Gunpowder mill from Old Mill, Surrey

Between February and August 2020, Cotswold Archaeology undertook an archaeological watching brief and excavation on an 18th–19th gunpowder mill located at Old Mill, Old Malden Lane, Worcester Park, Surrey, on behalf of Taylor Wimpey.

Powder Mill A
Powder Mill A

The gunpowder mill opened in the early 18th century and operated until the mid 19th century, when an explosion forced its closure. It was subsequently repurposed as a Victorian corn mill. The location of the mill beside the Hogsmill River was chosen due to the strength of the river’s flow, with the Hogsmill River being famous for the corn, paper, and gunpowder mills constructed along its length.

Maps that show the locations of the gunpowder mill’s individual buildings and canals correlate with our findings at the site, as do drawings of the mill buildings and machinery, which were produced in 1771 by John Smeaton, the ‘Father of English Civil Engineering’.

To date, we have found two groups of structures at the site: the mill’s buildings themselves, and a complex system of mill ponds, culverts, leats, and outflows, all designed to harness the power of the river to drive the machinery necessary for the production of gunpowder.

The westerly structure appears to have been heavily damaged in the 1854 explosion at the mill, while the eastern structure is substantially more intact. The latter includes blast walls, evidence of scars left by the water wheel that drove the machinery, and some of the machinery itself. There is also evidence for the modification of the mill to allow for the grinding of corn.

One of the millstones
One of the millstones

Some of the small finds discovered at the site include a hobnail shoe, which appears to have incorporated copper rather than iron hobnails in order to reduce the risk of sparks – a clear danger in a gunpowder mill.

Nigel Randall, Archaeological Officer with Surrey County Council’s Historic Environment Planning Team, said: “The work undertaken to date has been exemplary and the features revealed are certainly of regional and possibly national importance. We are ensuring that all the structures and features revealed are being carefully recorded.”

David Buchanan, Technical Manager at Taylor Wimpey South Thames, said: “Uncovering the mills and learning about the history behind them has been extraordinary and incredibly insightful. As the excavation is part of a planning condition, we have been working with Cotswold Archaeology, Surrey County Council and Barkemp Construction to ensure the structures are safely excavated. We have also taken all necessary precautions to secure the safety of our employees, appointed consultants and subcontractors.”

The following report appeared in The Sussex Advertiser of 21 August 1849.


This quiet village was thrown into a state of consternation, truly terrifying, about twelve o’clock on Tuesday night last, occasioned by the explosion of a gunpowder mill, in the vicinity of Worcester Park, leading into the Ewell Road, the property of Mr Frederick Taylor. The mill at the time was in full work, containing a great quantity of powder. Fortunately, the only individual who was employed had left a few minutes before the explosion or the consequences to him would, no doubt, have been fatal. The noise was heard for some miles off. All the woodwork, of which the mill was composed, was blown to atoms and scattered all round the place into the road. Happily, it occurred at night, or in all probability human life would have been sacrificed.

Ray Kennedy

Powder Mill B
Powder Mill B
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