaser. The earlier rectangular gear-pump is replaced by a vane-type centrifugal pump in a circular bronze casing. The engine is mounted in the chassis on four straight bearer arms. The inlet valves are larger than the previous types.
Type L (90mm x 110mm engine with 38mm Inlet Valve)
The Type ‘L’ is identical to the Type G2 with the exception that it has the larger engine, with a bigger crankcase, requiring the bearer arms to be modified; they are no longer straight, but curved. Amongst voiturettes, curved bearer arms are only evident on Type ‘L’ vehicles
Single Cylinder Front Engine Vehicles
De Dion Bouton launched twelve single cylinder passenger vehicle models between the summer of 1901 and December 1904. Two of the early models: Type ‘H’ and ‘I’ are best considered as prototypes since only four models were produced. Apparently, they were quite different in appearance to the ‘J’ Type that appeared in November 1901 since they had vertical rather than raked steering columns, and their engines were the only single cylinder models with an oil pump.
The Type ‘J’ established the general silhouette and characteristics of all cars that followed: the engine was in front under a tapered ‘coal scuttle’ bonnet; the radiator was forward of the chassis and placed lower than it; the raked steering column was supported by two slender vertical columns that held the controls for ignition, carburation, and clutch. A handbrake operated a band brake on the rear wheels, and a steel drum on the secondary shaft, on which two cast iron jaws tightened. Transmission from engine to gearbox was by a shaft with Cardan joints. The crown wheel was driven by a bevel gear. Transmission from the differential to the wheels was by double-jointed shafts and wheels were driven by their outer sections by means of shafts passing through hollow hubs.
Despite the innovative overall design of the earliest front engine vehicles produced from the end of 1901, they did have many similarities with their rear-engined predecessors: many of the constituent parts are slightly modified variants that have been repositioned. The engine is fundamentally the same design, with a progressive increase in power output and efficiency. The gearbox retains its individual expanding clutches, and the rear transmission, water pump, and carburettor are thoroughly reminiscent of earlier produced components. The chassis throughout the period is of tubular construction, like the voiturette. The most significant change between models is the shape and design of the dumbirons and the springing adopted, especially at the front of the vehicle. It is this consistency of design that has led to a degree of confusion in the identification of the various models produced during the period.
In 1902 the De Dion Bouton Company made the decision to create two distinct categories of vehicles: light cars, and cars, for the 1903 season. The established layout of the components for both categories would be identical, but there would be differences in weight and power. The light cars, on the whole, would have smaller engines mated to twin speed gearboxes, and be lighter. They were designed to appeal to those individuals who did not wish to engage the services of a driver. The cars would comprise single and twin cylinder vehicles equipped with larger engines, three-speed gearboxes, and be capable of carrying more formal coachwork, with an appreciable weight difference.
The Type ‘J’ model specifications were considered by the Departement des Mines on the 21st November 1901 and received full Type Approval on the 28th of December of that year. Whilst there was sometimes a period of a few days between Type review and ‘sign off’ by the Chief Engineer of the Departement des Mines, this five-week period was unusually long.
The ‘J’ Type engine (90mm Cylinder bore and 110mm stroke) with 38mm inlet valve was the same 6hp unit that was employed in ‘L’ Type voiturette, available from May 1902. The engine has the exhaust outlet at the front beneath the spark plug. The centrifugal water pump is driven from the rear of the engine. The carburettor is situated along the nearside of the engine.
The steering pivots (kingpins) are of single diameter and cylindrical on the outside
It is a twin speed model with reverse, which is selected by a lever placed behind the driver’s right knee.
The ‘K’ Type vehicles had two variants. the Type ‘K1’ model specifications were considered by the Departement des Mines on the 15th January 1902 and received full Type Approval on the 1st of February that year.
The Type ‘K1’ is very similar in external appearance to the earlier ‘J’ Type in terms of wheelbase and track, and the front-end dumbirons. Under the bonnet there are a number of visible changes: the engine is larger in size (cylinder bore of 100mm and 110mm stroke), and with an increased power output of 8hp, and a larger inlet valve of 42mm. It retains the exhaust port at the front of the engine, in common with the ‘J’ Type, and the top bearer arms supporting the engine are straight, whereas in the ‘J’ Type they are slightly curved. The carburettor is positioned in front of the engine to the offside, whilst the water pump, smaller in size than the ones provided for the later models, runs off a pinion from the differential at the rear of the vehicle.
