This SAE Recommended Practice establishes the test procedures and minimum performance criteria necessary to fulfill the intended purpose and is applicable to Skidders, Grapple Skidders, and Crawlers when used in the harvesting of trees.

Structures meeting these performance criteria may not provide complete operator protection under all conceivable circumstances, but they are expected to minimize the possibility of operator injury under reasonable operating situations.

The performance requirements and test criteria included in this document are derived from investigations on operator protection that has performed the intended function in a variety of actual operating conditions.

This document is intended to establish a consistent, repeatable means of evaluating Operator Protective Structures (OPS) on skidders, Grapple Skidders, and Crawlers when used in the harvesting of trees. Operator Protective Structures are structures/enclosures whose primary purpose is to minimize the possibility of operator injury from hazards such as whipping saplings, branches, jill-poking (spear-like objects), and snapping winch lines with the least adverse effect on operator visibility, comfort, and protection from other hazards.