Proper orientation and correct installation of Poles and Masts is vital for maximum performance and durability.
Poles and masts must be installed correctly i.e. facing the right way to ensure that they can withstand wind forces which play on the conductor lines between the poles or masts. These are the greatest forces the poles or masts will have to bear and it is therefore crucial that the I-sections of the poles or masts face the same way as the conductors (Figure 1 and 2 - please see attachment).
Planting of poles and masts
Poles and masts must be planted to the minimum depth as specified in this brochure. The holes can be hand dug, machine excavated or augured. Depending on soil conditions, the least amount of disturbance to the surrounding ground, the better.
- Auger the hole – minimum auger size should be 200mm – 250mm greater in diameter than the pole butt.
- To install a pole or mast, choke it with a nylon sling 30% in from the tip, and lift it into a vertical position with the butt resting on the ground. Now lift pole or mast off the ground, position it over the augured hole and lower it until the butt rests on the bottom and in the centre of the hole.
- While holding the pole or mast in position, shovel in the backfill. Tamp backfill and check plumb levels every 100mm.
- Remove the sling and move on to the next pole or mast while filling and tamping continues to a point 50mm above ground level.
In all situations where poles or masts have large loadings, heavy unbalanced loads, or where soil strengths are suspect, an engineer should check that the soil has adequate bearing strength to prevent poles from leaning or toppling.
In all but extreme cases, all that may be required is a slight increase in the bearing surface below ground level. This can be achieved in a number of ways. The easiest is by simply setting the pole deeper, or by auguring a larger hole and backfilling with concrete or a crusher run-type material.