A bunker type silo with portable sections has been developed at Iowa State College. It ws first designed for experimental work with silage feeding and handling. Its features, however, have possibilities for farm application such as temporary location on an existing feeding floor or expansion or reduction of silo width to adjust for changes in numbers of animals fed from year to year.
Curry, Norval H. and Armstrong, Ray E.
"New Possibilities in Portable Bunker Silos,"
Iowa Farm Science: Vol. 11
, Article 2.
Available at: https://lib.dr.iastate.edu/farmscience/vol11/iss2/2