Stages of power line construction

The construction of power lines includes: route development, design, approval of the prepared project, surveying work, installation.
Based on the design documents, all power line construction stages are carried out.
Development of the route

• First of all, the location is determined and coordinated, taking into account specific rules:
• The future power line should have minimized contact with railroad tracks and highways;
• Reduce the area of sidewalks and bicycle paths near power lines;
• The length of the transmission line shall be selected using the shortest distance method between the start and endpoints.

For coordination and approval of the route, documents shall be prepared for:

• Allocation of territories for the installation of the power line;
• Obtaining permits for cutting trees;
• Costing and determining the type of work.
• After getting tickets, start engineering.

Designing
When drafting the design and technical documentation, takes into account:

• The climatic characteristics of the region (e.g., wind load);
• Geological and geodesic features of the area: topography, soil conditions;
• Information about communications and engineering networks located along the route;
• Wishes of the customer;
• Test task.

Environmental pollution, wind load, and climate are also taken into account. The project is a mandatory manner display:

• Capital structures that are in the vicinity;
• Communications;
• Objects affecting the remoteness of the transmission line and the choice of materials.

When designing, the place of the transmission line shall be determined so that the traffic and pedestrian movement would be unobstructed. Nodes are located in an accessible location to allow for quick repairs and routine maintenance.

After obtaining the data on engineering and geodesic works, a plan is prepared. It is sent for approval to land users and the organization; on the balance sheet, there is a site for constructing the power line.

After the document is signed, design and technical documentation are prepared, in which sections are developed:

• Determination of the load on the transmission line, which occurs under the action of ice, wind, and other climatic factors;
• Listing the measures used to protect the environment and the safety of workers during the installation of transmission lines;
• With the solution of ensuring reliability with justifications and calculations of the equipment used;
• With the choice of relay protection and line automatics;
• Fire safety measures;
• The length of the transmission line;
• with the direction of the routes;
• With the drawings of the metal structures, supports
• With the plan of the territory;
• Graphic documents.

The prepared documentation is checked by an employee of the design organization, who corrects deficiencies if necessary.
Project approval
The design and technical documentation for the transmission line are approved by:

• The organization that owns the utilities that cross the transmission line or fall within its protection zone;
• Experts in the local power distribution network service;
• An owner of the land plot through which the transmission line is located;
• Specialist of the Federal Service for Nuclear, Environmental and Technological Supervision.
• After the detailed design is approved, construction begins.

Power Line Construction
Power line construction begins with preparing suitable conditions for the work crew. To do this:

• Plan a site for the installation of the pole;
• Create a structure for temporary housing for the team;
• Setting up temporary bases for material storage;
• Construct one or more access roads;
• Marking of the territory.

Power transmission line design and installation cannot be carried out without poles. Most often, a structure made of reinforced concrete or metal is used. First, the places under the supports are drilled. For this purpose, specialized equipment is involved, high-altitude installation work is carried out, and machines that can lift heavy loads are used.

The next step is the construction of insulation, without which it is not possible to put the transmission line into operation. It is necessary to install the cables on the poles. The insulation is attached to the beams. To ensure failure-free operation of the system, the manipulation is carried out by specialists.

After the supports are installed, the cables are attached. To do this, a unique technique is used, which performs pulling. If the line is over 10 kW, then use a CIP cable. Wire of this type increases the reliability and safety of the overhead line and makes its maintenance more economical.

Each wire passes through an insulator, which comes in different types:

• Glass;
• Porcelain;
• Polymer.

Type is chosen based on the local climate and possible environmental contamination. For lines with a voltage of 35 to 220 kW, preference is given to polymer or glass material.
There are two types of insulators according to the way cables are fixed:

• Pinned (mounted on a hook or pin);
• Suspended (fixed with fittings to poles).

The pin type can be used only on light wires. The cable itself is fixed on the head or neck of the insulator, depending on the type of support chosen.