30 C.F.R. § 56.14206 Securing movable parts.
Title 30 - Mineral Resources
(a) When moving mobile equipment between workplaces, booms, forks, buckets, beds, and similar movable parts of the equipment shall be positioned in the travel mode and, if required for safe travel, mechanically secured. (b) When mobile equipment is unattended or not in use, dippers, buckets and scraper blades shall be lowered to the ground. Other movable parts, such as booms, shall be mechanically secured or positioned to prevent movement which would create a hazard to persons. [53 FR 32521, Aug. 25, 1988; 53 FR 44588, Nov. 4, 1988]
Title 30: Mineral Resources
PART 56—SAFETY AND HEALTH STANDARDS—SURFACE METAL AND NONMETAL MINES
Subpart M—Machinery and Equipment
Safety Practices and Operational Procedures
§ 56.14206 Securing movable parts.