The pinions on the primary shaft and the crown wheel are both fabricated from bronze
The K2 model launched in May 1902 was essentially promoted as a long wheelbase car, and the wheelbase is longer than the Type K1 by 12 cms, albeit with the same track of 1.18m. The K2 bonnet is longer than its predecessor, and the two front springs on the earlier model have been replaced with four half springs. The front kingpins have a constant dimension and are cylindrical in appearance.
The cylinder bore of the engine of 100mm has been retained, but the stroke has been increased to 120mm, providing increased power. The inlet valve is 42mm. The Type ‘K1’ ebonite ignition plate with two terminals has been superseded by a metallic plate with one terminal, although this distinction may not be evident on extant vehicles. The exhaust port is now placed on the nearside of the engine, and an enlarged water pump is placed in front of the engine above the radiator, and both characteristics remain for all subsequent single cylinder models.
The primary pinions of the gear-change system and the crown wheel, that were made in bronze for the Type ‘K’1, are now fashioned from steel. The gearbox with its two forward and reverse gear remain unaltered from the previous model.
The Type ‘N’ light cars, sometimes referred to as the first “Popular”, and typically with two-seater coachwork, received Type Approval on June 18th 1902.
The vehicle is equipped with the same 6hp engine (cylinder bore of 90mm and stroke of 110mm) as the Type ‘J’, released six months previously. It has a 38mm inlet valve.
It has a twin speed gearbox without reverse, although an option existed for a three-speed gearbox. The transmission is similar to that of the ‘G’ Type voiturette, although with different ratios.
The front wheel kingpins have a stepped diameter. The brake on the secondary shaft of the gearbox only has one shoe, instead of the two opposing jaws of the other models
The driver only has one floor pedal
The Type ‘O’ was the first of the ‘heavier’ vehicles planned for 1903, and it received Type Approval on the 9th of September 1902. With a wheelbase of 1.92m, it had the longest wheelbase of any single cylinder vehicle made up to that point.
The ‘O’ Type has the same engine as the K2 model with its 100m cylinder bore and 120mm stroke, along with a 42mm inlet valve. The carburettor is placed forward of the engine on the nearside
The main distinguishing feature of the Type ‘O’ is the three speed and reverse gearbox, which was fitted as standard for the first time. The gearbox has identical dimensions to the K2 model but there are differences in detail: the diameter of the sliding pinion was increased, so that the pinion can mesh directly with second high-speed crown wheel to produce the first speed. This crown wheel, by engaging a rocking pinion, will also give the reverse. The reverse is operated by initially selecting a lever behind the driver’s right knee. The movement of the sliding pinion, facilitates the combination of first/second, second/top, and reverse gear, is by means of a locking lever on a three-notched quadrant, which is situated on the steering column beneath the steering wheel. This feature does not appear on Type ‘K’ vehicles. The Type ‘O’ gearbox also feature on the twin-cylinder Type W vehicles.
Between the locking lever and the steering wheel is an exhaust valve lifter controlled by a wooden knob, that has the effect of reducing the expulsion of exhaust gas, and thereby limiting the volume of air entering the system, which reduces engine power.
The chassis has four half springs at the front and three springs at the rear.
Rather unusually during this period of intense development of De Dion Bouton vehicles, the earlier Type ‘N’ remained in production for ten months, until it was replaced by the Type ‘Q’ which received Type approval on the 2nd April 1903. Even at this point the number of changes that were incorporated into the ‘Q’ Type, which remained in production until September 1904, were relatively modest.
This model, another of the ‘light cars’, continued with the same 6hp engine as previously (90mm cylinder bore and 110mm stroke) with the 38mm inlet valve.
The Type ‘Q’ vehicle was equipped with a reverse gear as standard. The control of the reverse is by means of a pedal placed under the driver’s right heel.
The Type ‘Q’ model has an oil tank mounted on the dashboard next to the coil box, along with a hand pump lubricator with a three-way valve that feeds the engine, gear box and back axle.
