Tractive Resistances to a Motor Delivery Wagon on Different Roads and at Different Speeds

In this paper is given a complete report on an investigation of tractive resistances of urban roads to a motor delivery wagon eqtuipped with solid rubber tires. The ``tractive resistance'' as used in this paper, includes still-air resistance, but does not include wind resistance and the resistances internal to the truck. The test truck is fully described with its driving mechanism and the storage battery which supplied the motive power. The investigation involved test runs over definite lengths of road, at measured truck speeds, to determine the gross battery output during those runs; and laboratory tests to determine the overall efficiency of the truck between battery terminals and rear-wheel treads at speeds and loads corresponding to the road tests. The results included in the paper are (1) overall efficiency of truck mechanism and (2) tractive resistances of a number of typical urban roads. The components of tractive resistance for a typical road are also given.