The accompanying files are scenarios modeled directly from worked examples in HB 331-2012 Overhead line design.

The worked examples are from the following sections:

  • section 26.7.1
  • section 26.7.4
  • section 27.3.2

You can use these files as training exercises to see whether you can achieve the same results.


The calculations in HB 331-2012 are based on a naive calculation method where it assumes the angle of incidence between the wind and conductor is always 90°, regardless of the arrangement of the conductors on the pole. This method works well on the cases of on straight through spans with small deviation angles, but will increase in error as the angle of deviation increase. It will also be error prone on T-off models and corner pole arrangements. 

A common alternative is direction sampling, where the effect of wind is evaluated at even intervals all around the pole. This method will produce a large number results (as specified by the user), and the maximum result is determined as the maximum tip load force. This method will work for cases where the wind direction can be considered as a uniform vector applied to all components on the pole model.

Power Lines Pro can perform both types of calculations. The direction-less results will be the same as the HB 331-2012 results. The direction sampling will provide more realistic results for models other than straight through spans, and is very close to the worked examples for small deviation angles.

To learn how to switch between the calculation methods see Tip Load Calculation Method in Advanced Tip Load Features