Duddon furnace

Duddon furnace is one of the best-preserved charcoal-fuelled blast furnaces in England, standing on the west bank of the River Duddon in the Lake District county of Cumbria. It lies near Broughton-in-Furness, in the parish of Millom Without, an area that belonged to the historic county of Cumberland. Today it is a protected industrial monument, listed at Grade II*, and a rare chance to see how iron was made before coal and coke took over.

What is Duddon furnace?

It is a blast furnace built to smelt iron ore using charcoal as fuel. This was the standard method in Britain for centuries, until coke-fired furnaces made charcoal ironmaking uneconomic. Very few charcoal furnaces survive in anything like complete form, which is why this site matters well beyond the valley.

When was it built and who ran it?

The furnace was founded in 1736 as a joint venture between two ironmaking concerns of the Furness region, the Cunsey company and the Backbarrow company. In 1741 the Backbarrow company sold its share to the Cunsey company, which then held the works. The location was chosen for practical reasons: woodland nearby for charcoal, running water for power, and access to the estuary for shipping.

What can you see on site?

The complex was laid out as a working industrial unit, and its main elements are still recognisable:

• stores for charcoal and for iron ore,
• a wheelhouse, where a waterwheel drove the machinery,
• the furnace itself,
• a blowing house, which supplied the air blast,
• a casting house, where molten iron was run into pig iron,
• an office and a slag heap.

Apart from one extra charcoal store added later, the buildings have changed very little since the furnace was first built. That makes it easy to follow the production sequence from raw materials to finished pig iron simply by walking around the site.

Where did the iron go?

The pig iron produced here was shipped out from the Duddon Estuary. Vessels carried it to ports such as Bristol and Chepstow, where it served the shipbuilding trade and other industries.

Has it been studied?

Archaeologists investigated the site in the 1980s. Only interim reports from that work have been published, so some details of the furnace's operation are still not fully documented.

Practical tips for visitors

• The furnace sits in a quiet, wooded part of the southern Lake District, close to the Duddon valley, so it combines well with a walk along the river.
• Wear sturdy footwear, as paths in the area can be muddy.
• Respect the monument: do not climb on the walls, which are old and fragile.
• Check locally for current access arrangements before setting out.

Frequently asked questions

Is Duddon furnace still in use? No. It is a preserved historic structure, not a working furnace.

What fuel did it use? Charcoal, made from wood, rather than coal or coke.

Is it the same as Furnace ironworks in Scotland? No. The Scottish Furnace ironworks in Argyll is a separate site, founded later by a company from Cumbria.

Why is it protected? Because it is a rare and largely unaltered example of an early industrial charcoal blast furnace, hence its Grade II* listing.