be parallel with the ground while the posts 104 and 120 remain plumb the cylindrical upper frame member 160 has a substantially horizontal axis and extends outwardly and horizontally from the vertical frame member upper end 168 the upper frame member 160 has an inner end 188 and an outer end 192 a cylindrical brace collar not shown concentric with the upper frame member axis may surround the outer end 192 and a cylindrical brace extension 196 which extends from the outer end 192 the purposes of the brace collar and brace extension 196 will be explained below the diagonal frame member 164 extends from the upper frame member outer end 192 to the vertical frame member lower end 172 preferably the vertical frame member 156 upper frame member 160 and diagonal frame member 164 are joined by welding the brace 144 further includes a triangular gusset plate 200 the gusset plate 200 is fixed within the triangular frame 152 and extends between the vertical frame member 156 upper frame member 160 and diagonal frame member 164 the gusset plate 200 provides support to the frame members 156 160 and 164 to prevent the frame from collapsing when put under strain preferably the gusset plate 200 is joined to the frame members 156 160 and 164 by welding the corner post brace 144 is fixed to the corner post 104 by a fastening device combination or a bolt 204 and a nut 208 the bolt 204 extends through the lower mounting bolt hole 176 of the brace 144 and through the corner post bolt hole 136 and is secured by the nut 208 the brace post brace 146 is fixed to the brace post 120 by a fastening device combination or a bolt 212 and a nut.