We did some training with the pickets on our rig the other day. Picket systems used for anchors are limited by the soil type you are dealing with. Ordinary soils have greater holding power than clay and gravel mixtures. Sand has about half the holding power of ordinary soils. Keep soil types in mind when determining how much holding power you can anticipate.
In ordinary soils a single picket can hold up to 700 lbf. A 1-1-1 combination of pickets in a line and lashed together will hold about 1,800 lbf. A 3-2-1 combination can hold up to 4,000 lbf.
Pickets are typically made of 1″ diameter rolled steel that is 4′ long.
The pickets should be driven 2′-3′ into the soil (2′ in stable soil and up to 3′ in unstable soil) at a 15 degree angle away from the planned load.
When connecting the pickets, use a 20′ piece of webbing or 1/2″ utility rope. Connect the base of the read picket with a clove hitch and wrap the webbing or rope to the top of the forward picket up to 6 times (finish with another clove hitch). Use a piece of wood or rebar or another picket inserted between the wrap to twist the pickets. Tension until the forward picket starts to move, then back off one half turn and drive stake into the ground.
Pass it on!