be provided immediately in front of the first rotor blade row 7 the arrangement shown in fig5 corresponds to that in fig1 with the difference that in this case two or more partial admission stages 16 act before the swirl cascade 4 a partial admission guide cascade 17 is provided between each pair of partial admission rotor wheels 16 such an arrangement is particularly suitable for the admission of very small inlet volume flows so that partial admission can be provided over several stages with subsequent equalization over the whole periphery in this connection the design shown in fig6 must also be considered the only difference from the previous figure is the arrangement selected upstream of the swirl cascade 4 in this case a 34 curtis stage 34 18 19 is involved reference should be made inter alia to a stodola dampf und gasturbinen fifth edition berlin 1922 p 496 ff and w traupel thermische turbomaschinen vol 1 third edition berlin 1977 p 152 ff with respect to the technical features of the 34 curtis stage 34 18 19 fig7 shows a different type in which the impulse wheels 20 21 and 22 used in the turbine do not have any diameter difference relative to the control stage 2 3 located upstream the intermediate space 23 is dimensioned in such a way that the swirl flow generated by the swirl cascade 4 is not impermissibly reduced before admission to the full admission impulse rows 20 21 and 22 fig8 shows the plate 5 and the swirl cascade 4 in an axial view the impulse type swirl cascade 4 is reduced to an admission arc zone 24 so.