#167: The story of Cumbrian iron

…in which we tour south Lakeland to tell the remarkable story of an industry that expanded from one-man bloomeries set deep in the woods to blast furnaces powering the industrial age.

In the company of industrial history enthusiast Mark Hatton we begin our journey at Glen Mary below Tarn Hows, where we are introduced to the three ingredients that allowed Furness monks to first produce iron: expansive woodlands, fast-flowing rivers and rich deposits of local hematite.

Noting clues of iron in the landscape – Red Screes, Red Pike, Red Tarn – we visit an oak-shaded glade that was once a charcoal-burners’ platform, where coppiced timber was piled high then baked to create the ‘rocket fuel’ charcoal required to generate temperatures of 1,000+ degrees centigrade.

Moving upstream, we come upon an ancient bloomery, where hematite from Orgrave (literally ‘ore pit’) was transported, by boat then pony, to ‘bloom’ in the charcoal hearth before being forged into weapons and farming tools to help Cumbria’s medieval farmers eke out a marginal living.

Heading south, we visit the site of a 17th century bloom-smithy in the heart of Coniston, learn about the laws introduced to ban timber extraction as Lakeland’s woods were fed to the furnaces, and the journey of Cumbrian entrepreneurs into Scotland as home-grown forests were denuded.

Ending our trip in Furnace Wood (the clue’s in the name) above Duddon Bridge, we explore a network of ancient holloways and moss-reclaimed cobbled trails, remnants of a thriving woodland industry feeding Britain’s largest surviving blast furnace, where a huge waterwheel powered bellows heating a next-generation hearth to fulfil the insatiable iron needs of the industrial age.

Taking a long view of a lost, and neglected, industry, we seek out a slate wall melted by fire before reflecting on the zenith, then decline, of Cumbria’s iron age, when Barrow alone produced more steel than anywhere else on earth.

• The Duddon Furnace (with parking alongside) is located at Grid Reference SD 197 883, immediately north-west of Duddon Bridge. More details can be found at https://lakedistrict.gov.uk/explore/things-to-do/historical-places/industrial-heritage-sites/

• The first site we visited was in Lane head Coppice beside Tom Gill below Tarn Hows (SD 3221, 9989). It is around a two minute walk uphill from Glen Mary car park (National Trust).

Mark’s linescape of the Duddon Furnace – from a photo taken in around 1890 after the works closed.

Our guest for the pod: Mark Hatton, standing on a historic charcoal-burner’s platform above Tom Gill, Glen Mary.

Slag waste – mainly silica – left in the landscape after the iron smelting process.

Holloway through Furnace Wood above Duddon Bridge – ancient road used by pack ponies and charcoal burners.

Cobbling – still in place after 150+ years.

Remnant of a charcoal burner’s hearth or chimney stack.

Mark on a raised charcoal pitstead in Furnace Wood: hiding in plain sight.

Duddon Furnace, active in the 18th century. The left-hand arch is the casting arch – from where liquid iron would flow into ‘pig’ moulds – and the opening on the right is the blowing arch, through which a pair of huge bellows would inject a constant blast of air into the heart of the furnace.

Close-up of the casting arch; its walls are some 20 feet thick. Ore was smelted in the inset hearth.

The vast charcoal storage house – the size of a church. The store room was kept full so the furnace could be kept in blast for periods of months on end.

Remarkable area of walling where a historic charcoal fire has melted the slate.

The top of the blast furnace, showing where the iron ore, charcoal and limestone were tipped into the hearth. Poisonous gases were vented through the chimney above.

Map showing pre-19th century bloomery sites around Coniston. It is taken from the paper ‘The Ancient Ironworks of Coniston Lake’, presented by antiquarian W. G. Collingwood to the Historic Society of Lancashire in 1901. We visited the Coniston Forge as the second location on the pod.