Concrete Silos 



127 



Perfection Concrete Stave Silo. This system is 

 controlled by the Perfection Concrete Stave Silo Com- 

 pany, Des Moines, Iowa, and the outfit with which 

 the staves are made is sold outright to manufacturers. 

 These staves can be used for structures from 10 to 

 36 feet in diameter and up to 60 feet high. 



The staves are 28 inches long, 10 inches wide, 2% 

 inches in thickness, and are made in steel forms with 

 a wet mix, waterproofed and made impervious by the 

 addition of 10 per cent of the weight of cement in 

 hydrated lime. The staves are made concave on the 

 edges and on the ends, and when they are assembled 

 in the silo the space which is thus formed is filled with 

 mortar. 



The company also manufactures for use on its silos 

 a malleable iron door frame and an all-steel door with 

 steel ladder combina- 

 tion. The door sys- 

 tem is continuous 

 from the foundation 

 to roof, the frame 

 occupying a space of 

 only 4 inches between 

 doors. Each door 

 opening is 23x25 in. 



In Constructing the 



silo, one of the malle- 



able iron door frames 



is placed upon a circular concrete foundation, and half 



staves (that is, 14 inches in length by 10 inches in 



width by 2% inches in thickness), are plaped on the 



foundation, in the channel on either side of the 



malleable iron door frame; then a full length stave is 



The Per fec Silo Steel Door in 



steel ladder sys " 



