Cast Iron Pipework: Victorian marvel, modern menace

Our country’s infrastructure is built on the shoulders of giants. Our daily blessings of clean, drinkable water on tap and indoor flushable toilets are only possible because of over a hundred years of development and some of the most imaginative and creative engineering minds to have existed. 

A recent job with our professional partners WRc in South Wales led me to investigate the origins of the development of the water and sewage system in the UK. It is quite staggering when you consider that many of our own homes and certainly much of the water and sewage system that we enjoy in the UK still contain much of the original cast iron pipework from the original Victorian system. 

Cast iron pipework was revolutionary in its day but can now cause significant problems to our network. Before discussing these issues, it is important to recognise just how developmentally significant cast iron pipework and the original sewage and water system were when it was developed in the 19th century.

A brief history of the development of the water and sewage system in the UK

The UK’s current sewage and water system were set up during the Victorian period. Prior to its development, water and sewage management was a piecemeal affair. Your socioeconomic status and geographical location determined how much you benefited from the scraps of infrastructure available in the UK.

At the beginning of the 19th century there was very little understanding of the causes of disease, and as such the connection between sewage and illnesses like cholera was not recognised. As such, the government spent more time worrying about getting water into urban areas than removing the resulting waste of human habitation.

victorian cast iron pipe
An example of Victorian cast iron pipework

Private companies such as the Lambeth Waterworks, the South London Waterworks Company and the Grand Central Waterworks Company were all well established by the 1820s. The Lambeth Waterworks company replaced their wooden pipes with cast iron pipework in 1802. Gravity sewer systems and storm drains were developed as towns grew into cities during the Industrial Revolution. 

Whilst water supply was not necessarily a problem in the capital, a Victorian’s experience of sewage provision depended on their economic status and geographical location. The rich often benefited the most, some even enjoying indoor plumbing by 1840. The sewage was untreated and fed into existing rivers. It often ran into water supplies, affecting areas where the working class lived. The poor often had to rely on public toilets and cesspools. All of this resulted in diseases such as cholera and typhoid running rife in working-class areas, and despite some scientific investigations into the causes of cholera (such as that conducted by Dr Snow in 1854), not much action was taken by the authorities

During the summer of 1858, the smell of sewage that filled the River Thames became so toxic and overpowering that those closest to the River became overcome. The MPs sitting in Parliament at the time could not work, prompting them to pass a law calling for a unified sewage system to be built in London. This “Great Stink” (as the event came to be known) led to the development of sewage systems across the UK. Typically, it was only when the sewage problem offended the rich that anything significant was done to address the problem!

Sir Joseph Bazalgette was the man tasked with transforming London’s sewage system. He had already submitted plans to that effect before the Great Stink, suffering several knockbacks as Parliament questioned how much the system was needed. After suffering the summer of 1858, even the MPs were convinced!

By 1870, the sewage system built by Bazalgette included over 13,500 miles of pipes and tunnels. It ensured that the sewage system did not contaminate the water supply in London. 

Cast iron pipework formed a substantial part of the water supply and sewage system. The system created in London virtually eradicated cholera outbreaks, leading to a recognition that germs in sewage caused disease. Other cities around the UK started rebuilding their own water and sewage systems in response. 

The development of the water and sewage system in the UK really did allow a huge improvement in the quality of life experienced by the working classes in the UK. This in turn helped the development of our modern way of life. Its impact cannot be understated. But, if we fast forward 150 years to our own century, we can see that the existing network is under a strain it was never designed to withstand.

What are some of the problems that affect cast iron pipework now?

In the city where the modern sewage system was first laid out, the existing water and sewage network is under strain. Leaks, corrosion and huge growth in population have overwhelmed the system. There is just not the capacity to meet the need. 

1. Leaks

By 2006, Thames Water had laid 2,300km of plastic pipework, replacing the original cast iron pipes, but much of the city is still served by the original pipework. Despite this, Thames Water remarked that about 900 Ml of water is lost through leaks every day in London. The improvements that they have made to date have only reduced the water lost through leaks by 36%. There have been 26,000 burst pipes in London between 2015 and 2019 alone. 

2. Corrosion

This is the most frequent cause of degradation to cast iron pipework. It can be caused by hydrogen sulfide, a gas often released from sewage, reacting with the iron the pipes are made from. The resulting corrosion can coat the inside of the pipework and damage the integrity of the asset over time. Degradation can compound the problem of leaks occurring throughout the network. 

3. Overpopulation

When the network was initially built, there were between 2.5 and 4 million people living in London. Now there are over 9 million. The system has not been developed in line with the population. There is simply not enough capacity within the system for the number of people living there. 

4. Flooding

The natural consequence of leaks, corrosion and overpopulation is flooding. The network is at 80% capacity even during dry spells, so when storms hit the capital much of the existing drainage and sewage system cannot cope.  

What’s the solution?

Much of the problems with the water and sewage system can only be solved by water and sewage companies building a larger network, and utilising modern materials that are less likely to fail over time. Many such projects are underway. But as with any development within a major city, such projects take time, and money and cause significant disruption. 

As non-destructive testing specialists, we work with other professionals to find creative solutions to many of these problems. This brings me back to the start of my story today, to the work we completed with WRc on a burst cast iron trunk main in South Wales. It was only through applying several techniques that our technicians were able to determine the quickest and best way to inspect the broken main. 

I am no Brazalgette! That guy was a genius. But, we can certainly take a leaf out of his book and determine to be as creative as we can when finding solutions for our clients. As an NDT company, we need to be ready to apply creative solutions to the challenges facing the Water Utility Sector so that we can deliver the assurance that our clients need that their equipment is operating effectively. And it is companies such as WRc, with their mandate to develop new technologies, that will solve our current infrastructure problems and continue the model of technological excellence that the Victorians instituted all those years ago. 

Responsive testing that delivers assurance that your equipment is safe.

Contact us for a quality testing service with a fast report turnaround. We can respond to any challenge.

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