Using projection micro-stereolithography, microlattices can be created using forms much like trusses and girders. The design of this type of roof is achieved using rafters, roof trusses or purlins. Cast-iron was used for the roof trusses and floor beams. Its roof is suspended by exterior steel trusses. Cantilevers can also be constructed with trusses or slabs. Some systems combine stringers and supports into steel or aluminum trusses. Most of the roofing was traditional wooden trusses covered with metallic sheets. The exposed belt trusses serve aesthetic and structural purposes. The arch is two-ribbed, fabricated from large steel trusses. Werner Sobek designed the roof, which is held in place by 48 -long trusses. After this, 237-metre long steel trusses were welded to the gates. More advanced rigs can include working with pulleys, steel cable or trusses. Common bearing type connections include&colon; shear tabs, beam supports, gusset plates in trusses. The spacecraft was composed of three decks supported by trusses and an arch. Presumably the earlier ceiling was a structure with wooden trusses.