Bearers, or sleepers, are components made of concrete, steel, or wood. Sleepers are part of the railway track structure placed between the rails and the ballast; they transfer forces from the rails to the ballast and maintain the gauge of the track.
Concrete Sleepers
Concrete sleepers are available in several forms, with the most important being Monoblock, double block, and sectional. The difference among their models lies in their production methods, which can be either prestressed or non-prestressed. Prestressed concrete sleepers incorporate numerous steel reinforcement bars in the midpoint to prevent cracking and reduce weight while increasing strength.
Wooden Sleepers
These wooden sleepers must have a high density of fibers and a low moisture percentage. Typically, these woods come from species such as coniferous pine, beech, oak, poplar, or alder. The lifespan of these sleepers depends on their resistance to corrosion, decay, cracking, and insect infestation. To protect and extend the lifespan of these sleepers further, oils or coal tar are used for saturation.
Steel Sleepers
These steel sleepers are made from a rolled profile measuring between 2.5 to 2.6 meters in length and weighing between 75 to 90 kilograms. The operations related to creating holes in sleepers must be carried out with great accuracy, with dimensions not exceeding 0.5 millimeters and a spacing of 0.75 millimeters between them. Disadvantages of these sleepers include rusting, being a good conductor of electricity, and generating a lot of noise.
