Design Parameters Specification for the Construction of 33kV Overhead Lines across Lagoon Using Transmission Towers

Overhead aluminium conductors used for both medium and high voltage installations are flexible and
uniform in weight along their lengths. They often take the form of catenary changes with conductor
temperature, ice and wind loading and time. Adequate vertical and horizontal clearance under all
weather and electrical loading conditions are guaranteed by ensuring the breaking strength of the
conductor is not exceeded. Thus, the behaviour of the conductor catenary under all conditions need to
be incorporated into the transmission line in the constructional design regardless of the length of the
transmission line. Overhead transmission lines constructed across water such as Lagoon are good
illustration of the characteristics described above. Therefore, this research presents a case study of
33kV overhead line construction crossing 265 m wide ‘Lagoon’ which requires Sag parameter
calculations. Detail description of the case study, specifications for Aluminium conductor steel
reinforced (ACSR) type A1/S1A IEC 61089 standard and sag calculations with and without wind or ice
weather conditions are presented. The design calculation for weight of a required Dead-End Lattice
Tower via determination of weight of the individual 5 components of a Tower are also presented. The
obtained results are presented and discussed. The Sag parameter results and that of Dead-end lattice
tower and its components weights evaluated were applied to the proposed project. The method of this
research work generated reliable results suggesting that it can be applied to any other Transmission
tower successfully.