Code of Practice for Safe Use and Operation of Suspended Working ...

5. DESIGN AND CONSTRUCTION5.1 General5.1.1 A suspended working platform should be capable of sustaining all loadsapplied to the complete unit. These loads should comprise the self weightof the suspended working platform, the safe working load, moving loads,impact loads and wind loads.5.1.2 Particular attention should be given to the rigidity and retention of theworking platform. Each unit of the suspended working platform shouldbe so designed that an omission or failure of any individual joints or fixingcomponent will not result in the structural collapse of the working platformcausing danger to the safety of the occupants. All fittings and connectionsshould be so designed that when assembled no part can becomeaccidentally detached.5.1.3 The structural design of the working platform, the suspension points andthe members of the suspension systems should be based on the ropetensions and load outputs of the suspension systems, taking into accountthe load output of any pulley system used in the suspension system.5.1.4 The roof rig should be designed so that the permissible stressesappropriate to the materials of the construction are not exceeded whenthe maximum total suspended load is applied to the suspension point. Inaddition, the design should ensure that 90% of the minimum yield stressof the materials used is not exceeded when the maximum rope tension isdeveloped as a result of the operation of slipping clutches, load limitingdevices, stalling torque, etc.5.1.5 All materials and components used in the construction and assembly ofthe suspended working platform should be of sound construction andadequate for the purpose for which they are intended. Welded steel jointsshould be made in accordance with the requirements of BS 5135 : 1984-Specification for arc welding of carbon and carbon manganese steels,and should be suitably protected against corrosion.17