I love these old photos, interesting to see how steam engines were replaced with these early electric motors. Most of them in the photos look like they were for water pumping.
Actually it's the other way around Philip ..... they were not for pumping water, but rather for generating electricity in what is called a Hydro-Electric mode of operation, whereby the latent energy of water stored in reservoirs is run through a turbine to spin the generator. I would guess that there are not that many examples of this form of generation common in the UK, but it is very common here in the US, especially in the western US because elevation of source and gravity is the key.
Love old photos like this and would appreciate more of the same!