London Hydraulic Power Company
The London Hydraulic Power Company was set up by an Act of Parliament in 1883 to install a hydraulic power network of high-pressure cast iron water mains under London. It was the successor to the Steam Wharf and Warehouse Company, founded in 1871 by Edward B Ellington. The network covered an area mostly north of the Thames from Hyde Park in the west to Docklands in the east.
The system was used as a cleaner and more compact alternative to steam engines, to power workshop machinery, lifts, cranes, theatre machinery, and the backup mechanism of Tower Bridge. It was also used to supply fire hydrants, mostly those inside buildings. The water, pumped straight from the Thames, was heated in winter to prevent freezing.
- Falcon Wharf Pumping Station next to Blackfriars Bridge (this was the first)
- Renforth Pump House (Rotherhithe, Canada Water) (opened in 1904), using the defunct Tower Subway to carry pipes under the Thames 
- Wapping Hydraulic Pumping Station (est. 1890) (closed in 1977 and the last to be used) 
- City Road Basin on the Regent's Canal in Islington
- Pimlico along Grosvenor Road (79 Grosvenor Rd, Westminster, London SW1V 3, UK).
Short-term storage was provided by hydraulic accumulators, which were large vertical pistons loaded with heavy weights.
From about 1904, business began to decline as electric power became more popular. The company began to replace its steam engines with electric motors from 1923. At its peak, the network consisted of 180 miles (290 km) of pipes, and the total power output was about 7,000 horsepower (5.2 MW).
The system closed in 1977. The company, as a UK statutory authority, had the legal right to dig up the public highways to install and maintain its pipe network. This made it attractive to Mercury Communications (a subsidiary of Cable & Wireless) who bought the company and used the pipes as telecommunications ducts. Wapping Hydraulic Power Station, the last of the five to close, is now an arts centre and restaurant.
- Hydraulic power in London from Subterranea Britannica including photographs.
- London Hydraulic Power A look at the system in 1936
- "Hydraulic Power Company". Vauxhall Society. Archived from the original on 27 January 2008.