Walking on History: Surprising Secrets of Manholes

Historic manhole covers, embedded in pavements and roads across the country, often hide infrastructure systems deep below our streets.

Many date from the 19th and early 20th century when Britain’s population was expanding rapidly. Utility companies offering services such as water and sewage, gas and electricity, telegraph and telephones, installed them as part of the infrastructure that enabled growth and connectivity in our towns and cities.

Manhole covers are access points to a hidden world of pipes, wires, conduits and tunnels. Here are 13 early examples that help tell the story of Britain’s booming urbanisation.

How long have manhole covers been around?

The first ‘manholes’ are thought to have been introduced by Romans, who were extraordinary innovators in terms of sanitation. Then, slabs of stone or wood would have provided access to stone-covered channels carrying water or sewage.

The principles changed little over the centuries. The style of manholes we are familiar with today have a removable cast-iron cover, at least the width of a worker’s shoulders, concealing an underground shaft.

The Victorian and Edwardian periods they originate from saw enormous population growth. From nearly 9 million in England and Wales according to the 1801 census, the population grew to 32.5 million by 1901. In the same period, London grew from 1.1 million to 6.7 million as people flooded into the capital, especially from rural areas, in search of work.

Many manholes, whose patterns and studs are to prevent slippage of pedestrians, vehicles and horses, are marked with the name of the foundry that cast them, usually in raised letters.

Occasionally manholes proudly carry the name of the business, organisation or authority supplying the service. Others have no lettering, just patterns, or have words so worn by decades of passing pedestrian or vehicle traffic that they are illegible.

Old manholes, including their frame, can weigh anything from 50 to 200 kilos.

Solving the sewage problem

The manhole pictured is evidence of the seismic shift in attitude towards sewage disposal from the mid-19th century.

The concept of universal access to clean water is mostly a product of those decades too. During and after the Industrial Revolution, which began 100 years earlier, water sources became increasingly polluted, leading to fatal diseases such as cholera.

In London, raw sewage seeped from decrepit sewers into the River Thames, turning it into a stinking open sewer. Tens of thousands of Londoners died in cholera epidemics over the decades.

The increasingly widespread use of the new flushing toilets exacerbated the problem, overwhelming London cesspits and causing more waste to flow into the River Thames, leading to the ‘Great Stink’ of 1858.

The need to safely dispose of sewage became a government priority. An Act was passed allowing Sir Joseph Bazalgette to create a new sewage system for London. When completed in the mid-1870s, the sewage network’s enclosed brick tunnels, which captured both sewage and rainwater, virtually eliminated cholera.

London led the way for the rest of the country. From the mid-19th century onwards, most of the larger cities began to construct their own sewage systems, with the 1875 Public Health Act empowering local authorities to provide clean water supplies and treat sewage before its disposal.

Gas transformed domestic and working lives

The development of gaslighting in the Victorian era – more efficient and cheaper than oil – had a profound effect on the domestic and working lives of the British population. Gaslighting from coal had been invented in the 1790s, but it was not until the early years of the 19th century that it started to spread nationally. The first buildings to use gas for lighting were northern textile mills, until that point lit by candles or whale oil (as were homes). The first gas street lighting was in London’s Pall Mall in 1807.

A few years later, by the 1820s, almost all towns and cities in the country had their own gasworks. Gas was used mostly for street lighting, making streets safer, and for public buildings such as theatres. Brightly-lit shops could display their goods and stay open after dark. By the last quarter of the 19th century, most working families could afford to have gas lighting in their homes.

Cooking by gas was slow to gain acceptance, but displays at the Great Exhibition in Hyde Park in 1851 popularised it for wealthier families. The use of gas cookers becoming widespread by the 1920s, boosted by the introduction of rental schemes and pre-payment meters. Gas-heated hot water in the home only became safe and efficient in the 20th century with the introduction of gas heaters with a flue and a pilot light for automatic ignition.

Electricity becomes more popular than gas

In 1831, Michael Faraday’s discovery of the relationship between electricity and magnetism was key in introducing a powerful new technology. The socially transforming effect of electricity in the latter part of the 19th century is viewed by many as the second phase of the Industrial Revolution.

Outdoor lighting for public spaces and large buildings was the first practical use of electricity from the 1870s, but this arc lighting was too powerful for domestic use. It was not until Britain’s Joseph Swan and America’s Thomas Edison invented the incandescent light bulb around the 1880s, ancestor of the ones that dominated until recently, that electric lighting became available in the home and was soon more popular than gas. The pair later joined forces to produce commercially viable light bulbs.

Early electricity generating stations could only supply current over short distances. This resulted in small localised plants for many municipal authorities providing electricity for public lighting, industrial sites, and domestic use. Private institutions and businesses, such as factories and mines, rail and tram companies, and large country houses, often built their own generating stations. 

It is thought there were over 450 electricity suppliers in Britain in the early 20th century.  The Electricity Act of 1926 standardised the supply of electricity and, by 1935, established the network of major power stations and distribution lines that became known as the National Grid.

By the 1930s, new urban homes in Britain were being built connected to electricity grids, while by the end of the decade two-thirds of homes were fully wired up.

Electric telegraph revolutionised communication

The idea of communicating over long distances via electricity, rather than by messenger or semaphore systems such as flags or beacons, dates to the 18th century. But the electric telegraph – devised to send text messages more rapidly than written ones, using a current to move magnetic needles to transmit the message in code, translated by a skilled operator – only became a practical reality from the mid-1830s when it was developed in parallel with the railways to control signalling.

The technology evolved and rapidly spread. Transmitted electronically from post offices, railway stations and telegraph offices, telegrams revolutionised the sending of instant personal messages, news and business information. Also known as a cable or wire, they were sent nationally at first, and then crossed oceans and continents via submarine telegraph cables – the first laid under the English Channel in 1851.

The technology had a widespread social and economic impact and is the historic forerunner of today’s instant messaging systems.

Britain gets the telephone

The electric telegraph laid the foundation for the telephone, first demonstrated to Queen Victoria by inventor Alexander Graham Bell in 1878. Many local telephone companies were established shortly after, with telephone exchanges constructed throughout Britain.

The Post Office, established in 1878, had the electric telegraph monopoly and it saw the expansion of private telephone companies as a threat to its business. It challenged them in the courts. A court ruling in 1880 determined that the telephone was indeed legally a telegraph. From this point, telephone companies could only continue trading if licensed by the Post Office.

1912 saw nationalisation, which meant a unified telephone system throughout most of Britain, with telephones able to be installed in homes. But only the better-off could afford their own. The majority of people continued to use public phone boxes until the 1950s and 1960s, after which time technological improvements gradually made home telephones widely available.

Written by Nicky Hughes

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Further reading

• Exeter Foundry, a history
• Laurence’s Walks
• Ian visits
• The Street Heritage Research Group
• Spending a Penny: an Exploration of England’s Public Toilets

The Story of London’s Sewer System

Secret Worlds Hidden Beneath Surface Structures