Before authorizing steel erection to begin, the controlling contractor must make sure the steel erector receives written notification that the footing, pier and wall concrete, and the mortar of masonry piers and walls, has reached, as shown by a suitable ASTM test method on samples cured in the field, either 75 percent of the minimum compressive strength intended in the design or enough strength for erection loads, and that any anchor bolt repairs, replacements or modifications were done under 1926.755(b). The steel erection contractor in turn may not erect steel until it has received the written notification on concrete and mortar strength. The controlling contractor must provide and maintain adequate roads into and across the site so that cranes, derricks, trucks, other equipment and the steel can be delivered and moved safely, together with means and methods for controlling pedestrians and vehicles (roads outside the site are excluded), and a firm, properly graded and drained area near the work with enough space for safe material storage and for the erector's equipment to operate safely. All hoisting operations in steel erection must be pre-planned so that the working-under-loads rules of 1926.753(d) are met. Where an employer chooses, because of site conditions, to use alternate means and methods allowed by 1926.757(e)(4), 1926.757(a)(4) or 1926.753(c)(5), a qualified person must develop a site-specific erection plan and it must be available at the work site; non-mandatory Appendix A gives guidelines for its content.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.