Bonawe Ironworks, Bonawe House

A series of measured surveys were undertaken by RCAHMS at Lorn Furnace, Bonawe, between 1962 and 1973. In each case, an original pencil drawing was redrawn in ink and the resulting illustration was published at a reduced scale. The final set of illustrations published in 1975 (RCAHMS 1975, figs 236-247) included:

Fig. 236: Site-plan

Fig. 237: General plan of furnace

Fig. 238: Upper plan of furnace

Fig. 239: Elevation and section of furnace

Fig. 240: Elevation of E charcoal shed

Fig. 241: Plan and section of furnace, ore-shed and charcoal-sheds

Fig. 242: Roof-details and section of E charcoal-shed

Fig. 243: Roof-details and section of W charcoal-sheds

Fig. 244: Ground and first floor plans of NE workers' dwellings

Fig. 245: Ground and first floor plans of SE workers' dwellings

Fig. 246: Elevation of SE worker's dwellings

Fig. 247: Ground and first floor plans of Bonawe House

BONAWE HOUSE. This mid-18th-century house was built as the residence of the manager of the Lorn Furnace Company, and is situated in wooded grounds about 300 m ESE of the main group of furnace buildings. The original house comprises three principal storeys with basement and garret, and is oblong on plan, measuring 13·9 m from E to W by 11·7 m transversely over walls varying from 0·8 m to 1·0 m in thickness(Fig. 247). The walls are of rubble masonry, harled and whitewashed, and the roof is covered with Westmorland slates. A prominent feature of the S elevation is the use of long thin slabs set horizontally with their edges projecting a short distance from the wall-face to form rough drip-stones above the window-openings. A two storeyed wing was built against the W gable-wall in the early years of the present century, and smaller additions were made against the S wall at the same period.

The principal (N) façade (plate 116d) is of five bays, having the entrance-doorway placed centrally at ground floor level. The ground-floor windows, however, have been replaced by large modern bay-windows. The windows of the second floor are not so tall as those of the first floor. The doorway (PI. 116E), which is reached by a short flight of steps, is framed within an imposing timber surround incorporating fluted pilasters and a triglyph-frieze which supports a Doric pediment. The S elevation, now much obscured by recent additions, has been of four bays, having a doorway in the second bay from the W at ground-floor level. At first-floor level the opening above this doorway is a Venetian window whose principal light contains wooden mullions which intersect in the window-head, while the W side-light is a mock opening, probably originally painted to imitate glazing bars. The E and W gable-walls terminate in long chimney-stacks which have been rebuilt during the present century.

The original internal arrangement remains substantially unaltered; there are, however, few original furnishings, all of the fireplaces having been replaced. Several of the doorways retain their original moulded architraves and six-panelled doors, and the openings leading into the principal rooms at ground- and first floor level are ornamented with panelling in the jambs and soffits. The entrance-doorway gives access to a hall flanked on the E by the drawing-room and on the W by the dining-room; the latter apartment has two elliptical headed recesses in the S and E walls. An elliptical headed timber arch springing from fluted pilasters divides the entrance-hall from the staircase-hall, where the rebuilt stair rises on the W, while a rounded projection on the E conceals a service-stair. A stone-flagged corridor containing the S door gives access to a large stone-flagged kitchen in the SE angle, from which the service-stair rises in the W wall, and to a smaller room, perhaps a study or office, in the SW angle. This room originally communicated directly with the staircase-hall, but the doorway is now obstructed by the lower part of the rebuilt stair, and has been blocked. A stone stair situated below the principal staircase leads down to the basement, which underlies the W part of the house; it comprises a wine-cellar and an apartment said to have been a dairy.

The disposition of rooms on the first floor is generally similar to that below. To the N of the stair-head there is a small lobby which gives access to both of the principal bedrooms, and between these rooms there is a closet; this was originally attached to the NE room, but is now entered by modern doorways from the NW room and also from the lobby. The apartment in the SW angle has been reduced in area by the insertion of a partition-wall to form a corridor giving access to the early 20th-century W wing. An original partition-wall forms a corridor in the W part of the SE division of the house; the service stair from the kitchen, which is lit by the splayed E side-light of the Venetian window, enters at the S end of the W wall of this corridor, and a similar stair, which provides the only means of access to the second floor, rises from a door in the same wall. The corridor and the SE room were originally lit by windows in the S wall, both of which have now been enlarged to form doors communicating with a modern extension.

The second floor has been extensively remodelled and contains no features of interest. The greater part of one original roof-truss is, however, visible in the garret. This is of a type commonly found in 18th-century pattern-books (eg Hoppus, The Gentleman’s and Builder’s Repository (4th ed, 1760), pl.76, no.2; Pain’s British Palladio (1786), pl.13), incorporating a shouldered king-post and two queen-posts with four diagonal struts. There are four purlins on each side, rebated into the principal rafters, and an obliquely-set ridge-piece. The slates are now carried on sarking-boards in the Scottish manner, but this is probably the result of re-roofing.

This is probably the house, 'built by a Mr. Knott of Coniston Water-head, a partner in the iron-foundry at Bunawe', the appearance of which failed to please Dorothy Wordsworth, when she visited the place in 1803 (Wordsworth, Tour, 145; Fell, Iron Industry, 273, 406).

RCAHMS 1975, visited September 1971.

