Silo, 2,120 CF, C/st, 12' x 23', Flour Silo, SSISilo, 2,120 CF, C/st, 12' x 23', Flour Silo, SSI. 60,000-pound Flour Silo manufactured by SSI ( Steel Structures,Perfect), rated for 2,120 cubic feet capacity. Measures 12' diameter x 23' high, mild steel construction, 10 gauge bottom and shell thickness. New in 1995.