For braking, there is a metal shoe on the counter shaft, operated by a foot pedal, and two leather lined bands on the hubs of the driving wheels, operated by the side mounted handbrake.
For factory produced bodies of this type, splayed front mud guards were generally used.
The front wheel kingpins have a stepped diameter
The Type ‘R’, also in the ‘light car’ category, received Type Approval on the 30th March 1903, at the same time as that of the Type ‘Q’ model. There is very little to immediately distinguish the two models other than the ‘R’ Type has the larger cylinder bore of 100mm, but retains the 110mm stroke, generating a power output of 8hp. It carries the larger 42mm inlet valve.
The Type ‘R’ has the same gearbox as the Type ‘Q’; it has a pedal under the right heel to control reverse, as previously. The engine/gearbox shaft is mounted at the gearbox on two Cardan joints, and on a double fork joint at the engine end. The washers between the tips of the Cardan shafts and the hollow hubs of the rear wheels are in brass.
It has two springs in front and three to the rear. The front wheel kingpins have a stepped diameter. For this model the front wheels have 10 spokes rather than the 12 of earlier models.
Type Approval for the ‘V’ was granted on the 9th December 1903. This model effectively replaces the earlier Type ‘O’, and has an engine of the same capacity (100mm cylinder bore and 120mm stroke with a 42mm inlet valve), although the external design is slightly different in that the cast iron water jacket has a separate domed lid.
The shaft linking the engine to the gearbox is mounted in a new way: previously this shaft was mounted at the gearbox end on two Cardan joints, and on a double fork joint at the engine end; on this model, it is mounted on Cardan joints at both extremities. The brass washers between the tips of the cardan shafts, and the hollow hubs of the rear wheels, are replaced by ball bearing thrust blocks.
There are two springs in front, and the front wheel kingpins have a stepped diameter.
Type Approval was granted for the Type ‘Y’ model on the 11th October 1904. The vehicle was powered by the same 6hp unit (90mm cylinder bore and 110mm stroke) as the previous ‘Populaire’ models, although as with all 1904 single cylinder variants, the cylinder head now has a separate domed lid that sits on a gasket.
This model had three forward and a reverse gear.
Twin Cylinder Front-Engined Vehicles
The 12hp Type S model that received Type Approval on May 18th 1903. L. Baudry de Saunier, writing in La Locomotion, in 1903 acknowledged that whilst the Type S was a large vehicle, he emphasized that it was both lighter than its competitors, and built for speed and comfort. There was a market for larger vehicles, and De Dion Bouton had recognised this opportunity in providing a long wheel version for the 8hp Type V vehicle launched in December 1903. The Type S chassis was designed to accommodate substantial heavier coachwork than its predecessors, and with an overall engine capacity twice that of the Type V, it could do so at comparable speed.
The 10hp Type W model received Type Approval on September 10th 1903. Whilst the engine of the Type W was comparable to that of its 12hp predecessor in broad design terms, its chassis and gearbox were quite distinct. Three months after the initial Type W Type Approval Date, De Dion Bouton sought further approval for a revised version of the Type W, which was granted on December 14th 1903. The 1904 model of the Type W had at the outset a new pattern of engine, and later in 1904, a revised carburettor and ignition system was fitted.
The twin cylinder vehicles were designed to appeal to a very select but limited market. In February 1904, a Type ‘Q’ Two-seater bodied vehicle made in England would cost a customer £245 with additional costs of around £30 for a windscreen and other accessories. The cheapest English bodied Type ‘W’ vehicle was set at £465, which would increase once the extra items had been installed; a popular option was the Tonneau with a detachable top, which had a price tag of £540. If the purchaser were to select a Type ‘S’ Landaulet on a long frame chassis, the basic cost rose to £700, and with the essential accessories in place, a final cost of £800 was possible.
The substantial costs of the twin cylinder vehicles help to explain their limited production, and also the relative scarcity of extant vehicles. Their chassis dimensions and impressive power output made them attractive for conversion to taxis and goods vehicles once their early owners had replaced them. Subsequent heavy usage very likely led to their abandonment once worn out, thus further depleting the numbers of survivors.