Bonawe Ironworks, situated close to the s shore of Loch Etive by Taynuilt village, is one of the most extensive and best-preserved relics of the early iron industry in Britain. It was established in 1752-3 by Richard Ford and Company as an offshoot of their works in Furness, and leases of the site and wood rights were agreed with the above-mentioned Sir Duncan Campbell and the 3rd Earl of Breadalbane for a period of 110 years. Haematite ore was brought in by sea from Lancashire and Cumberland, and a rotational system of coppicing was developed for the manufacture of charcoal, charcoal-burning stances being found in many of the natural woodlands around this part of Argyll.9 After expiry of the original lease in 1863, a new agreement was negotiated with Alexander Kelly of Bonawe, but the furnace finally closed in 1874.

As well as the furnace and storage sheds, the company erected a manager's house, workers' dwellings, and numerous ancillary buildings, which included a school, a church, a jetty and a truck-store, creating in effect a self-contained industrial community.

At the heart of the complex are the manufactory buildings, all of which occupy bankside positions on the sloping site, thus utilising the changes in level to assist what was essentially a gravity-feed process. They are solidly built of lime-mortared random or coursed rubble masonry, chiefly of the local granite, but numerous features betray their Lake District origins.

The charcoal sheds, or coal-houses, are spacious, well ventilated barn-like structures covered with open timber roofs of tie-beam construction carried down over the side-ranges as catslides. Loading-doors were situated in the rear walls, and unloading-doors, at the lower ground-level, at the front, whence the charcoal was barrowed or carried to the charging-house. The iron-ore shed, lying along the contours just NE of the charcoal sheds, was designed to be filled and emptied in a similar manner once the shipments of iron-ore had been carted up the hill from the jetty.

The blast-furnace is typical of the kind used during the later charcoal phase of the industry in Britain. The furnace openings have cast-iron lintels inscribed Bunaw. F. 1753. Apart from considerations of stability, the size and shape of the furnace were determined by the need for an adequate insulating core to reduce heat-loss and by the shaft within, whose design had to ensure a good draught and likewise prevent the friable charcoal from being crushed by an overweight of iron-ore.

The blowing-house, casting-house, store and smithy enclosing the furnace on its Nand w sides are now ruinous, but the pitched roofs formerly covering these important ancillary structures can be traced by the socket-holes in the furnace walls for the roof-timbers-roofs, incidentally, which would have given an entirely different outward appearance to the furnace compared with today. Excavations have revealed the granite base-blocks of a blowing engine introduced at some time in the 19th century to replace the original leather bellows. Both types were powered through a camshaft worked by a low breast-shot water-wheel mounted in a pit and wheel-house along the E side. The floor of the casting-house was found to be divided by a stone kerb into a part-metalled area to the N and a bed of fine sand to the s.

The rear s wall is insulated from the earth bank and retaining wall by a narrow V-shaped cavity, which has a stone conduit running along its base and that of the casting-house-presumably for collecting seepage. At the upper level, the charging house and furnace were connected across the cavity by means of a joisted timber bridge (hence the alternative name bridgehouse), and by relieving arches on the side-wall. Directly beneath the bridge a long narrow chamber, carried on a joisted floor, was contrived within the cavity. Approached from the E by an external ramp, it probably served as a bothy for the furnace-keeper during the smelting operations, and possessed the amenity of a window and a fireplace set in the retaining wall, with horizontal flues issuing from the side-walls.

The principal manufactory buildings have been described approximately in the sequence in which they occur in the smelting process. Prior to this, the three ingredients-iron ore, charcoal and limestone-underwent certain pre-treatment. Thus, the ore was washed, roasted and crushed to reduce its sulphur content and other impurities. The limestone was also broken down, and adequate stocks of charcoal had to be prepared, customarily supplied to the warehouses in 1 ½ cwt. (76 kg) bags and stacked there in dozens. It was also normal practice to pre-heat or season the furnace about a week in advance; the hearth area had to be relined where necessary and the apertures forming the tuyere and the tap-hole then sealed.

At the commencement of the smelting-operations the raw materials were assembled in the charging-house and measured in the correct proportions—the ore and limestone by weight, and the charcoal by volume—after which they were carried over the bridge and fed into the furnace shaft to its full height. Once the furnace was put into blast, the campaign (to use the trade term) was continuous, with recharging taking place constantly over a period lasting from about late autumn until early summer. Aided by a limestone flux for removing non-metallic impurities, the charge was heated and reduced to molten metal as it moved down the structure towards the hearth, a temperature of up to 1200°C being achieved by an upward blast of air supplied from two sets of bellows blowing alternately. Periodically liquid iron was run off through the tap-hole into a principal furrow formed in a bed of sand, called the sow, and its lesser branches the pigs (hence the term pig-iron). The slag (impurities and unreduced ore), being lighter than the molten iron, was drawn off last over the slag-dam. It has been estimated that the furnace was capable of producing about two tons of pig-iron per day, which, owing to its high carbon content, was hard and brittle and normally required further refining. For this purpose, apart from some casting and forging on a small scale, it was the policy at Bonawe to ship the rough bars of pig back to commercial plants in England.

Water for the ironworks was led from the River Awe about 1 mile (1.6 km) to the east by means of an aqueduct, turning at right angles at the furnace to drive the water-wheel. Supplementary supplies were held in two reservoirs situated on the high ground near the manager's house and adjacent to the upper terrace of workers' dwellings.

RCAHMS 1986, visited 1960-75