Hi pf, I know that the stream turbine blades are twisted in design so that when steam is forced across the face there is a torque exerted on the turbine. If you look closely at the blades then they are roughly at a 45 degree angle to the oncoming steam which means a component of the force from the steam will provide torque. What I don't understand is the problem with the following design. Imagine no twist in the blades at all. The blades are attached so that if you look at the turbine head on you are looking at each blade directly sideways on. You then blast steam right at the very bottom of the turbine from sideways on so that the steam hits the face of the blades exactly perpendicular to their surface. Surely then you get the maximum possible component from the force of the steam? Why don't they do this?