A concrete slab may be prefabricated (precast), or constructed on site. The Amish have become popular builders of portable, modular and partially prefabricated garages. The girders being of equal length, it is ideal for use in prefabricated modular bridges. Khrushchev had prefabricated reinforced concrete used, greatly speeding up construction. The arch was assembled of 142 prefabricated stainless steel sections. It has a wide range of other uses including sculpture and prefabricated building components. The prosthetic compounds, abutments, are already prefabricated. CLT panels are prefabricated and can therefore speed up building time. Solitaire Homes has established a factory for producing prefabricated homes. Given the difficult topographic and climatic conditions, construction units were prefabricated. Shop drawings are typically required for prefabricated components. Extensive use of prefabricated components helped to speed up the construction process. It consisted of 245 pieces of separate prefabricated steel work. A large part of the construction was prefabricated. It included transportation, services and a manufacturing plant for prefabricated houses.