BASIC INFORMATION ON PURPOSE AND STRUCTURE OF TOWERS

The purpose of the structure

With difference from towers designed for very specific cross sections and structures of conductors, these towers represent typified structure solutions where each type can be used in different geographical conditions for more different types of conductors, with different cross sections and structures.

For the required conductor cross-section and specific locations, by correct selection of the maximum working stress and corresponding arrangement of suspensions, i.e. points of connecting the earth wire to the structure, each tower can be used:

  • in all climate conditions:
    • nominal wind load 500 – 1100 (1300) N/m2
    • additional load coefficient 1 to 4 x 0.18.d daN/m’
  • on all terrains, without regard of the configuration
  • for earth wires with different cross-sections:
    • AL/Č between 35/6 mm2 and 150/25 mm2
    • other types of insulated and non insulated conductors, that put weight on the tower with the corresponding resulting tension force and wind facing surface
  • for connecting post type, long rod, string insulators (directly to the cross-arm, over hinges, shackles, extension links and spacers)
  • for one, and for two systems
  • with, or without earth wire
  • for use of additional equipment without requiring customisation of the structure:
    • overhead and underground cable tap-offs, overhead-underground transition
    • line disconnectors (with or without remote control), malfunction detection, etc.
  • as gantries

Basic structure information

Towers are four sided pyramids of steel - lattice grid. Made of standard hot rolled profiles connected with bolts, with single diagonal filling in the total length of the tower. Two sides of suspension towers that are designed for light and medium loads shall be made of horizontal steel plate welded to tower main legs instead of diagonals fixed with bolts.

Corrosion protection of all tower parts is made by hot dip galvanizing, in quality that satisfies renown world standards.

All towers are designed with parallel sides of the upper section (tower head without incremental adjustments). In this way it is possible to use same cross-arms for different disposition of earth wires – numerous different symmetrical and asymmetrical heads, and makes possible to connect same accessories on different tower heights as also on different types of towers.

Tower sections with incremental adjustment are selected on purpose to use one or at most two different profile dimensions for tower main legs at all heights. Each tower section diagonal has the same length, profile dimension and corresponding bolts.

Type, material, dimensions and manufacturing of tower structures enable:

  • simple storage and transport (for different dimensions and transportation means)
  • quick installation and removal (by elements, sections, as a whole) with or without mechanisation
  • changing the function of a tower on the already constructed transmission lines
  • simple maintenance and interventions during exploitation:
    • open profiles suitable for monitoring and maintenance
    • simple replacement of damaged elements and reparation of corrosion protection
ISO 14001 ISO 9001 OHSAS 18000