316 



STEEL BINS. 



CHAP. VIII. 



Strength of Buckle Plates. The safe load for a buckle plate with buckles placed up, is approxi- 

 mately given by the formula 



W = 4f-R-t (36) 



where W = total safe uniform load in Ib. per inch of width of plate; 

 / = safe unit stress in Ib. per sq. in.; 

 R = depth of buckle in in.; 

 t = thickness of plate in in. 



Where buckle plates are riveted and the buckle placed down the safe load is from 3 to 4 times 

 that given above. 



TYPES OF BINS. The most common types are (i) the suspension bunker, (2) the hopper 

 bin, and (3) the circular bin. 



Suspension Bunkers. Suspension bunkers are made by suspending a steel framework from 

 two side members, the weight of the filling causing the sides to assume the curve of an equilibrium 

 polygon. The stresses in the plates of a true suspension bunker are pure tensile stresses. Steel 

 suspension bunkers are commonly lined with a concrete lining about 1 1 to 35 in. thick, reinforced 

 with wire fabric, to protect the metal of the bin. 



........... -65-0" .......... 



llevarthn 

 FIG. 1 6. COAL BUNKERS, RAPID TRANSIT SUBWAY, NEW YORK, N. Y. 



Hopper Bins. Hopper bins may be made of timber, steel, or reinforced concrete. A steel 

 coke and stone bin, erected by the Lacka wanna Steel Company, is shown in Fig. 12. These bins 

 were divided into panels 12 ft. 6 in. center to center, with double partitions at each panel point, 

 leaving a clear length of 1 1 ft. 6 in. The bins are lined throughout- with f in. plates. All rivets 

 in the floor are countersunk. The gates at the bottom of the bin are cylindrical and are revolved 





