Spain's national network of silos and granaries: architectural and technological change over time

Aim of study: To analyse the 670 silos in Spain's NNSG (National Network of Silos and Granaries), along with the changes in typologies and degree of mechanisation taking place over time. Area of study: Spain. Material and methods: Research began in 2014, collecting NNSG grain storage data across Spain further to the methodology developed by the authors. In a first stage the information was gathered from the FEGA's general archives in Madrid and the archives of the departments of agriculture in the 13 regions where silos were built. In the second stage of the study, 665 silos were explored in situ. Photographs were taken and information was gathered on their characteristics (general features; architectural features; technological facilities). Main results: This paper discusses the architectural and typological changes taking place over time, from the earliest small, local, richly adorned brick silos to larger, more modern and austere reinforced concrete structures. The machinery with which they are fitted is also addressed, with the progression from basic grain storage to more sophisticated equipment designed to clean, refrigerate or disinfect the grain. Some facilities were used exclusively to select and condition seed for subsequent sowing. The most modern structures, known as macrosilos, are highly mechanised affairs. Research highlights: Spain's national network of silos and granaries was 41 years in the building. The inventory of the 665 existing silos identified 20 types or subtypes. Early richly adorned units gradually gave way to more austere, functional structures. The machinery in place in silos varied with type/purpose and period of construction.