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Design of Seismic Scaffolding
Design and construction of scaffolding in safety related areas (near rotating equipment, instrument tubing, trip sensitive equipment, control panels, etc.) does require some extra precautions. These guidelines are not intended to be all inclusive. Plant engineering should be consulted for special circumstances. The primary concern associated with scaffold installation in Safety Related areas involves the damage that could be caused to delicate equipment if the scaffold should slide, change shape, collapse or overturn. In order to prevent any scaffold material from coming into contact with safety related system equipment the following guidelines should be observed: Where existing plant guidelines exist for tube and clamp or other system scaffold that are more stringent, the most stringent guidelines should always be used.
1) The scaffold should be designed to meet all federal, state, local and plant safety regulations. 2) The height of the scaffold should not exceed three (3) time the smallest base dimension. 3) The scaffold should be fastened, at the verticals or horizontals, with tube and clamp or equivalent to plant approved structural steel components (i.e.: I-Beams, Handrails, Grating, etc.) at the top, the middle and the base of the scaffold. Whenever possible Excel Click Lock connections should be used. Securing the scaffold jacks to the floor will be effective for securing the base of the scaffold. Diagonal braces and side brackets must not be used to secure the scaffold. 4) To prevent movement, the scaffold should be secured at two (2) separate locations, on opposite corners, (see bracing diagrams). Scaffolds with more than one bay should be secured at as many outside verticals as possible, (see multi-bay scaffold). 5) The scaffold should be installed a minimum of twelve (12) inches form all safety related equipment. When closer installation is required it should receive prior engineering approval. 6) The scaffold must have and installed board deck or should be braced or tied to prevent the scaffold from changing shape, (see bracing diagrams). 7) All pins connecting verticals and all horizontals must be securely fastened. 8) No unnecessary items or scaffold material should be left unsecured on the scaffold at any time. 9) The scaffold should not be left unattended, at any time, until construction is completed, final inspection done and the scaffold is properly tagged stating that it is ready for use. 10) The scaffold should be provided with screens, mesh or other suitable means to prevent materials from being dropped on safety related equipment. Tying off equipment and tools is acceptable. 11) Diagonal braces must be installed on all possible sides and diagonal braces must be wire tied at the ends and when possible in the center. 12) Horizontal wraps should be placed at 3.5 feet intervals. 13) A scaffold with wooden parts, including decking, should be free from holes, saw cuts, splits and gaps. 14) Decking should be completely placed, no holes or missing boards, to help maintain a square and ridged scaffold. 15) All platform decking must be secured (i.e.: wire tied) to the horizontal ledgers that are used for support. 16) The scaffold must be designed to allow access to safety related equipment at all times. 17) The scaffold should be removed immediately upon job completion.
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Note: For more detailed seismic information please refer to our Wyle Labs seismic test data. Wyle Labs Seismic test scaffold design. |
