This cement mass is heightened at many places so as to make platforms and supports for huts.
Passengers and goods are generally in different and sometimes in distant positions, the place selected for each being that which is most convenient for the traffic. The passenger station abuts on the main line, or, at termini, forms the natural terminus, at a place as near as can conveniently be obtained to the centre of the population which constitutes the passenger traffic; and preferably its platforms should be at or near the ground level, for convenience of access.
In order to keep down the expense of shunting the empty trains and engines to and from the platforms the carriage and locomotive depots should be as near the passenger station as possible; but often the price of land renders it impracticable to locate them in the immediate vicinity and they are to be found at a distance of several miles.
Many large stations, however, are of a mixed type, and the offices are arranged in a fork between two or more series of platforms, or partly at the end and partly on one side.
When the railway lies below the surface level the bulk of the offices are often placed on a bridge spanning the lines, access being given to the platforms by staircases or lifts, and similarly when the railway is at a high level the offices may be arranged under the lines.