What goes into Surrey HER’s records: navigating further through Coxes Lock on the Wey Navigation

December 2, 20197:02 pmLeave a Comment

Are you curious about the information held in the Historic Environment Record (HER), the most comprehensive database of Surrey’s historic environment? The HER and the team are here to help you understand the whos, whats, whens, wheres, and whys of the county’s archaeology.

Last month’s post, ‘What the Surrey HER could do for you’, recounted a member of the public contacting the HER to report some previously unknown archaeology in their garden, which turned out to be late 18th-century grave footstones. This month we’ll continue to explore the ways we collect and evaluate the information that underpins the HER’s 23,000+ recorded archaeological monuments.

Knowledge of the historic environment is always evolving with the new research, studies, and surveys carried out across the county, and so the information held in the HER evolves with it. This involves either updating an existing record of known archaeology, or, creating a new record for previously unknown or unrecorded archaeology.

Surrey’s past isn’t locked down

Our record of Coxes Lock (Surrey HER Monument 3674), a 17th-century canal pound lock designed to control the water level and allow boats to move along the Wey Navigation, can help to demonstrate some of the ways we gather and evaluate the evidence that informs our archaeological records.

Coxes Lock looking south down the Wey Navigation (photograph copyright Sebastian Jones / SCC Historic Environment Planning)

The HER’s extensive library

The HER has an extensive library of published archaeological and historical research provides useful context when recording the archaeology of Coxes Lock. Alan R Wardle’s The Wey Navigations: An Historical Guide, published by the Surrey Industrial History Group in 2002, presents research on the history of the canal itself using primary sources held at the Surrey History Centre in Woking. In 1651 the Commonwealth Parliament passed an Act authorising the construction of the Wey Navigation to enable boats, largely transporting goods, to navigate between Guildford and the River Thames leading to London. By 1653 nearly ten miles of man-made channel was complete with locks, most likely including Coxes, and weirs. Waterways and canal building in Medieval England, edited by John Blair, tells us how the construction of the Wey Navigation coincided with a national movement to improve the navigability of England’s rivers in the 16th and 17 the centuries. These published pieces of research provide the historical explanation for why the archaeological remains of Coxes Lock came to exist.

Coxes Lock National Trust Sign
(photograph copyright Sebastian Jones / SCC Historic Environment Planning)

Cox’s marks the spot

We also refer to our collection of historical maps of Surrey to inform our understanding of archaeology. John Senex’s map of Surrey from 1729 labels the lock as “Cox’s Lock” instead of Coxes. It is possible the name derives from an associated person’s surname, Cox. Alternatively, it could take its name from the locality. Most of the sixteen other locks on the Wey Navigation are named for their location, such as “Thames Locks”, “Weybridge Locks” and “New Haw Locks”. Only two of the locks, “Triggs” and “Bowers”, have names that suggest an association with people. It is possible that Senex’s spelling, “Cox’s”, refers to an historic name associated with the land around the lock, which then changed over time to become commonly referred to as “Coxes”.

John Senex’s map of Surrey, 1729
(Public Record/Copy held by SCC Historic Environment Planning)

Investigate, document, report, repeat…

Archaeological investigations are carried out to acquire a better understanding of an archaeological site, or to identify new sites. After an investigation is carried out, usually by professional archaeology units or volunteer organisations and can involve excavating or surveying, a report is deposited with the HER and a record of this event and its archaeological findings, artefacts and features are added to the database.

But if it doesn’t hold water…

An unpublished document from 1995 and held in the HER suggested that the original 17th-century lock was constructed using masonry, rather than timber. This idea was not presented in a peer-reviewed publication and was not substantiated with sound evidence, so does not revise Coxes Lock’s archaeological record.

Archaeology under threat

Investigations are sometimes required by law under The National Planning Policy Framework, which is the government legislation designed to control the impact of development on the historic environment. Before planning permission is granted for a new development, an assessment must be made of the site’s archaeology, and with this knowledge a decision can be made about how to best mitigate the negative impact on of the development on the archaeology.

An 18th-century rebuild

In 1996 a desk-based archaeological assessment on the lock was carried out by CKC Archaeology. The report finds documentary evidence to suggest that the lock was originally built from timber and was turf-sided, as was the norm for the earliest types of pound locks built in England. Accounts of work revealed the locks were rebuilt with some 45,000 bricks and a new set of timber gates in 1770-1, which corresponds with the date stone marked with ‘1770’ on the north side of the lock.

