Overhead Power Easements - Baseline Group Ltd

ClientMainpower NZ LimitedLocationNew Zealand
ConsultantCraig TinklerContractorCraig Tinkler

Project Summary

The creation of easements for overhead power lines at multiple sites in Canterbury, New Zealand.


The Challenge

The jobs involved the surveying of power poles and their stays, with the creation of easements a certain width from the centre of the power poles and including areas covering the anchoring stays and blocks. Generally, these were reasonably long runs (up to 50 power poles with stays at every significant bend . This meant that calculating the easement lines and entering the data into a traverse spreadsheet for importing into Landonline was quite time-consuming.

The approach in the field for surveying the poles differed for each staff member – some would do a single offset shot, some would take two shots equal distance either side of a pole, and some would observe four points around the pole. The stays were always measured as a single point where they enter the ground, and always connected to the pole at the top.

As a result, calculations involved the creation of a string for the main centreline of the power line, creation of the string representing the stay. The required lines would then be calculated by offsetting or extending these strings as necessary, splitting them wherever they crossed existing boundaries in a traverse spreadsheet. The strings were then traced into the traverse spreadsheet and unique identifiers typed into the traverse spreadsheet for each point created.


The Solution

A macro was written which carried out all of the abovementioned calculations, except for the tracing of the strings into the traverse spreadsheet - i.e. the macro calculates the power pole centreline and stay strings, creates the strings for the easements and assigns a unique identifier to each of the vertices, calculates the intersections with the boundaries in the traverse spreadsheet, and splits the strings as necessary.


The Result

The macro resulted in a considerable time saving for the firm, as the calculations could all be completed in the time it took to fill in the macro fields. The client was very pleased with this expedited process.


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