How are railroads constructed?
Railroads, like people begin their day in bed. Laying a proper bed for tracks is essential, because that is what gives stability to the rails. The bed consists of broken/crushed rock which is pressed into the soil, then more is added, usually of smaller size until finally a wide and heavy base is in place. A careful measurement is made in advance, using a level, called a transit, to be sure the intended direction is clear, and then the bed is made. Dips and holes are all filed so that, when finished, the entire length of the bed is as level across the top as possible. Large blocks of wood, called ties, are prepared in advance. The preparation consists of chemical treatment to keep them free from molds and insects. This chemical used to be creosote, but modern chemical mixtures last longer, and are more effective than creosote. The ties do two jobs: they hold the rails in place and they act to spread the weight of the trains that will come later. The steel rails are long and thin and wo