Twin Cylinder Type S
The layout of the Type S chassis is similar to that of Types J, K, and O, with its straight tubular side rails, a pair of parallel rails for mounting the engine on, and the steering arm assembly positioned ahead of the front axle. At the front, there are four half springs, and at the rear there are long semi-elliptic springs over the back axle, shackle bolted to the main inverted transverse spring, reminiscent of the arrangement with Types J, K, and V.
With the S Type the bore of each cylinder is 100mm and the stroke is 110mm, equivalent to the dimensions of the K1 cylinder, launched at the end of 1901. The overall capacity is 1728cc. The inlet valve has a diameter of 42mm. The two cylinders are housed in a single casting from top to bottom, with a single flange at the base of the cylinder block. The bases of the cylinders have vertical ribs that are 5mm deep. Access to the tops of the cylinders is through two separate concave lids on the water jackets. A number of features that characterized the single cylinder models have been significantly changed. The internal flywheels have been replaced with a single external flywheel. The reliance on splash lubrication has been abandoned in favour of a gear pump that draws oil from the bottom of the crank chamber and forces it into the tank at the side of the cylinder from which it runs through the bearings of the motor.
The earlier ignition by trembler makes way for ignition by breaker. The Type S has a double-barrelled twin-jet carburettor.
The Type S has three forwards and one reverse gear. In similar fashion to the engine lubrication device, for the first time the Type S has a gear pump placed in the differential casing, which acts as an oil reservoir and lubricates all points in the gearbox, and ensures continuous oil circulation in the differential.
Twin Cylinder Type W
The Type W chassis had a tapered layout, wholly different from the Type S, and reminiscent of the design of the lighter Type N, Q, R (and subsequent Y) models. The engine is mounted on a ‘U’ shaped tube that is attached to the cross member behind the front axle. The steering arm assembly is positioned behind the front axle, a feature that when combined with the narrower front portion of the chassis, provides an appreciably tighter turning circle than the Type S.
The Type W10 hp twin cylinder engine shares many of the design characteristics of the larger Type S variant, including the water pump, external flywheel and lubrication mechanism, although on the Type W this has been further improved and the connecting rod bearings are fed with oil from inside by passages drilled in the crankshaft. It also has the same 42mm inlet valve. The Type W engine, however, has a smaller capacity; its cylinders were 90mm bore and 110mm stroke, giving a capacity of 1400cc. There were two variants of the 10hp twin cylinder engine. Whilst the capacity and internal design remained unchanged, with the first type, launched in September 1903, both cylinders were situated in a single cast housing, which was only joined at the top, and the bases were separate. This is quite different to the ‘S’ Type where the cylinder housing is one piece. With the second variant of the twin cylinder 10hp model, available from mid-December 1903, the two cylinders are joined along their entire height, as with the ‘S’ Type. There are several external visible distinctions between the Type S and the Type W: the former has separate lids on the water jackets, whilst the latter has one overall cover. The most distinctive feature of this second 10hp variant versus the Type S engine is the depth of the vertical ribbing on the bases of the cylinders. As previously mentioned, the ‘Type S engine has vertical ribs that are 5mm deep, and the Type W has vertical ribs that are 10mm deep.
The single blade ignition system that was first used with the Type S continued with the first and second variants, but in May 1904 it was replaced with a twin blade one. Early in 1904 a new carburettor was introduced that differed from the previous twin cylinder model. In this version, there is one single-barrelled float feed device that serves two jets that are controlled simultaneously and to the same extent at all times.
The ‘W’ Type gearbox provides for three forward speeds and reverse, but is quite different from that of the ‘S’ Type, in both size and construction, and virtually identical to that of the earlier ‘O’ Type, except that the ratios were somewhat modified and the plain rear bearing on the primary shaft was replaced by a ball bearing. There is no forced lubrication. The control of the sliding pinion and the reverse is new and unlike that of the Type O. Also, the clutch lever that was placed previously on the left of the steering, is on the right in this type, so that the driver has under his right hand all the controls for the clutch, gear change and drive.
Information for this section has been extracted from the following publication:
- De Dion Bouton, An Illustrated Guide to Type & Specification 1899-1904. Michael Edwards, Surrenden Press, 2016.