Here's a current link:
Field Manual 5-125 - Chapter 4, Anchors and Guy Lines, Figure 4-5. Picket holdfasts (loamy soils)
The parent link {with links to other FM's}:
Field Manual 5-125 - Rigging Techniques, Procedures, and Application
The gin poles you refer to are in FM 5-125, Chapter 5
Lots...