Ratapölkkyjä

Ratapölkkyjä is a Finnish term that translates to "railway sleepers" or "railroad ties" in English. These are the transverse supports used in railway tracks to hold the rails in place and transfer loads from the rails to the ballast. Historically, ratapölkkyjä were primarily made from wood, with materials like pine, spruce, and oak being common choices due to their availability and durability. Wooden sleepers were often treated with preservatives to enhance their lifespan and resistance to decay and insect infestation.

Over time, advancements in materials science led to the introduction of concrete and steel ratapölkkyjä. Concrete sleepers are now widely used, especially on high-speed or heavy-load lines, as they offer greater durability, stability, and resistance to fire and abrasion compared to wood. Steel sleepers are also employed in certain applications, though they are less common than wood or concrete.

The primary function of ratapölkkyjä is to maintain the gauge of the track, ensuring the correct distance between the two rails. They also provide a stable base for the rails and help to distribute the weight of passing trains over a larger area of ballast, preventing excessive settlement of the track. The design and material of ratapölkkyjä are critical factors in the safety, performance, and maintenance of railway infrastructure.