A dock leveler is a hinged platform built into the dock edge that bridges the gap and height difference between the dock floor and a trailer bed, so a forklift can drive in and out.
Levelers come as hydraulic, air-powered or mechanical units built into a pit, while portable dock plates and dockboards serve the same purpose where there is no built-in leveler. OSHA 1910.26 requires dockboards to be capable of supporting the maximum intended load and portable dockboards to be secured so they do not move, and 1910.178 requires drivers to drive over dockboards and bridge plates carefully and slowly once secured and never above their rated capacity.
The hazards are a lip that does not fully rest on the trailer bed, a leveler that drops when the trailer moves, a portable plate that slides, and a capacity that a laden truck exceeds. Capacity needs to cover the forklift, the load and the impact of crossing at speed, not just the load. Daily checks, lip and hinge inspection, and interlocks that tie the leveler to the trailer restraint reduce these risks. The loading dock forklift safety guide covers dock plate failures.