Motor Road Transport For Commercial Purposes
(Liquid Fuel, Steam, Electricity)

80 MOTOR ROAD TRANSPORT known and yet has probably the greatest future before it, a brief summary of the chief constructional features may be useful. The principal parts of the chassis as differing from the petrol vehicle are three in number ; namely, the controller, the battery, and the motors. The electrical energy is conveyed from the battery to the controller, and thence to the motors, and thus transformed into mechanical energy. The heart of the chassis—the battery—is usually carried by a sub-frame which is siung from the side members of the main frame. This design has been found to be the most practical method, since it affords good weight distribution, accessibility, and the maximum of flat surface for floor space. Battery Types. The two types of battery which are most generally used in this country are a nickel-iron-oxide-alkali- accumulator, and the Ironclad-Exide p. tern, which is a lead-plate cell. There are, of course, other makes and types of accumulators, but these two are the best known in Great Britain. Each kind has its own particular advantages and disadvantages, and in practice is found to give satisfactory results with no great difference in regard to combined reliability and maintenance. The controller is fitted near the driver’s feet, either above or below the floor-boards, and this position allows for the simplest form of handling in operation— i.e., one lever. The design of the driving mechanism is dependent upon whether one motor or two are to be incorporated, and whether the drive is to be delivered to the front or back road wheels. If a single motor is fitted, a differential gear will be necessary. The drive from the motor to the countershaft is conveyed by an enclosed silent chain, and thence from the