Although our original ground anchor was very popular, we found that we could further increase the resistance by adding a second plate to the anchor to lock all three spikes in position, thus preventing any of the spikes from working loose independently. The result is a substantial increase in pull-out resistance.
Tested in a mature lawn with loamy soil and partial sunlight, the Model II anchor showed resistance values of 700 lb in a vertical pull, 1500 lb in a 45° pull, and 2,000 lb for a pull parallel to the ground. The anchor has greatest pull-out resistance in hard packed soil but is most commonly used in mature lawns like the one we used for testing.
The anchor can be used in loosely-tilled soil or in sandy soil that has minimal grass root structure but both will have reduced pull-out resistance for obvious reasons. The level of ground moisture can also alter pull-out forces. For example, if the soil is oversaturated due to spring run-off or heavy rainfall, it will lower the pull-out resistance but if the soil is dry and hard-baked by a hot summer sun, it will raise the resistance.
Comes with three 12" long spiral spikes, two anchor plates (one in which to drive the spikes and the other to lock them in position) and one eye bolt. All components of the anchor are made of galvanized steel.