Typical Substation Gantries 35–500 kV

General information

Switchyard portals are made to typical designs: 3.407.2-162 “Unified steel portals for open switchyards 35–150 kV for ordinary and northern regions”, 3.407.9-149 “Unified reinforced-concrete and steel portals for open switchyards 220–330 kV” and 3.407.9-161 “Unified structures of 500 kV switchyard portals”.

Note. Typical unified portals were designed to standards that have been updated since, so under current requirements they cannot be used without recalculation. POLYGONAL checks typical switchyard portals against current regulatory documents and refines their range of use.

The most rational approach when designing a particular substation is to modify the unified structures: strengthen individual members, change the design, and so on. In projects, modified portals need calculations confirming they meet regulatory requirements. Floodlight masts and lighting poles are used to light substations. Hot-dip galvanising to DSTU EN ISO 1461:2024 is the most effective method of corrosion protection for portal steelwork.

35 kV steel switchyard portals

For ordinary regions

For northern regions

110 kV steel switchyard portals

For ordinary regions

For northern regions

150 kV steel switchyard portals

For ordinary regions

For northern regions

220 kV steel switchyard portals

Sizes

330 kV steel switchyard portals

Sizes

500 kV steel switchyard portals

Sizes

Note

Height, configuration and loads of the portals are as in the relevant typical design (its number is given in the last column).

Manufacture of steel portals

Assembly. Steel switchyard structures are assembled in assembly jigs, which ensures high quality and prevents distortion of the assembled parts that the process does not allow for. Portals are assembled only from carefully straightened parts, enlarged elements and branches, cleaned of burrs, dirt, oil, rust, moisture and ice. Tack welds are made where the welds will be, of the minimum necessary size so that they melt into the welds of the design section, and with the same consumables as the main welding.

Control assembly. The steel structures of portals are fairly complex to assemble and erect, so every first and thereafter every tenth item of structures of one type made in jigs goes through control assembly. In it the dimensions of the structures, the erection joints of individual shipping elements, the match and position of the erection holes and the position of erection devices are checked and accepted. The control assembly includes all elements and parts made with the full set of jigs.

Tilting and transport. When parts and assembled elements are tilted and transported, measures must be taken to keep the specified geometry and prevent local residual deformation of the elements.

Welding is carried out to a process developed in advance: it sets the order of assembly and welding work, the welding methods, the order of the welds, the modes, the diameters and grades of electrodes and wire, and requirements for other welding consumables. Compliance with the process is checked systematically. The process ensures high weld quality, the required geometry and mechanical properties of the joints, and minimal shrinkage stress and distortion. Welding is done by welders who have passed tests and hold certificates of qualification and of admission to the relevant work.

Marking and documents. The finished structures are marked according to the working drawings and erection schemes. A certificate is issued for the portal structures stating that the materials and the finished structures conform to the design, the standards and the requirements of regulatory documents.

Erection is carried out only with an approved work execution plan that contains specific safety solutions; a process for assembly and welding during erection is developed.