AbstractThe mechanical design of hot turbine blading has two main phases: (i) optimization, which yields the choice of material, number of blades, and general configuration, and (ii) detailed design of the particular features of the blades. The first phase makes use of the data available, which are usually limited, to provide an outline mechanical assessment of commercial viability. At this stage maximization of the lifetime to failure is considered in terms of the temperature and stress at each radial position; in the second phase failure modes are considered in more detail. The methods used in both stages are discussed, with emphasis on material and manufacture, taking as an example the blading in civil aircraft gas turbines. Particular attention is paid to the problems of designing with single-crystal cast superalloys.MST/222