Gas and steam-power stations with highly efficient gas turbines in tandem compound arrangement (gas and steam turbine drive together a generator on the same shaft) conquer the market - at Least in foreign countries. Low investment costs, Little demand for space, high efficiencies and further advantages explain the boom. All manufacturers of large-scale gas turbines realized that with tandem compound arrangement a considerable increase in efficiency is feasible: the value of 60 percent net efficiency might be exceeded in the near future. The essay provides an overview of the highly efficient gas turbines and compares them as to their technical peculiarities.