Sag of Transmission Line Calculator (Same Height Supports)

Sag of Transmission Line Calculator

Calculate the sag of a transmission line with supports at the same height using:
\[ f \approx \sqrt{\frac{3L(S-L)}{8}} \]

* Enter the horizontal span \( L \) (m) and the total cable length \( S \) (m). Note that \( S \) must be greater than \( L \).

Step 1: Enter Parameters

Example: 300 m

Example: 310 m (must be greater than L)

Derived Formula: \( f \approx \sqrt{\frac{3L(S-L)}{8}} \)


Practical Example:
For a horizontal span \( L = 300\,\text{m} \) and a cable length \( S = 310\,\text{m} \),
the sag is approximately calculated using the above formula.