Steel lattice towers for 10, 20 and 35 kV transmission lines

In order to comprise all requirements of distributors, and at the same time use the simplest possible storage solutions and to reduce maintenance costs i.e. to unify the construction, a suitable group of steel lattice towers was designed for assembling 20 (10 and 35) kV distribution lines. Towers were designed between 1980 and 1983 for the requirements of the Elektroprivreda company, as part of the medium voltage tower standardisation program for ZEOH at that time, and are now part of the DALEKOVOD d.d. Zagreb manufacturing assortment.

By using extensive experience in design, production and construction of transmission line towers and data on their use, 3 suspension (N – NAH, NAL and NAP) and 5 tension (Z – ZAE, ZAH, ZAJ, ZAL and ZAM) towers were designed, in line with the “Regulation on Technical Standards for Construction of Overhead Power Lines of Nominal Voltage Between 1 and 400 kV” Official Gazette 65/88 (O.G.RH 55/96), where each of them can be used in different conditions present on the transmission line route.

For each tower type a structure prototype was made and it was tested under test load. Based on the examination of the project documentation (calculations and manufacturing blueprints), examination of the prototype structure, testing results and by participation in tests, IGH as the authorised organisation issued attests on testing.

Over 25 years of experience in using towers indicated all structural advantages, precisely because of the possibility of their differentiated use, their suitability to most common situations and deployment requirements. Accordingly, new types of accessorises and new manufacturing technology improvements were made to: the structure itself, presentation of acceptable loads and methods for control and selection of the structure model for the relevant load of each single tower design type group. To the names of towers the additional mark 2 was added, (N – NAH2, NAL2 and NAP2) and (Z – ZAE2, ZAH2, ZAJ2, ZAL2 and ZAM2).

For each single tower type a project documentation was prepared according to the currently valid technical regulations and professional HEP standards (Steel Lattice Tower Standardisation for 20(10) kV Network, mark N.022.03, class no. 4.08/92).