A high voltage three phase transmission line has a span of 60 km between between point A and B, through an uneven terrain. The terrain of the chosen line route is flat for 18 km from station A, the terrain then slopes up by 0.75 deg for 8 km and then slopes down for 12 km and then from there onwards the terrain is flat to station B. At a distance 4.5 km measured from substation B the route deflects by an angle of 24 degrees.

The conductor characteristic is given below. Calculate the deflected sag and vertical component of the sag for all types of loading, assuming one cubic meter of ice weighs 914.6 kg.

  

 

Physical characteristics Product code APPLE 1120 Strand/wire Alum Steel No/mm No/mm 6/3.00 1/3.00 Cross sectional area Alum Steel Total mm mm mm 42.4 7.1 49.5 Nominal Approximate O.D. mm 9.0 mass kg/km 171 Calculated Calculated minimum final modulus breaking load of elasticity kN GPa 18.3 83 Coefficient of linear expansion /C x 10-6 19.3