On the construction of wrought iron lattice girders

Thomas Cargill
1864 Journal of the Franklin Institute  
Continued from page 21.) IN the examples given of the flanges of double lattice girders, the connecting medium between the tension and compression bars composing the web, and the plates which are a portion of the flanges, has been supposed to consist of two pairs of angle-irons, riveted longitudinally to the plates throughout the whole length of the girder. In some instances tee-irons are employed as the means of attachment, each pair of longitudinal angle-irons being replaced by one tee-lron.
more » ... he table of the tee-lron is riveted to the plates in the ordinary manner, and the bars of the web are attached to the tongue or rib, on the outside and inside successively. This substitution is well adapted for girders of small spans, but cannot be used with equal advantage in those of large dimensions. The riveting of the tee-lron through its table portion to the plates is better and more efficient than that of two angle-irons of the same sectional area. If we suppose the centres of the rivets to be the centres of resistance, the resultant of the forces in the former case will pass through the centre of gravity of the tee-iron, and the leverage will be reduced to a mere nothing. On the other
doi:10.1016/0016-0032(64)90399-0 fatcat:pn6i56prpzdq5b4qohqjtqj224