Keywords: Trusses LeBlanc Construction.jpg en A set of trusses is assembled on the ground and then lifted by crane into place Workers wearing personal fall arrest systems appropriately attached to already-secured parts of the frame then secure this set of trusses to the frame 2012-07-24 10 52 15 http //www flickr com/photos/niosh/9256400586/ National Institute for Occupational Safety and Health PD-USGov Uploaded with UploadWizard Roof construction Framing building Mobile cranes in the United States Peterbilt |