78 
CONCRETE SILOS 
round rods are required between the 28-24-foot levels and also continuing 
up to and including the 12-foot level. From the 12-foot level up to 
the top, 3^-inch round rods are required between each two courses. 
The reinforcing is commonly laid in the mortar between the courses 
of block, the strength of the mortar and the downward pressure of the 
blocks above being depended upon to keep the rods in place 
Recesses for under loaded conditions. In the best practice, however, blocks 
Rod used which have a recess in the top face deep enough to ac- 
commodate the reinforcing rod. Recesses are generally put 
about two inches in from the outside of the block. 
Concrete jambs for the continuous doorways of concrete block silos 
may be made as shown on page 75, and faces of the jambs should be the 
Continuous ^^^^ those on the continuous door jambs of monolithic 
Doorways silos, as described on page 63. The jambs may be easily con- 
structed by the use of simple box molds, recesses being formed 
on the inside of the jambs by the use of 2x2-inch cleats. As the reinforc- 
ing rods are laid upon successive courses of blocks, they are cut off so that 
the ends will extend out far enough to be firmly fastened to the 3^-inch 
vertical rods to which the horizontal ladder rods are attached. These 
vertical rods should be located near the center of the jamb. The doors for 
the continuous doorway are the same as for the continuous doorways of 
monolithic silos, as described on page 64. 
Home-Made Blocks 
A number of farmers in various parts of the country have put up con- 
crete block silos with blocks made during spare time with a block machine, 
or a home-made mold. Good blocks can be made by either method, but 
the use of a machine quickens the work, and does it in a more uniform 
manner with the expenditure of a great deal less labor. 
For the benefit of those who may wish to manufacture silo blocks, 
with a machine designed for that purpose, the following list of manufac- 
Block turers, who exhibited their machines at recent Chicago Cement 
Machine Shows, is given. There are also a large number of other machines 
Manufac- on the market, capable of making good concrete silo blocks. 
turers Yv\\ information regarding these machines will be gladly given 
by any of the manufacturers listed below. 
Anchor Concrete Stone Co., Rock Rapids, Iowa. 
Ashland Steel Range & Mfg. Co., Ashland, Ohio. 
Barron & Harridge, Insurance Exchange Bldg., Chicago. 
Cement Machinery Co., Jackson, Mich. 
Century Cement Machine Co., Rochester, N. Y. 
The J. B. Foote Foundry Co., Fredericktown, Ohio. 
Hayden Automatic Block Machine Co., Columbus, Ohio. 
Hobbs Concrete Machinery Co., Detroit, Mich. 
Hurst Silo Co., 819 Exchange Ave., Chicago, 111. 
Ideal Concrete Machinery Co., Cincinnati, Ohio. 
Inman Concrete Block Machine Co., Beloit, Wis. 
Lansing Co., Lansing, Michigan. 
Miles Manufacturing Co., Jackson, Mich. 
