I'm afraid that this is a bit of a badly-curated wander, where I mostly just popped out to find out a little of the history of Underfall Yard and poke around the various open workshops, and, in hindsight, really didn't take pictures in any kind of coherent order. So there's a lot of pictures, but they don't really tell the story that, in hindsight, I seem to have been trying to tell, of the unusual electrical substation in Avon Crescent, the Bristol Electricity that predates the National Grid but is still in use, the history of the hydraulic power house... It's a bit of a mess.
But I suppose sometimes these wanders—always chronologically presented in the order I walked and took photos—simply will sometimes be a bit of a mess. Let's hope you still get something out of it, anyway...
...is worth a thousand words. As you can see from the map, hydraulic power from the accumulator can be used to power things all around the harbour, including to swing Prince Street Bridge, about a mile away. Impressive.