English to Portuguese Tech/Engineering Construction / Civil Engineering construção

Requirements for scaffold toprails and midrails;moving mobile scaffolds; outrigger frames.
Question (1): Under §1926.451(g)(4)(ii), the minimum height for scaffold guardrails manufactured and first placed in service before January 1, 2000, is 36 inches. The minimum guardrail height for scaffolds manufactured or first placed in service after January 1, 2000 is 38 inches. For all scaffolds, the maximum height is 45 inches. You state that your scaffold extensions have rungs spaced 16 inches apart and that when using them, the only way of attaching guardrails is to the rungs. Therefore, when the scaffold board is on the bottom rung of the extension, the toprail has to be 16, 32, or 48 inches high (depending on which rung is used for attaching the guardrail). Is it permissible for to have a toprail height of 32 inches where the platform is small, the exposure time is limited, the same person who erects and dismantles the scaffold will be the one working on it, and a guardrail at 48 inches would interfere with the work surface in some instances?

Answer: Section 1926.451(g)(4)(ii) provides that, "when conditions warrant, the height of the top edge may exceed the 45-inch height, provided the guardrail system meets all other criteria of paragraph (g)(4)." However, the standard does not allow for a height of less than 36 inches. The reason for this is that a guardrail lower than 36 inches would be below the center of gravity of the average worker. A guardrail that is too low would not prevent the worker from falling off the scaffold. Therefore, if you cannot comply with the 45-inch maximum height, you may raise the toprail to 48 inches. Where that would interfere with the work surface, you would have to use a different kind of guardrail system then the one you are using so that you would not be limited by the rung spacing. Alternatively, you could use personal fall protection equipment instead of guardrails (as long as there is an adequate anchorage point).