Requirements for wood products used in railway transport

Precast concrete sleepers are commonly used in the construction of railways. They have many advantages and features that have made them a permanent element of the railway infrastructure. However, wooden sleepers are still used; they have many advantages, such as good vibration damping and temperature resistance. Due to their weight, they are used on routes where there is a problem with the trackbed. Economics is also one of the reasons for their use. Wood is a natural material that decomposes under the influence of biological and environmental factors without adequate protection. It is, therefore, necessary to adequately protect wood material against the effects of the environment in which it is used. The paper discusses the requirements that must be met by wooden products used to build the railway pavement. The types of wood from which the wooden materials of the railway superstructure are made are presented. The structure of wood and the properties of hard and soft wood were also discussed. The current regulations and standards classifying the kinds and types and dimensions of wood materials and regulating the requirements for wood materials of the railway superstructure are also presented. Issues arising from the ambiguities and shortcomings of these provisions and standards were also raised. The process of impregnating wood materials of the railway pavement with creosote oil using the Rüping vacuum-pressure method was also discussed. These types of oil are not neutral to the environment, especially those of the older generation that contained large amounts of highly toxic and carcinogenic substances, especially benz-a-pyrene. The analyzed material shows that there are some deficiencies as to the brightness, exact and explicit requirements for wood and impregnation. This is a certain problem for the entire range of products used.