200 



FRAMEWORK 



Trusses supported directly on masonry walls have one end sup- 

 ported on sliding plates for spans up to about 70 feet; for greater 

 lengths of span one end should be placed on rollers, or should be hung 

 on a rocker. Trusses for mill buildings should be made with riveted 

 rather than with pin connections, on account of the greater rigidity of 

 the riveted structure. The complete shop drawings of a truss for the 

 machine shop at the University of Illinois, are shown in Fig. 95. This 

 truss is more completely detailed than is customary in most bridge 

 shops. The practice in many shops is to sketch the truss, giving main 

 dimensions, number of rivets and lengths of members, depending on the 



FIG. 96. 



