Prefabricated arches for small and medium scale greenhouse tunnels

摘要

refabricated arc-shaped arches (hoops) 1 destined for forming small- and medium-scale greenhouse tunnels. They are composed of the section 1 extending over the soil, the section 2 laying onto the soil, and the section 3 introduced into the soil. There is no need of skilled staffs or adequate machine to set in position the arches, which are liable to from strong and elegant greenhouses. The arches are durable and easily stored; they preserve their shape for further use, without polluting the environment.