In the process of building a railway, two main components are needed: rails and sleepers, which serve as a support for them. In most cases, wood elements (pine, birch, fir) are used, differing in size, weight, length and other technical characteristics.
Wooden sleepers have both their advantages and disadvantages. Wooden poles are subject to decay, especially in places of contact with rails. However, the advantages of such sleepers are much greater:
- simplicity in processing material;
- elasticity with light weight;
- good interaction with the base;
- resistance to temperature differences.
Due to these advantages, impregnated sleepers are used without any restrictions. As a result of a good combination with the base, they are used not only in the process of laying railway tracks, but also in construction. Their weight and strength allow them to withstand heavy loads.
Technical specifications
GOST standard 78-2004 entered into force on 01.01.2006. It applies to wooden poles designed for wide gauge railways. The scope of their application can be the construction and repair of railways, where the gauges are up to 1.52 m long, the construction of buildings and structures. The average weight is 80–90 kg.
According to GOST 78-2004, sleepers made of wood are of three types:
- targets main roads;
- for stationary and bypass routes;
- for underutilized access roads located on an industrial site.
Repairs
If the sleepers are used improperly, they are quickly destroyed, so they are soaked with special antiseptics. Thus, protection against harmful effects mold fungus, various insects.
Impregnated sleepers are used for a longer period.
After repair of the railway tracks, the products are sorted:
- The main and other ways related to grades 1-3. The size at the notch is 14 cm. There are no splits and rot.
- All paths are 3-4 classes. The size at the notch is 13 cm, the bushings do not extend to the lower part of the pastel, there is no rot of the end part.
- Any ways related to grade 5. These are wooden sleepers, which were not included in the first two groups with a notch size of 12 cm or more.
According to GOST 78-2004, sleepers after repair work must meet the following requirements:
- No pronounced rot.
- Old holes from the mounts are sealed with special plugs, and new ones are already prepared.
- The ends are protected from cracking by brackets, screws and other elements.
- The dimensions of the cracks are acceptable and treated with antiseptics and waterproofing material.
Improper use or mechanical damage can shorten the life of the bearings.
You can understand that the elements have become unusable by a number of signs:
- The size of the crutch holes exceeds 3 cm.
- There is rot or puncture under the lining.
- Rotting ends.
- Fractures appeared across the cross ties.
Processing types
In the production process of sleepers, in order to increase their service life, various types of wood impregnations can be used. They are oily and water soluble.
The first type is made from coal and wood products. It is used both in solid form and by mixing with solutions and oils. The second type can be produced in the form of a solution and by weight (in solid state).
To increase the service life of the tracks using oil antiseptics, the best choice is coal tar oil for impregnation. It is actively used in the production of sleepers in the United States, Europe and the Russian Federation.
Wooden sleepers are used not only in the railway sector. Due to their weight and strength, they are used in the construction of new buildings. And impregnations improve their properties and technical characteristics.