To maintain the gauge. This is more or less the main purpose of the sleeper; if the rails just sat atop them they'd be effectively worthless.
The width apart of rail tracks are set to the gauge of the trains and carriages that are allowed to run on those tracks. They are kept in position by wooden sleepers, though concrete sleepers are often used nowadays.
To reduce the pressure exerted by train
to reduce the pressure exerted by the train
When sleepers are placed below the rails, the area of cross-section is increased. We know pressure= Force/Area. When the trains run on the rails, the pressure is small because of large area of cross-section of the sleeper. Hence, ground will not yield under the weight of the train.
The rails themselves are metal. The 'sleepers' the rails rest on are often made from wood - as they flexes while the trains pass over them.
The gaps in the railway tracks are meant to allow the tracks to expand during Hot summers. the rising temperature causes the iron tracks to expand (Linear expansion due to Heat). If there be no space the Iron tracks may bent, as the expansion due to heat causes enormous force. this may even cause the tracks to break.It is only to avoid all of these effects, due to the linear expansion, that a small gap is maintained between joining tracks.Depends on the climate, the strength of the sleepers and the attachment between sleepers and rails.In (northern) Europe, it's quite common to use concrete sleepers and continuous rails. Concrete sleepers are stronger than wooden sleepers, and can withstand the forces of thermal expansion and still keep the rails in place.Weaker sleepers and continuous rails, thermal expansion can force the rails out of alignment with disastrous results.
To keep the rails at a certain spacing, and to spread the weight of the train over a wider area.
To keep the rails at a certain spacing, and to spread the weight of the train over a wider area.
They were used extensively, it is more common nowadays to use reinforced concrete or composite sleepers.
To keep the rails at a certain spacing, and to spread the weight of the train over a wider area.
this is because sleepers increase the area on which pressure of train is to be exerted.Thus pressure is not concentrated on a single point densely.therefore if there more area there would be less pressure and train will run smoothly
That large nail is called a railroad spike.