The Bonawe Iron Furnace, also called the Lorn Furnace, was an industrial complex in the middle of the eighteenth century with the aim of producing pig iron. Central to this complex was a furnace that was heated by charcoal. The complex was located at the site Bonawe in the District Lorn of the Argyll and Bute region of Scotland.
The industrial complex was built in 1753 by the small English firm of Richard Ford, called the Newland Company. The site was chosen because there was enough wood in the area for the production of charcoal. In addition, there was enough pressure water to drive a water wheel. As the company itself was established in Cumbria, the blast furnace was managed by a local representative of the firm. During the construction of the complex many materials were brought in from Cumbria. For the furnace to produce pig iron, it had to first be brought up to temperature, which took about one week. The oven was used almost continuously for nine months at a time. The complex employed as many as 600 people at the height of its operation. The majority of the staff were needed for the collection of the timber and the manufacture of the charcoal. The daily output could reach up to 2500 kilograms of pig iron and the annual production was about 700,000 kilograms. As the complex did not include a forge, finished iron products could not be manufactured, with the exception of simple objects such as cannonballs. The majority of the pig iron was taken to offices of the Newland Company in Cumbria to be shipped for further processing. As of 1750, the use of the blast furnace coke came in on a corridor. The first blast furnace in Scotland which made use of coke was built in 1759 near Falkirk. This new development in the production of iron in the complex made Bonawe less profitable. In the nineteenth century production fell sharply and the complex was closed in 1876.
The part of the complex that was needed for the production of the pig iron consisted of four separate buildings. Two of these buildings were used for the storage of charcoal, one for the storage of iron ore, and one for the housing of the actual melting furnace. In addition to these four buildings that had a central role, there were other buildings that were associated with the complex, such as buildings for the accommodation of workers, a home for the local representative of the Newland Company, and an aqueduct. There was also a pier for the supply of raw materials and shipping of finished product. There were two buildings for the storage of charcoal, but they also contained room for the storage of other products. The bark of felled trees was sold in turn to tanneries. The buildings were built on a slope, so the roof at the rear of the building was close to the ground. This made it easy to bring in new stocks to the rear side of the building. At the front, where the facade was much higher, it was simpler to remove the products from the building through the doors at ground level. The total storage capacity of these two buildings together was more than 2500 cubic meters.
This building was built on a slope to facilitate loading and unloading. In this building were hematite and other minerals, limestone and stored. All of these products were needed in the preparation of pig iron. This building was central to the function of the entire complex. The raw materials were placed in the oven from the southern wing of the building, which was designated as the charging house. The large door of this wing faced south. The stored commodities were kept in three other buildings. North of the smelter was a wing equipped with bellows, which continuously supplied air to the furnace. This wing was designated as the blowing house. On the eastern exterior wall of the house was a water wheel which kept the bellows in constant motion. The water for the wheel was raised from the river Awe via an aqueduct. On the west, side of the furnace was a third wing, called the casting house. In this latter wing, the molten iron was poured into pig iron rods. Also, the slag, a by-product of the production of pig iron, arrived at this side of the oven to the outside.
Your first reaction on finding a large iron furnace in this beautiful spot is to look at a map to work out where the iron ore came from. Your second is probably to look at the quarrying visible on the hillside at Bonawe on the far side of Loch Etive and add two and two. The discovery that the ore turned into iron at Bonawe actually came by sea from Furness, in what is now Cumbria, is a surprising one. Why would they bother? The answer revolves around the problem of transporting the fuel. Until the widespread use of coke in the late 1700s, iron furnaces depended for fuel on charcoal. And the large scale production of charcoal needed an awful lot of trees. Still worse, transporting the charcoal was a hugely wasteful business. The approach adopted by the English iron masters who ran the business was to take the iron to the source of the fuel. As early as 1610 they had set up a furnace near Gairloch in the far North West. Argyll contained plentiful woodland and Loch Etive became one of a number of centres to which ore was transported for smelting. Their first efforts in this immediate area were further up Loch Etive at Glen Kinglass. This only operated from 1722 to 1738. The lessons learned were used when setting up the Bonawe furnace in 1753. At its height, the Bonawe furnace was the centre of a significant settlement. The manager would have been supported by perhaps eight men producing the iron, plus up to a dozen more involved in arranging the delivery of the charcoal and maintenance of the site. They and their families, many from England, occupied the workers' houses still visible around the site. In addition there were up to 600 tree cutters and charcoal burners employed for at least part of the year across a huge area of north Argyll, coppicing wood and converting it into the fuel for the furnace. On average, a single day's production of iron required the the amount of charcoal that could be produced by cutting two acres of woodland. The centre of the process at Bonawe was the furnace itself. This was fed from the top with local charcoal, with iron ore from Furness, and with limestone from Lismore. Bellows driven by a waterwheel blasted air through the furnace, and the iron trickled out at the bottom. The iron produced at Bonawe was either cast into rough "pigs" for transport back to England and further processing, or it was cast into cannonballs. In 1781, Bonawe produced 42,000 cannonballs, varying in size from 3lb to 32lb.
An iron furnace was originally set up at Bonawe because of the slight cost advantage it offered over production in Lancashire. Production petered out in the middle of the 1800s, and eventually stopped altogether in 1876. Advances in technology, and especially widespread use of coke, meant that iron could be more cheaply produced in northern England, and in the central belt of Scotland. Bonawe's 120 year industrial revolution was over. Bonawe today is set on a beautifully grassy slope facing north towards Loch Etive. The higher parts of the slope are occupied by the large charcoal stores, plus the ore shed, still stained red from the ore. The ore shed also houses a fascinating series of displays charting the history of the site and information about the iron making process. Also on the site is a bark house. The oak bark, produced as a side product of the charcoal making, was valuable for the tanning industry. But the heart of the site today, as during its productive life, is the furnace itself. The upper parts of this show what worker's lives would have been like feeding the furnace, while the furnace itself can be seen from below via the hearth. Outside it is still possible to see the mill race from the reservoir to the south, together with the pit in which the water wheel sat until 1941.
The rough gravel car park has no accessible spaces marked. Nearest parking space is on flat ground 8m from the visitor centre, with a gate wide enough to allow wheelchair access. Visitors approach the site along a gravel path. The Visitor centre - The shop has step-free access. Bonawe is on a hill, with areas of shingle and cobbles on its slopes. The main circular route around the buildings is on gravel and grass surfaces and is about 250m long. The ground is uneven in places. The main exhibition room has 8 wooden stairs (with handrails) between its two levels. There is step-free access to both levels from outside. Unfortunately the nearest adapted toilet is 9.5 miles away at Tesco, Lochside. Assistance dogs are welcome.
Location : Bonawe Historic Iron Furnace, Taynuilt, Argyll, PA35 1JQ
Transport: Taynuilt (National Rail) then 15 minutes. Bus Routes : 415 stops near by.
Opening Times : April 1st to September 30th, daily 09.30 to 17:30
Tickets : Adults £4.50; Concessions £3.60; Children (5 - 15) £2.70
Tel : 01866 822432