Pump in its prime

Of all the great feats of Victorian engineering, one of the greatest is mostly invisible. The sewerage works of London, built in the 1850s under the direction of Joseph Bazalgette, comprise a network of more than 1,000 miles of pipes under the city, incorporating many of the Thames' tributaries.

They not only enabled the city's expansion into the metropolis we know today — Bazalgette carefully calculated the size of piping to meet the demand of the city of the day, then doubled every diameter — they also saved millions of lives, preventing the contamination of drinking water by sewage that had led to devastating cholera epidemics in the East End and Soho. The sewers are the largest part of the network but essential to their operation are four pumping stations at Crossness, south-east London, Erith, Kent, Abbey Mills, east London and Chelsea, where vast steam engines pumped the sewage into holding reservoirs before being released into the Thames.

These pump houses, long superceded by other systems, were marvels of Victorian craftsmanship; the engines were towering constructions of polished iron and brass, set within traceries of wrought iron.

The architectural historian Nikolaus Pevsner called the Crossness pumping station 'a masterpiece of engineering — a Victorian cathedral of ironwork'. But the engines were stilled more than 50 years ago and rust and nature took over.