Thames Discovery Programme

Drains

Drains on the Thames Foreshore

What is it about drains that gets archaeologists so excited, and where can you examine them on the Thames Foreshore?

Log pipe on the Thames Foreshore

Without drains, city life would be nasty short and smelly. But they can tell us about technology, lifestyle and settlement patterns. Laboratory archaeologists can analyse samples of preserved sewage to provide evidence of diet. At TDP, we record where disused sewers and drains are emerging from the foreshore and how they were constructed.

The earliest drains yet discovered in the British Isles go back further than you might expect. At the stone-built Neolithic village of Skara Brae (3200 to 2500 BC) in the Orkney Islands a sewer runs under the houses, each of which have a drain opening into it. Later British prehistoric dwellings have not yet revealed such an advanced solution to the problem of waste disposal.

The Romans are rightly renowned for their water engineering, having constructed both aqueducts and sewers. The Cloaca Maxima (Latin for largest drain) still serves the area around the Forum in Rome. They seem to have preferred lead piping for water supply and brick or wood-lined drains for sewage, but hollowed-out elm logs have also been found dating to this period in Britain. In London, the Roman amphitheatre, now beneath the Guildhall gallery, has a well-preserved drain system including a silt separation chamber. When the Romans withdrew from Britain around 410AD and the Western empire collapsed around 476AD much of their engineering knowledge was lost across large swathes of Western Europe.

Throughout the early Middle Ages most drainage was provided by ditches and gullies. As the Middle Ages progressed, hardening the surface of these gullies with wood, brick or stone turned them into gutters providing drainage along the sides of larger roads and down the middle of narrower ones. These gutters were constantly flowing with water overflowing from springs and municipal water supplies like the great conduit. In times of heavy rain the gutters could overflow and cause flooding. by the 17th century these began to be covered over and increasingly became drains and sewers. Many of these were constructed from wood, either as box drains fabricated from planks, or as wooden pipes made from hollowed-out elm logs tapered at one end to insert into the next pipe and sealed with pitch or fat. These continued to trace the path of the earlier ditches and gullies which ran between different properties. As such they provide a valuable indication of property boundaries, often going back to the Middle Ages.

One reason drains on the foreshore are of interest is that they indicate where property boundaries are likely to have existed in the past. Many of them were used to direct surface runoff (e.g. rainfall) to the river to avoid it pooling in the streets or causing flooding. The would have begun as gutters and ditches being refined into gutters and eventually drain-pipes but remaining alongside the houses which once stood there.

The 17th, 18th and 19th centuries saw increased supply of water directly to homes and businesses in London through companies like the New River Company, rather than people being obliged to collect water from public fountains, standpipes or pumps. The widespread adoption of the water closet from the mid-nineteenth century onwards would have greatly increased the demand for household water supply and of sewage removal. Water was also in great demand for industry, particularly brewing, and also for firefighting and cleaning roads and ditches.

Water pump found on the foreshore near Gabriel’s Wharf

From 1848 to 1849 a major Cholera epidemic killed over 10,000 Londoners. Another outbreak occurred in Soho in 1854, despite the Metropolitan Commission of Sewers (created in 1848) having forbidden the use of cesspits before that time. Research by local physician John Snow demonstrated that the pathogen was carried in water contaminated by a nearby cesspit overturning the established belief that the cause of cholera was airborne.

1939 illustration showing how cholera could be spread (Vore Sygdome; Bind II, side 116: Public Domain)

In the summer of 1857, the smell from the Thames was bad enough that chalk lime, chloride of lime and carbolic acid were poured into the river to alleviate the stench. However, things grew even worse the following year and in July and August 1858 the so-called ‘Great Stink’ resulted in MPs refusing to sit in parliament. It was then acknowledged that some radical action needed to be taken. The Metropolitan Board of Works was instituted and Joseph Bazalgette was commissioned to design a new integrated sewage system for London. He was determined to create a system able to last and to cope with increases in demand. For this reason, he is recorded as doubling or tripling the recommended dimensions he was provided with, creating significantly wider sewers than deemed essential. Thus, more than a century and a half later much of London is still served by his network.

