What 29 CFR 1926.600 requires (plain English)
29 CFR 1926.600 sets general safety requirements for equipment in Subpart O (Motor Vehicles, Mechanized Equipment, and Marine Operations). It covers a range of practical safeguards for the heavy equipment used across construction sites.
Two of its best-known rules address recurring fatal hazards. First, visibility of unattended equipment: all equipment left unattended at night, adjacent to a highway in normal use or adjacent to construction areas where work is in progress, must have appropriate lights or reflectors, or barricades equipped with appropriate lights or reflectors, to identify the location of the equipment, so vehicles do not strike unseen equipment in the dark. Second, blocking suspended parts: heavy machinery, equipment, or parts thereof which are suspended or held aloft by slings, hoists, or jacks must be substantially blocked or cribbed to prevent falling or shifting before employees are permitted to work under or between them.
The section also addresses safe parking and securing of equipment (setting brakes, lowering blades or buckets, chocking wheels on inclines), the requirements that apply when equipment works or is moved in the vicinity of power lines or energized transmitters (1926.600(a)(6)), and the master switch or similar means where required. Throughout, 1926.600 targets the struck-by and crushing hazards that heavy construction equipment presents: being hit by unlit equipment, or crushed by a part that drops when its hydraulic or mechanical support fails.