London's Hydraulic Age

Late nineteenth century London was a mixture of old and new:  there were horse-drawn carriages, but also, many of the wonders of the industrial age.  The benefits of the industrial age and steam engines had changed the way that people lived, how factories were powered, and how efficiently factories worked, but there were limits to how much mechanization could be used in the city.

There were elevators in large buildings, giant mechanized printing presses, water pumps, and heavy machinery of all types…but how did they power them?  The ultimate source of power for all of these were steam engines, but many businesses didn’t want a noisy steam engine on site, with constant wagon loads of dusty coal queuing up to unload.

Take, for example, the Savoy Hotel on the Strand.  It is hard to imagine having Peach Melba prepared by Auguste Escoffier and overseen by hotel manager, César Ritz, while the entire hotel rattled from a noisy steam engine in the basement.  The Savoy needed something to operate the “lifts” and the adjacent Savoy Theatre needed something to open the massive curtains for the debut of Gilbert and Sullivan’s Mikado.

If only there were some way of piping in power as easily as water or gas could be brought in.

Actually, there literally was a way!  Buried beneath the streets of London were cast-iron pipes that carried water under high pressure—as much as 800 psi.  In fact, there were a total of 180 miles of such pipes connecting businesses to the pumping stations operated by the London Hydraulic Power Company.   This was a for-profit utility company, chartered by Parliament, that sold shares, issued bonds, and charged customers for the service.  The rates customers paid were calculated by meters that measured the pressure and quantity of water used.

To make the system work, five pumping stations were scattered across the city, located—if possible—near a canal or the Thames River, to accommodate coal-bearing barges.  Inside the pumping stations, massive steam engines operated large, horizontal three-cylinder water pumps that sent filtered water to accumulators.  Built vertically as tall as three stories, the accumulators were pistons with 50 tons of iron weights on top to maintain and regulate the pressure.

But how exactly did that pressurized water become useful mechanical energy at the point of service?

The answer lies in the clever application of hydraulic actuators and motors—devices that converted the water’s pressure into motion.  The most common of these were hydraulic cylinders, essentially long, reinforced tubes with internal pistons.  When the 800-psi water entered the cylinder, it pushed the piston forward, creating linear motion.  This mechanism was the backbone of many installations across London.  In grand hotels like the Savoy, hydraulic cylinders smoothly lifted guests in early elevators.  In theaters, the same principle raised and lowered entire sections of the stage, including trapdoors and orchestra pits.

Other applications required rotational movement, which was achieved using hydraulic motors.  These devices allowed pressurized water to spin a rotor, generating torque and rotary motion. This kind of setup was used in more complex mechanisms—like revolving theater stages, winches, and shop display turntables.

London’s docklands and warehouses benefited particularly from hydraulic cranes, which used both linear and rotary hydraulic components to lift and swing heavy cargo with precision.  The power was reliable, consistent, and clean—an enormous advantage in the smoke-clogged industrial city.

Unlike electrical systems, which transmit energy via electrons, hydraulic power transmitted energy via fluid force and volume.  The water—after doing its work—was usually discharged into drains, not recirculated, which made the system simple, though not especially water-efficient by modern standards.

The brilliance of this system was its modularity: a single pressure line could run an elevator in a hotel, open or close the curtain in a theater, open a heavy bank vault door, or run a printing press in Fleet Street.  All the end user needed was the right hydraulic actuator.

In short, Victorian London didn’t just rely on steam and gaslight—it ran on water that was pumped and pressurized beneath its streets.  It was a quiet force—almost invisible, yet utterly vital to the daily rhythm of the modern city.  And since the system worked so well, it was copied in other large cities:  Birmingham, Glasgow, Antwerp, Geneva, Melbourne, and Buenos Aires.  Even New York briefly experimented with such a system.

Over the years, electric motors replaced many of the functions of hydraulic power.  Electric elevators, for example, moved faster and more smoothly than hydraulic elevators.  The changeover to electric motors was slow, in part, because hydraulic systems are mechanically simple:  hydraulics had no spark risk, had fewer moving parts, and produced high torque at low speeds.  Thousands of buildings had lifts, hoists, and theatrical or industrial machinery, that was built around hydraulic actuation, that was installed from the 1880s to the 1930s. In many cases, it was cheaper to keep using hydraulic power than to replace the equipment.  Converting these systems to electric motors would have required extensive retrofitting which would have been both expensive and  structurally invasive, so most businesses held off as long as possible.

Eventually, the London Hydraulic Power Company just could not afford to maintain the heavy equipment with so few customers and so it ceased operation in 1977.  All that remains is the Wapping Hydraulic Power Station, which is the last of the pumping stations.

London’s Hydraulic Age, so brief that few even noticed it, was over.