Bazalgette was not only a brilliant civil engineer, he understood the hydrology (the water flow) of the Thames. He canalised the river with new embankments creating a bottleneck creating a faster and stronger ebb tide which swept the sewage in the river out to sea in such a way that it no longer floated back into London on the incoming tide. He created three new embankments: The Albert and Chelsea Embankments, and the Victoria Embankment which not only contains part of Bazalgette’s sewer network, but also underground lines now used by the Circle and District Lines.

Joseph Bazalgette’s sewer network (By Philg88; Wikimedia Foundation)

An essential element of Bazalgette’s sewage system were the pumping stations at Chelsea, Deptford and Abbey Mills. They were not merely practical engineering but also built to be beautiful with elaborate decorative ironwork. This can be seen at Abbey Mills which is open to the public.

Bazalgette’s superbly engineered sewer system, with its large tunnels, has stood the test of time very well. However, in recent years problems with overflow of raw sewage in times of heavy rain have necessitated massive new overflow system: The Tideway Project. This magnificent feat of engineering has at its core a 25 km long tunnel running from Acton storm tanks in the West to the Beckton sewage treatment plant in the East. It is 7.2 m wide and runs from a depth of 30m in the East to 70m in the West giving a gentle downwards slope to aid flow of sewage. For much of its distance the tunnel runs directly underneath the River Thames.

Inside the Tideway tunnel (© Tideway)

h3. Identifying different drains on the foreshore

If you would like to see drainage features on the foreshore Southwark (from London Bridge to Gabriel’s wharf) and Putney are good areas to look.

Brick Gutters and Channels

Stone-lined gutters can be hard to date as the technology has been in use for centuries. Roman stone culverts have been excavated within the City of London. Brick-lined ones may be a little easier as brick styles change through time.

Brick gutter at Bankside

Wooden Box Drains

Box drains were used by the Romans and an example can be seen under the Guildhall Art Gallery forming part of the remains of London’s amphitheatre. Box sewers on the foreshore are more likely to date from the 16th to 18th century.

Box drain beside Blackfriars bridge (l) and Putney Bridge ® probably of 17th or 18th century date

Log Pipes

Although such pipes have been dated to the Roman period these are most likely to be of 17th/18th century date. Originally these would have been produced using hand powered large gimlet type tools but from the fifteenth century larger versions powered by water wheels or horses enabling larger and longer pipes to be produced more quickly. Usually the downstream end would be tapered to connect into the flared end of the next pipe. This joint would then be sealed using pitch or fat.

Hollow log drains on the Thames Foreshore under Cannon St. Rail bridge, probably 17th or 18th century

Ceramic pipes

Although ceramic drainage pipes have an ancient history going back to the 4th millennium BC, and the Romans used earthenware pipes, glazed stoneware pipes flared at one end to fit into one another (as shown below) became common from the 1880s onwards . Sherds of these are fairly frequent finds on the foreshore. A series of connected ceramic pipes may be seen at Putney.

Doulton pipe made at Lambeth and photographed at Surrey Docks Odessa Wharf

Metal pipes

The Romans used lead pipes from which we get the word plumbing, plumbum being Latin for lead. Roman pipes were formed from sheet metal, rolled around a former (usually wood) folded, heated, and beaten to seal it into a tube. Lead pipes were in use again by the 14th century. By the late 19th century the dangers of lead poisoning were becoming widely known and use of lead pipes dwindled. Use of cast iron began in the last quarter of the 18th century but cast iron, and subsequently steel, pipes became common in the later 19th century. Examples may be seen at Bankside associated not with drains but with hydraulic cranes and water inlets for the nearby power station. Other pipes (e.g. the metal ones in fig. 1) may have served as inlets for breweries to take in river water.

Metal Pipe at Greenwich