It wasn't just docks that used hydraulic mains for power. Best Beloved recounts a tale from his time as an apprentice in the railway works at Wolverton. Some of the heavier presses used hydraulic power, and the mains ran under the ground throughout the works complex. While on their lunch break one day, a main apparently fractured. Luckily, no-one was seriously injured, but the burst happened under some of the roads in the workshops making wagons. All kinds of debris rained down over quite a large area for some time, several wagons were damaged beyond repair, and a wagon, that had been sited right over the fracture, was allegedly completely vapourised.
A wonder of Victorian ingenuity and engineering.