LIFT BRIDGE OVER THE MURRAY AT SWAN HILL. XCV. 
of 1’ 8” above summer level, supporting two wrought-iron cylinders 
6’ diameter, connected with stiff wrought iron diaphragm bracing, 
so designed as to ensure pier acting asa whole. The cylinders 
are filled with concrete composed of five parts of 24” granite, two 
parts of sand and one part of Portland cement, richer concrete 
being used in the top and bottom of cylinders. The maximum 
pressure on the rock foundation with bridge fully loaded and 
neglecting any assistance from flotation being 4} tons per square 
foot 
_ The superstructure of lift span is similar to that adopted for 
the Tocumwal and Wilcannia bridges, the two steel main girders 
are 4’ 2” deep with top and bottom boom of trough section, formed 
of two angle bars riveted to 12’ x 4s” plates, the web consisting 
of vertical struts at ends and channel bars set to an angle of 45°. 
The steel web plate cross girders are placed at the apices, being 
carried on steel saddle plates riveted to bottom boom of main 
girder, two main girders being connected by a lateral system of 
adjustable diagonal flat bars. The side spans are of the 1893 
Standard type design, a description of which has already been 
given by the author in a paper read before this Section.? 
The four hollow towers (similar in general design to Tocumwal 
bridge) 3’ square, 40’ 2” long, are formed each of four vertical 
angle irons, braced with horizontal T iron and flat diagonal tie 
bars. The base of each tower is continued 6’ down inside wrought 
iron cylinder and bolted to four 6’ lengths of vertical angle iron, 
these vertical angle irons being bolted to diaphragm plates, which 
in turn are connected to the shell of cylinder by 3” x 2” x 3” angle 
irons with }” rivets, the base of the tower being then filled in with 
Concrete to the level of cylinder caps; the bolt holes in the 6’ 
Vertical angle irons and in the diaphragm plates were drilled om 
situ, thus permitting of the adjusting of the slight difference in 
the sinking of cylinders, which amounted to }” in the centres of 
the upstream and 3%,” in the centres of the downstream cylinders. 
1 Journ. Roy. Soc. N. S. Wales, Vol. ¥x1X., 1895. 
