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wind speeds up to the 50-year maximum gust value. Spirafix recommend that a pull test be done
prior to installing the anchor to ensure the ground is suitable. The graph is to be used as a guide
only.
Because the ground anchors (and turbine) have survival limits and the destructive force of the wind
increases exponentially with wind speed, it is important to consider lowering the tower when very
strong winds are forecast. This will reduce the chance of damage to the equipment.
Strong winds will cause the ground anchors to be loaded in varying directions over time so it is
important to check the anchors on a regular basis (the frequency dependant on weather and ground
conditions).
Installation Procedure
Step 1 – Setting out
Once you are happy with your chosen location, start marking out the position of the Spirafix ground
anchors. Cut a piece of string, make a loop in one end and trim it so it was the radius of the circle for
the four, peripheral anchors (3m long). If space is a little limited and the ground uneven the piece of
string is also ideal for finding the best location for the central anchor. Do this by attaching one end to
a stake that represents the central anchor (A1) and walk the circle whilst holding the end.
