Chapter 8

The Decauville Car

This car, made by the Société Nouvelle des Etablissements Decauville, Ainé, France, at one time appeared likely to be extremely popular, as the price was low, and the machinery is fairly simple. It is shown in fig. 25, and a photograph is given in fig. 26.

It consists of a double cylinder, high-speed engine, very similar to the engine of the motor tricycle described in a previous chapter. The cylinders have ribs for cooling cast round them, but in some of the later cars water-cooling is adopted. On the end of the crankshaft is the fly-wheel, and in this is the inner cone of a friction clutch by which another shaft, which may be considered as an extension of the crankshaft, is put in motion. This shaft carries two different size spur wheels, which are made to gear with two other wheels on a second motion-shaft, the spur wheels on the first-named shaft being free to slide laterally on their shaft, so that either wheel is made to gear with its fellow at pleasure of the driver. To change speed, the clutch in the face of the fly-wheel is released by the driver depressing a pedal; then the spur wheels are shifted on their shaft till the one required gears with its fellow, and the friction clutch is driven home and the engine drives the car.  A bevel pinion on the end of the last-named shaft gears into a bevel wheel on the main axle. On the main axle is the differential gear, and also the brakes. One of the chief features of this car is the small hand wheel at the side, so that the driver can start his engine without leaving his seat. The ignition is electric, two coils, one for each cylinder and accumulator, being used. There are no springs to the hind axle, the engine and its gearing being rigidly fixed to the framing. An inverted spring under the forecarriage allows a fair amount of up and down motion to the steering wheels. The tyres are pneumatic. In the writer’s opinion the chief objection to this car is the noise made by the gearing. The car has been considerably improved since it was first introduced.