North end of Coxes Lock
(photograph copyright Sebastian Jones / SCC Historic Environment Planning)

A chance to take a closer look

Repair works to Coxes and Weybridge Locks in 1997 required them to be partially drained, and so presented the opportunity for an archaeological recording of the features usually submerged below water carried out by CKC Archaeology. The bricks recorded in the lower portions and in the sluice gates were a type of brick consistent with a late 18th century or early 19th century date, so could possibly be material from the lock’s rebuild in 1770-71. The results of this archaeological investigation corresponds with previous documentary research, as well as making it apparent that none of the original 17th century building materials survive.

Coxes Lock repairs in 2009 (photograph copyright Tony Howe / SCC Historic Environment Planning)

Artefacts of industry

In 2012 the Surrey Archaeological Society reported the recovering blocks of copper smelting slag from within the lock. The slag appears to have been cast into rectangular moulds and used as bricks. But what could be the source of the bricks? In 1990 and 2009, during the draining of the canal upstream of the lock, a wall constructed from timber, brick and cast slag blocks was exposed. Blocks of dark-coloured, dense slag were also used in the construction of the millpond (HER Monument 15893) around 1782. The adjacent Coxes Lock Mill (HER Monument 3675) is also thought to have carried out metalworking between 1777 and 1831, and could possibly be the source of the slag blocks. Perhaps the bricks were accidentally lost during transportation from the mill to construct the millpond or canal wall upstream, or were possibly deemed surplus to requirement and discarded into it like a rubbish tip.

Coxes Lock (foreground) and Coxes Lock Mill (background)
(photograph copyright Sebastian Jones / SCC Historic Environment Planning)

The Modern Wey

The survival of late 18th-century brickwork remains discovered through archaeological investigation reveal Coxes Lock to be an important early example of water control devices in Surrey. By being reported to us, we could add this information to the HER and incorporate it into our understanding of Surrey’s historic environment.

More recent restorative work was carried out on the lock gates in 2017, which involved the removal of degrading building materials (that’s the archaeology) to prolong the functional life of the historic Wey Navigation’s Coxes Lock for years to come. However, owing to the HER and its record of Coxes Lock, this archaeological knowledge is also preserved and can be considered in future heritage assessments of the lock and surroundings.

Coxes Lock gates
(photograph copyright Sebastian Jones / SCC Historic Environment Planning)

The archaeological investigations carried out in Surrey, such as the recording of Coxes Lock, allows us to produce a more complete picture of the county’s historic environment. Through its tens of thousands of records, the Surrey Historic Environment Record provides a comprehensive account of this work and the knowledge uncovered in it. This knowledge can often help us to answer questions and to better explore Surrey’s past. Sometimes, however, it only produces more questions, as is the case with the unexplained copper bricks.

If you have questions about any element of Surrey’s historic environment that interests you, or would like to know more about what we do at the HER, please don’t hesitate to contact us at [email protected].


Blair, J. (ed.), (2007). Waterways and Canal-Building in Medieval England. Oxford: Oxford University Press.

Wardle, A.R., (2003). The Wey Navigations: An Historical Guide. Guildford: Surrey Industrial History Group.

Currie, C.K., (1996). A Historical and Archaeological Assessment of the Wey and Godalming Navigations and their Visual Envelopes: Volume I. CKC Archaeology

—————–(1997). Archaeological recording during repairs to Coxes and Weybridge Locks on the Wey Navigations, Surrey. CKC Archaeology.

Howe, T., Savage, R., and Savage, P., (2017). Downside Mill, Chobham: an evaluation with notes on observations from Coxes Lock Mill, Addlestone. Surrey Archaeological Collections, 100, 31-53.

Savage, R.W., (2009). Remains of elm timbers from Coxes Lock Mill Weir. Surrey Archaeological Society.

Seb Jones (HER Assistant)

Written by HER Assistant

2 thoughts on “What goes into Surrey HER’s records: navigating further through Coxes Lock on the Wey Navigation”

  1. Nigel Randall says:

    Interesting – especially the copper slag bricks. I wonder if there’s evidence of these ever being used in construction or were they just a convenient way to store the waste product?

    1. HER Assistant says:

      Hi Nigel, according to an article in the Surrey Archaeological Collections (volume 100, page 45) the canal walls upstream of the lock, as well as the adjacent millpond used slag bricks in their construction. Certainly, the canal construction could be a possible source of the finds in the lock. The same article also discusses how that at the end of the 18th century the Mill was reheating scrap iron to recycle it. At the Mill a slag block was discovered with an iron strip or flattened hoop embedded within it (which is now at Chertsey Museum). The mill’s metalworking would have been producing waste product, and the lock may have presented itself as a convenient dump.

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