The second category of protective system proscribed by OSHA to protect employees from cave-ins involves the use of support systems, shield systems, and other protective systems. The use of this category also requires the use of one of four design options.
The first option is to use Appendices A and C or D. For timber shoring and trenches Appendix A- Soil Classification and Appendix C- Timber Shoring are to be used. Hydraulic shoring of trenches calls for use of either option two, manufacturer’s tabulated data, or Appendix D- Aluminum Hydraulic Shoring. Appendix D is to be used when manufacturers' tabulated data are not available.
The second option is to use manufacturers' tabulated data. Design of support shields or other protective systems using these data must agree with all specifications, recommendations, and limitations issued or made by the manufacturer. Deviations are allowed only with the manufacturers' written specific approval. These data are to be in written form and kept at the job site during construction of the protective system.
The third option, when choosing the use of support, shield, or other protective systems is design using other tabulated data. The contractor may select from designs in agreement with tabulated data such as tables and charts approved by a registered professional engineer. The written data are to be kept at the job site during construction of the protective system and shall include the parameters that affect system selection, the limits of data usage, and explanatory information necessary to make the correct systems selection.
The fourth option is to use a design approved by a registered professional engineer. Such designs are to be written, kept at the job site during construction of the protective system, and include a plan indication the size, types, and configuration of the materials to be used and the identity of the approving registered PE.
Materials and equipment used for protective systems must be free from damage or defects that might impair their proper function. A competent person shall examine damaged material or equipment to evaluate its suitability for continued use. Material or equipment found unsafe for continued use shall be removed from service. Members of support systems are to be securely connected to prevent sliding, falling, kick outs, or other predictable failures.