90 SILOS: CONSTRUCTION AND SERVICE 



In the use of any material the possibility of destruction in 

 time, by natural agencies, such as decay or corrosion, should 

 be considered. The probable length of life of all parts should 

 be taken into consideration, and that which will probably 

 give out first should be planned with the largest factor of 

 safety. Thus in building a structure of any kind it should be 

 built so that each part will last as nearly as possible the same 

 length of time as every other, and when it does submit to the 

 agencies of time it should, like the "One-Horse Shay," all fail 

 in a day. 



Splicing and Welding. The method of splicing materials 

 should receive careful attention in order to make them as 

 strong as other parts. Pieces of steel in concrete or mortar 

 should hook into each other if the steel is smooth. The hooks 

 should, of course, be thoroughly imbedded in the masonry. 

 If twisted, corrugated, or other special reinforcing material is 

 used, the ends should extend past each other a distance equal 

 to at least 18 diameters of the material. Welding should be 

 avoided where possible, as in general it is difficult to make sure 

 that a forge weld is perfect. 



However, in cases of anchor rods, eye bolts, or similar 

 parts, the hooks or eyes should, if possible, be welded, because 

 the strength would then depend not only upon the stiffness of 

 the material in the hook or eye, but also upon the strength of 

 the weld. Hooked portions of any material should be 

 welded unless the steel is held firmly by being imbedded in 

 masonry. 



SPECIFICATIONS FOR STEEL 



Ordinary steel rods or wires do very well for silo building, 

 and can be depended upon to withstand a pull of about 12,000 

 pounds per square inch. Where steel is bought especially for 

 this purpose it is best to buy reasonably high-carbon steel or 



