Tri shelving Longspan Shelving Storage Shelving Solutions Tri-Shelving systems are ideal Solution for Mobile, Media, Archive, Medical & Office Environments, Bay Loading 450-500kg, Shelf Loading 100kg (UDL), Polyester Powder Coated. Advantage: Open (braced) and closed (back clad) bay options. Duplex shelves for lateral file storage available in 900, 1000, 1100 and 1200 mm widths. Quick and easy to assemble. Self-assembly components available.