To secure a cubic-shaped boulder, how many tiedowns are required, at minimum?

Special Circumstances: Securing a Cubic-Shaped Boulder The securement of a cubic-shaped boulder must meet these requirements in addition to the other large boulder requirements in Section 13. Secure each boulder individually with at least two chain tiedowns placed side-to-side across the vehicle. Place tiedowns as closely as possible to the hardwood blocking used to support the boulder.