PURLIN SupaPurlin is a computer program for the analysis and design of SupaCee purlins. The sections can be designed with or without roof sheeting attached. SupaZed sections with roof sheeting can also be designed by modeling the section as an equivalent SupaCee section. The section to be designed is chosen from a library of standard sections. The user can select purlin configurations from one to twelve spans with cantilevers at either or both ends. Purlin systems with two or more spans can be lapped or unlapped. In addition, up to three rows of bridging can be included in each span. The effects of load height and restraint caused by roof sheeting on flexural-torsional buckling are also taken into account. The structure can be analysed for different combinations of point and uniformly distributed load and for different axial loads in each span. Strength limit state design load capacities for section moment capacity, flexural-torsional buckling moment capacity, distortional buckling moment capacity, shear capacity, combined moment and shear capacity, bearing capacity, combined moment and bearing capacity, axial tension and compression capacity, combined axial load and moment capacity, and connection capacity are calculated. The direct strength method can also be used to calculate the load capacity. A serviceability limit state design load capacity is also calculated. The results are displayed on the screen as a formatted report and can be saved to a file. Program PURLIN The program PURLIN is an alternative version of SupaPurlin which allows the user to design the following section types:- • Lipped Channel • Unlipped Channel • Lipped Zed • Unlipped Zed • Lipped Hat (vertical webs) • Unlipped Hat (vertical webs) Program PURLIN also allows the design of back to back and boxed channels (lipped and unlipped). In addition, PURLIN also displays the effective width calculations in detail in the report. In program PURLIN, the section properties are stored in library files (PRO) located in the program directory. These files can be edited by the user so that new sections can be added.