Publication Account

Date 1985

Event ID 1018726

Category Descriptive Accounts

Type Publication Account

Permalink http://canmore.org.uk/event/1018726

RCAHMS: Exploring Scotland's Heritage - Argyll and the Western Isles, 1985

At a time when transport costs are perhaps one of the most contentious issues in the Highlands it is ironic that in the middle of the 18th century it was more economical to ship haematite ore from Cumbria to Loch Etive side for smelting and then to transport the iron back to the industrial centres around the Irish Sea, than it was to transport the enormous quantities of charcoal necessary to the Lake District The key was the cheapness and availability of timber for charcoal and a visit to the furnace at Bonawe should be coupled with a walk through the National Nature Reserve at Glen Nant to the south, where the types of timber and the platforms on which the charcoal was produced can still be seen.

The furnace complex embodies a building style quite unlike the architecture of the west of Scotland, betraying the Lake District origins of the company that established it in 1753. The centre of operations was the furnace itself but to appreciate the flow of operations the tour should begin on the uppermost terrace where the iron-ore shed and charcoal sheds are situated. The charcoal sheds are built into the natural slope to allow loading from a higher level behind and unloading from a lower level at the front where there is access to the furnace. The sheds are high and airy (to keep the charcoal dry) with impressive timber and slate roofs. The iron-ore shed is of two periods of construction: the three storage bays to the south-east belong to the earlier period, and the extension to the north-east is rather later. Again the ore was unloaded from the track at the rear of the shed and then barrowed from the front doors to the furnace itself.

The furnace is situated in such a way as to allow the constituents of the smelting process to be inserted into the loading-mouth from one level, while the water-wheel and lade, which powered the bellows at the base of the furnace-stack were on a lower terrace. The charcoal burning with the aid of the bellows (or latterly a blowing-engine) at the base of the stack, was covered with iron ore and limestone tipped in from the top; the heat changed the iron ore into molten iron, while the limestone flux above absorbed impurities and could be run off as molten slag. Both metal and slag were run off through the western of the great openings at the base of the furnace into a casting house where the metal was cast into pig-iron and the slag removed to form huge heaps (in the area now occupied by the car park). The two openings at the base of the furnace stack are lintelled partly in sandstone and partly by cast-iron beams, three of which have the inscription 'BUNAW. F. [Bonawe Furnace] 1753'; it seems likely that the lintels were cast in the Lake District in readiness for the building of the furnace, and the sandstone lintels were probably also brought from Cumbria in order to ensure the smooth construction of this crucial building.

To the north of the main complex is the L-shaped block that formed the workers' dwellings, and to the east is a further row of workers' dwellings and Bonawe House, built in the later 18th century as the residence of the company's local managec but none of these buildings is in the care of the Secretary of State for Scotland, and there is no public access.

Charcoal-burning stances are a little-visited class of monument found on many of the formerly wooded slopes of Argyll. The platformsl measuring about 8m in diameter, were partly dug back into the hill-side and partly built up on the down slope with the material thus quarried. On this level base logs were carefully stacked round a central stake and the pile was covered with earth; the stake was then removed and the pile set alight. The transformation of wood to charcoal took up to ten days. There are good charcoal-burning stances in Glen Nant (parking at NN 019273), and spectacular though less accessible platforms are to be found at the head of Glen Etive, above the west shore of Loch Etivei these have been cut back into the slope with the down-hill side revetted by large boulders. There are about twenty platforms on this now bare hill-side, a telling reminder that the slopes were once heavily wooded (NN 1044).

Another furnace went into production at Furnace on Loch Fyne side (NN 025000) by agreement between the Duke of Argyll and a Lake District company; the furnace stack can still be viewed from the outside. One of the lintels above the bellows opening is cast, like those at Bonawe, with the name, or in this case initials, of the operating company and the date: 'GF 1755' (Goatfield Furnace).

Information from ‘Exploring Scotland’s Heritage: Argyll and the Western Isles’, (1985).