The use of wood material in the arrangement of communication infrastructure justifies itself in many ways. One of the key factors for this choice for many users is the low price. Cheap poles alone are inexpensive and practically do not require maintenance investments during operation. This solution also facilitates the operation of power lines (power lines) in severe weather conditions. Natural material resists both frosts and heavy wind, and also does not undergo destruction under the influence of moisture. On the other hand, the wooden poles of power lines have many disadvantages, which are mostly in modest strength indicators. One way or another, there are many organizations involved in the maintenance of electric networks that rely on this particular type of support.
Preparation of wood raw materials for poles
As a basis for poles supporting power lines, solid arrays of predominantly coniferous species are selected. As a rule, due to the high strength and resistance to external influences, pine or fir is selected for such needs. Sometimes larch logs are also used. Regardless of the breeds selected, each blank is subjected to a thorough examination for damage by fungi and insects. This is important for the subsequent maintenance of optimal technical and operational performance. Depending on the technology by which the production of wooden poles of power lines will be carried out, the primary processing of the base may include peeling and debarking operations. Using special machines, the logs are processed, during which the top layer is removed, so that in the future it does not interfere with the penetration of protective impregnation.
Manufacturing Technology
The main stage in the production of support logs nevertheless involves the implementation of machining in order to form technological openings with holes. Horizontal ends are protected with special pastes already at the stage of basic refinement. If necessary, existing cuts, spalls and edges are corrected - they can be eliminated provided that the depth is not more than 10% of the diameter of the workpiece. To maintain accuracy in the machining process, the production of wooden transmission line poles at some enterprises involves the use of special templates. On them, for example, the parameters of the hedges and nicks are checked.
Next, the drying step begins, which prepares the wood for impregnation. According to the standards, protective equipment can be applied only provided that the moisture content of the array is not more than 28%. The barked logs are dried in special thermal chambers, which are distinguished by an unusual design. The fact is that in such units hot air currents are not directed to the workpiece, but circulate around it. Thus, cracking and overheating of the material is not allowed.
Support impregnation
The use of special impregnations is aimed at protecting wood from rotting, destruction of the structure and, in general, loss of operational properties before external influences. In particular, protective compounds protect the wooden poles of power lines from fungal damage, corrosion by insects and the development of mold. Such protection, for example, provides an antiseptic water-soluble drug from the CCA family. This tool is characterized by increased efficiency and environmental safety, which made it one of the most common types of impregnations.
At the first stage, after application, a vacuum is formed in some way, which helps to remove excess moisture from the wood pores. Subsequently, the active components of the composition dissolve throughout the structure of the tree, strengthening it and forming a protective barrier.
Dimensions and Weight
There are several categories of support pillars that cause differences in size. So, the initial level is 9.5 m long logs that are 160 mm in diameter. The mass of such a workpiece is 200 kg. This is followed by supports of medium strength, which can reach a length of 11 m, their diameter is already 210 mm, and the mass is 300 kg. From the point of view of ability to endure physical loads, the most powerful structures can be built with a wooden support for power lines, the weight of which reaches 400 kg At the same time, the length remains the same as in the case of medium-strength pillars - 11 m. But the diameter of such a support increases to 240 mm.
Service life
Depending on the production technology, the average life can vary from 10 to 20 years. This is precisely the middle corridor, since there are logs whose working life does not exceed 5 years, as well as high-strength structures that retain their original properties after 50 years. As a rule, the warranty service life of wooden poles of power lines does not exceed 10 years. In practice, most often ordinary pillars of this type are used for 5-7 years. Such a short period is due to the lack of proper maintenance of the object or the fact that at the manufacturing stage no special impregnation was used at all. By the way, depending on the characteristics of the protective equipment, the working life of the support can last 4-6 years. Modern drugs are valid up to 15 years. However, much depends on how correctly the composition processing technique was performed.
Quality control
In the manufacturing process of the support, several stages of quality control take place. The first involves examining an element of a future power line for geometric accuracy. After that, the workpiece is sent for drying. Before impregnation, the material is checked for moisture, which should not exceed 28%. Further, control verification measures are provided, during which the characteristics of the protective agent with which the wooden supports of the power transmission line were processed are determined. Installation rules require that the material be delivered to the installation site with an optimally impregnated structure. To comply with this condition, technologists evaluate the depth of impregnation, and based on the results of the analysis, an appropriate quality certificate is formed.
Rebar assembly
In the process of assembly activities, the support is equipped with functional equipment, which will be required when connecting to a power line. The installation plan usually involves marking the location of the hooks, creating holes for the hooks and the direct installation of fittings with insulators. Hook points are marked using a template that can be made from a piece of aluminum rectangular bus. As a rule, the installation of wooden poles of power lines with the use of drilling is performed on special machines in the factory. This ensures high precision and consistent quality. However, during transportation, the assembled structure can be damaged, so processing the workpiece with mounting actions is sometimes carried out directly at the installation site. In this case, a cordless power tool in the form of screwdrivers with a drill function is used.
Installation technique
Most often, installation is performed using crane-boring machines. Only in some cases, when working with heavy or overall structures, tractor cranes are required. At the installation site, the pit is first formed in which the pole will be installed. It must be carefully compacted, if necessary, drain and cover with special insulators. Next, a direct installation of the wooden poles of the power transmission line is carried out using the technique. The working bodies of the crane or crane- drilling machine fix the prepared column, and then move it into the pit. But this applies to lightweight supports whose height does not exceed 10 m. Heavy logs are installed in pits with concrete prefixes - this is a kind of foundation in which the column is mechanically fixed.
Bearing Manufacturers
In Russia, products in the form of components and consumables for equipping power lines are quite widely represented. One of the largest representatives of this niche is the Kotelnich mast-impregnation plant. This company has been manufacturing high-quality wooden poles for more than 30 years, and in recent years it has successfully switched to high-tech automated production. However, many manufacturers of wooden power transmission line poles in Russia are engaged in capacity upgrades, among which OSMK and ProfTrade enterprises also stand out. If the first manufacturer mentioned focuses specifically on the production of supports, then in the assortment of these companies you can also find reinforcement components, insulation materials and auxiliary elements specifically for the characteristics of specific supports.
Reinforced concrete structures as an alternative
It should immediately be noted that from the point of view of operation, it is more profitable to use reinforced concrete structures. They are more reliable in all technical parameters, but, of course, are much more expensive. In turn, the wooden poles of the power lines, even in the best versions, can only come close to the characteristics of reinforced concrete structures with one way or another success. This material, and subject to high-quality impregnation, will not be able to last as long as the concrete structure. However, low life is offset by cost. Regular replacement of pillars at intervals of at least 5 years fits the budget for the use of reinforced concrete analogues.
Conclusion
Wooden poles designed to organize power lines confirm the value of natural building materials. Even modern fiberglass-based plastics are not able to replace such pillars. Of course, this does not mean that the wooden poles of power lines outperform composites in terms of strength and protection from external destructive influences. Moreover, the same fiberglass in a number of characteristics ahead of concrete structures. But if you evaluate materials in terms of qualities, then wood is more practical. It is easier to process, produce, deliver and carry out installation operations with it.