Abstract: A turbine installation comprises flow passage-defining means defining an inlet chamber and a runner chamber and including two juxtaposed interconnecting passages which connect the inlet chamber and the runner chamber and are disposed on opposite sides of an axial center plane, and spaced apart in an intermediate part of their length, a turbine runner rotatably mounted in said runner chamber, an electric generator disposed outside the flow passage-defining means, and an output mechanism extending through the space between the two interconnecting passages, and operatively connecting the runner to the generator.