104 Concrete Silos 



legs of the scaffold. The planks to form the runway 

 on the outside should be of 2x8 material, and in a silo 

 16 feet in diameter should be 8 feet long. If the silo 

 is to be 36 or 37 feet high, it will be necessary to make 

 five platforms. It is convenient to have the top plat- 

 form come within 3 or 4 feet of the top of the silo, since 

 the work of raising the 2x4's and nailing the plate on 

 top is done from this platform. 



The following table shows dimensions of plate seg- 

 ments and number required for silos of different sizes : 



Inside 

 diameter of 



silo 



12 feet 

 14 feet 

 16 feet 

 ]8 feet 



The plate is sawed from Ix6-inch material, which 

 should be either fir or cypress. The plan of making 

 the pattern is shown in the plate. A piece of the 6-inch 

 board should be securely fastened to a work bench or 

 barn floor, 

 and after the U V B / 



distance C-D JLUu-^" 

 has been de- 

 t e r m i n e d 

 from the 



table, these Detail of Plate. 



points should Be carefully marked upon one edge of the 

 board. Locate the center of the desired curve by the 

 use of a sweep, through which two small nails have been 

 driven, the distance between them being exactly the in- 

 side radius of the silo. Using C and D as centers, de- 

 scribe intersecting arcs, thus locating the desired center. 

 Drive one nail of the sweep at the intersection of these 



