Steam turbine designs

I've posted a few times before about steam turbines, here, here, and here.  One of the things I find fascinating about steam turbines is how vast the variety is among them, depending upon the application.

• Steam turbines that are used for marine propulsion will have stages to turn them in the reverse direction, and a separate astern steam throttle valve.
• Steam turbines that are used in power plants for generation of electrical power come in a stunning variety of shapes, sizes and designs.
• Steam turbines that are used provide cogeneration for other processes are often very compex and unique.
• Turbines can be designed for various operating pressures and outputs, making each design slightly different and interesting in its own way.

Below: An early steam turbine diagram from 1905 for shipboard use.  The astern steam throttle is at top left. These two stages turn the shaft in the opposite direction than the seven forward stages.  Only two stages are used for astern movement, because it is not used often and so efficiency is not necessary.