This Standard sets out requirements and provides data for-(a) calculating the working loads on buried vitrified clay pipes due to-(i) materials covering the pipes; and(ii) superimposed loads; and(b) selection of the crushing strength class for combinations of installation condition, support type, working load and factor of safety.AS 1741 specifies the minimum crushing load for each nominal size and crushing strength class of vitrified clay pipes.In addition, the Standard classifies installation conditions and support types and specifies requirements, including compaction, for the embedment.