OpenBridge Modeler – Help ProStructures Steel ModelingSteel Connections Substation Gallery Double Frame Cap Creating a Double Frame Cap Creating a Double Frame Cap To use this Substation Gallery tool to create a connection, follow this procedure. Select from the Substation Gallery. The Double Frame Cap dialog opens. Select an A Frame or Trestle leg. Either: Specify the connection parameters. Load a Template. Optional: If you loaded a template, you may modify the parameters as necessary. Click OK.