Safety Flash -Steel Collapse

TIME: February 12, 2015 LOCATION: North Haven, CT


DESCRIPTION OF EVENT: A bundle of decking, weighing approximately 4,000 pounds, was hoisted by a crane and placed across several 80-foot bar joists of a steel structure currently under construction. The bundle was placed approximately 3 feet from the end connection of the bar joists. A second bundle of decking, weighing the same, was hoisted and placed on the same bar joist as the first bundle, approximately 8 feet from the end connection of the bar joist. As the second bundle of decking was placed on the bar joists, 4 bar joists started to “roll” and collapse a portion of the steel structure. CONTRIBUTING FACTORS: • Only one row of bridging had been partially installed at the time of the incident. • Four of the bar joists did not have any bridging installed. • Two of the bar joists only had one bolt installed at each end, and the other two bar joists had no bolts. • The connections of the bar joists had only received tack welds. • Decking bundles were placed further than 1 foot from the bar joist connections. HOW TO PREVENT RECURRENCE: • During the construction period, the employer placing a load on steel joists must ensure that the load is distributed so as not to exceed the carrying capacity of any steel joist. • No construction loads are allowed on the steel joists until all bridging is installed and anchored and all joist-bearing ends are attached. • The weight of a bundle of joist bridging must not exceed a total of 1,000 pounds (454 kg). A bundle of joist bridging must be placed on a minimum of three steel joists that are secured at one end. The edge of the bridging bundle must be positioned within 1 foot (.30 m) of the secured end. • No bundle of decking may be placed on steel joists until all bridging has been installed and anchored and all joist bearing ends attached, unless all of the following OSHA Subpart R conditions are met: o The employer has first determined from a Qualified Person and documented in a site-specific erection plan that the structure or portion of the structure is capable of supporting the load; o The bundle of decking is placed on a minimum of three steel joists; o The joists supporting the bundle of decking are attached at both ends; o At least one row of bridging is installed and anchored; o The total weight of the bundle of decking does not exceed 4,000 pounds (1816 kg); and o The edge of the construction load must be placed within 1 foot (.30 m) of the bearing surface of the joist end.


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