Keywords: Trench safety - attaching guide line (9247872029).jpg Image of instructor demonstrating the correct method of attaching the guide line to the trench box https //www flickr com/photos/niosh/9247872029/ Trench safety - attaching guide line 2010-03-16 16 43 https //www flickr com/people/25069384 N03 National Institute for Occupational Safety and Health NIOSH from USA PD-USGov NIOSH http //flickr com/photos/25069384 N03/9247872029 2015-04-23 18 51 46 United States Government Work Construction Safety Shoring Work Workplace National Institute for Occupational Safety and Health |