I. CONSTRUCTION AND EQUIPMENT.

CONSTRUCTION.

General Remarks.-In this and other countries the drivers of carts, waggons, and other vehicles, almost invariably endeavour to let them run on the tram rails, because the traction is easier for the horses; but unless the rails are several inches in width, and thus able to accommodate the varying gauges of these vehicles, the drivers cannot succeed in keeping all the wheels fairly on the rails for many yards successively. As it is, the wheels run sometimes on the rail, sometimes on the adjoining paving, and sometimes partly on both rail and paving. Moreover, when it is remembered that carts and waggons are often without springs, and heavily laden, it is easy to understand that their constant jolting on or against the rails, or along the adjoining paving, causes the permanent way to be much shaken and loosened, and worse than all, causes the paving at the sides of the rails to be worn into holes and ruts. In this way not only is the wear and tear of the tramway immensely increased, but where the paving near the rails is worn into ruts the sides of the rails are of course exposed, and offer dangerous obstructions to light vehicles. Every effort should be made in designing the permanent way of a tramway to lessen these defects, and to reduce the excessive cost of repairs.

FIG. 1.

Permanent Way.-In the United States, rails with grooves (Fig. 1) have been tried, but generally condemned. The grooves must necessarily be small, so that ordinary carriage-wheels cannot enter them, and hence they soon become clogged with dirt and stones. This necessitates the constant employment of men to clear the rails; but even then the friction is so great that it is estimated that, on an average, nearly a third more power is required to draw the cars along grooved rails than along rails without a groove, where the flanges of the wheels are free. For the same reason grooved rails add greatly to the destruction of the wheels, and are also frequently the cause of the cars "jumping" off the rails. Grooved rails also add to the difficulty of preserving the gauge, because when the grooves are not quite clear they bind the car-wheels, and the latter in their turn thrust out the rails laterally.

İn many places in the United States tram rails are used with broad horizontal flanges, from 3 to 5 inches in width (see Figs. 3 and 4), so that vehicles without flanged wheels can run on them easily. Where there is a heavy cart and waggon traffic, it is more economical to make this provision in the first instance, at an increased outlay, than to adopt a system of permanent way which tempts drivers to try to keep on the rails, but which practically results in some of the wheels being run not on, but close to, the rails.

In Philadelphia, the city authorities require all the rails to be of a uniform section, with broad horizontal

I. CONSTRUCTION AND EQUIPMENT.

CONSTRUCTION.

General Remarks.-In this and other countries the drivers of carts, waggons, and other vehicles, almost invariably endeavour to let them run on the tram rails, because the traction is easier for the horses; but unless the rails are several inches in width, and thus able to accommodate the varying gauges of these vehicles, the drivers cannot succeed in keeping all the wheels fairly on the rails for many yards successively. As it is, the wheels run sometimes on the rail, sometimes on the adjoining paving, and sometimes partly on both rail and paving. Moreover, when it is remembered that carts and waggons are often without springs, and heavily laden, it is easy to understand that their constant jolting on or against the rails, or along the adjoining paving, causes the permanent way to be much shaken and loosened, and worse than all, causes the paving at the sides of the rails to be worn into holes and ruts. In this way not only is the wear and tear of the tramway immensely increased, but where the paving near the rails is worn into ruts the sides of the rails are of course exposed, and offer dangerous obstructions to light vehicles. Every effort should be made in designing the permanent way of a tramway to lessen these defects, and to reduce the excessive cost of repairs.

FIG. 1.

Permanent Way.-In the United States, rails with grooves (Fig. 1) have been tried, but generally condemned. The grooves must necessarily be small, so that ordinary carriage-wheels cannot enter them, and hence they soon become clogged with dirt and stones. This necessitates the constant employment of men to clear the rails; but even then the friction is so great that it is estimated that, on an average, nearly a third more power is required to draw the cars along grooved rails than along rails without a groove, where the flanges of the wheels are free. For the same reason grooved rails add greatly to the destruction of the wheels, and are also frequently the cause of the cars "jumping" off the rails. Grooved rails also add to the difficulty of preserving the gauge, because when the grooves are not quite clear they bind the car-wheels, and the latter in their turn thrust out the rails laterally.

In many places in the United States tram rails are used with broad horizontal flanges, from 3 to 5 inches in width (see Figs. 3 and 4), so that vehicles without flanged wheels can run on them easily. Where there is a heavy cart and waggon traffic, it is more economical to make this provision in the first instance, at an increased outlay, than to adopt a system of permanent way which tempts drivers to try to keep on the rails, but which practically results in some of the wheels being run not on, but close to, the rails.

In Philadelphia, the city authorities require all the rails to be of a uniform section, with broad horizontal

flanges, and the gauge to be 5' 2", in order that vehicles of all kinds may have a smooth surface to run on, and be more easily kept on the track. By this means a more uniform direction is given to the general traffic of the streets.

FIG. 2.

A rail known as the crescent rail (Fig. 2) has been much used. It is cheap, and in outlying districts it has advantages; but there is no protection for the flanges of the car-wheels, so that they constantly ride on stones and other obstructions, and where there is much traffic this adds greatly to the wear and tear of the wheels. Sections (Figs. 3 and 4) have been extensively used in New York, Philadelphia, New Orleans, and many of

the large American cities; but these rails have a tendency to tilt, as in sketch (Fig. 5). This is chiefly owing to the unequal loading of these rails, for the carwheels run on one side only of the rails, and the whole weight of the car is therefore brought on to that one side of the rails. This causes the timber sleepers to be more compressed and worn under the side of the rail which is most used, and it also causes an excessive strain on the fastenings of the rails.