Weight span calculations for various anchor towers and river crossing towers are done as follows :

a = L / 2 + Th / WL

where,
L = Considered anchor crossing span in meters.
T = Tension at 00 C No=wind for equivalent span under normal condition or 320 F/W for worst condition in kg.
h = Height difference with respect to adjacent tower in meters.

The negative value of 'a' for anchor spans determines the uplift on the anchor tower. The uplift in kg is determined by multiplying the above uplift (in meters) by the weight of conductor/meter. Uplift on a tower up to the limit which can be encountered by the weight of insulator string can be allowed without providing any reinforcement on cross arms of towers.