CPSA

The 18th century water-powered ironworks at Agoreggi, in the Basque country, was reconstructed based on contemporary historical records and archaeological investigations. In 1994-1999 three campaigns of experiments were carried out with the aim of reproducing the scale and technology of the iron production. This paper is a fully illustrated description of the experiments and, in particular, of the practical problems of the air delivery system and the use of the copper tobera (tuyere). In 1999 six agoas (blooms) were made of varying quality and size, the largest being a 30kg ferritic agoa smelted from 140kg of ore, but this is only about half the scale of the 18th century production.
It subsequently transpired that the mouth of the tobera used for the experiments should have been 170% larger, thus allowing more air to be blown into the furnace, and the making of agoas closer to the 18th century size. See Crew 2013, 'Twenty five years of bloomery experiments...', pages [46-48], for an overview of the experiments and a brief discussion of the tobera problem.

This paper describes our 17th experiment (XP17), which was the first occasion on which a reasonable bloom was made. The smelt was of 7.5kg of moderately rich bog iron ore, in a low shaft furnace, resulting in a low carbon bloom of 1600g. Half the bloom was refined to a billet (642g), then to a flat bar (350g), part of which was forged to a knife. If the whole bloom had been refined, the total losses would have been more than half the original weight, resulting in three smithing hearth slags from each stage of the process. The data is used to make a preliminary calculation of the production from the sites at Bryn y Castell and Crawcwellt, where considerable numbers of smithing hearth bottoms were found.

For two periods of British history – the first part of the Roman occupation and the Tudor and early Stuart periods – the Weald of South East England was the most productive iron-producing region in the country. Looking across the tranquil Wealden countryside, it is hard to identify anything that hints at its industrial past. Yet 400 years ago, nearly 100 furnaces and forges roared and hammered there, the smoke from charcoal-making curling up from the surrounding woods and the roads bustling with wagons laden with ore and iron sows. Many British naval campaigns, including the Spanish Armada, the Wars against the Dutch, and The Seven Years’ War, relied on Wealden iron cannon; the pressures of conflict driving forward the development of iron-producing technology. For a time the economy of the whole area was dominated by the production of iron and its raw materials, providing employment, generating prosperity and shaping the landscape irrevocably. Drawing on a wealth of local evidence, this book explores the archaeology and history of an area whose iron industry was of international importance.

A selection of archaeometallurgical remains from the 3rd/4th century A.D., found in Aksum, Ethiopia, were analysed in order to determine the nature of the process by which they were produced, i.e. copper or iron smelting. Chemical and mineralogical analyses excluded a relationship to copper smelting; instead, all samples are consistent with a highly efficient iron smelting operation using the bloomery process and slag tapping furnaces. A lateritic iron ore containing at least 80 wt% FeO was smelted, resulting in an estimated one unit by weight of iron metal produced for every unit by weight of slag left behind, and little erosion of furnace wall material. The zoning of spinels, with chromium- and aluminium-rich inner parts and mixed hercynitic-ulvitic outer rims, reflects the evolution of the melt phase under strongly reducing conditions.

This paper discusses iron production in the Iron Age and Roman periods and the Middle Ages, the main expansion based on water power which brought the Weald to national significance in the 16th and 17th centuries, and the secondary working of iron by Surrey mills in the Thames basin into the early 19th century. Finally it suggests priorities for future research.

This bi-lingual interpretation board was erected at Dolgun Blast Furnace in celebration of its 300th Anniversary in 2019. This revised version has a new persepctive reconstruction drawing of the site using the latest evidence recovered during the 2019 excavations. The cut-away over the furnace pillar shows the evidence for the furnace lining, with the tuyere hole and the remarkable timp opening in the tapping arch, below which is a representation of the moisture chamber with a vent into the arch.
The drawing attempts to show all the key aspects of the charging, loading, blowing and operation of the furnace.
The board is at A1 size, but can be read easily in a 75% enlarged view.

Current research on a wide range of ironworking topics was summarised in 47 papers from 13 European countries, with other papers on Africa, India, Israel and Jordan. Topics include excavations, experiments, archeometallurgy, palaeoenvironmental studies, history and ethnography, with a date range from the early Iron Age through to the 18th century.

Current research on a wide range of ironworking topics were presented in 51 papers from 15 European countries, with other papers from Estonia and Africa. Topics include excavations, surveys, experiments and archaeometallurgy, with a date range from the Iron Age through to the Medieval period and with three papers on early blast furnaces.

A description and a critical appraisal of twenty-five years of ironworking experiments are presented. Initially the experiments were designed to answer specific questions raised by excavations at prehistoric sites in Snowdonia, where bog-ores with both high and low phosphorus were smelted in small diameter furnaces. Later excavations at a medieval site, where Mn-rich bog-ores were smelted on a large scale, raised new questions which were also examined. Other experiments used sideritic ironstones and hard-rock ores, from the east Midlands, Cumbria and Dean. A project at a reconstructed 18th century water powered bloomery in the Basque country is also described. Particular topics examined include the nature of the furnaces, the bellows and blowing rates; the ore, charcoal and clay types, quality and treatment; and the operating conditions, the products and the losses of material through the refining process. Models deriving from the experimental data and their application to the archaeological sites are presented. A number of general questions are highlighted and suggestions made for further work in experimental ironworking.

Excavation of the Anglo Saxon cemetery at Dover Buckland (5th-6th century AD) yielded ferrous metal objects. Five patternwelded swords, a weaving batten, a shield boss apex and four spearheads were examined metallographically. Three of the swords had hard steel edges. pp185-192

Over the past century, the powerful but mythical image of knights in shining armour, with bright polished swords to match, has dominated our view of what ironwork looked like: that of a polished greyish-white metal. This impression is gained not only from descriptions and illustrations in many books but is also obvious from even a casual walk around museum collections specializing in high status ironwork (such as the Royal Armouries in Leeds). But a close examination of much of this ironwork is likely to reveal that this was not its original appearance. Many poorly preserved patinated surfaces have been mistakenly removed by restorers and conservators wishing to improve the appearance of the objects in their care, not realizing they were altering the appearance by removing surviving traces of the original surface. However, it is possible to work out what much early iron or steelwork was originally intended to look like even if very little of the original surfaces survive. This can be done by the study of a combination of things: actual surviving traces, related decorative features (such as inlays), early descriptions, pictures, and even the use of inhomogeneous metal for certain objects or the making of composite ferrous artifacts. From this we can start to find out that much ironwork was actually intended to be either one or more colors, mostly in the range black (hence blacksmith) or dark grey to brown or blue, sometimes with one color intended to show up in contrast to another, or to a decorative feature such as an inlay. The probability that induced patination on iron surfaces was also intended to serve as a protective film is also indicated by some written sources. These issues need to be examined to promote a much better understanding of this little understood aspect of early ferrous metalwork, both to find out how and why it was intended to look originally and avoid bad decisions on how it should be cared for and displayed.

This chapter traces the growth of iron production from the pre-Roman period in the Weald of South-East England, describing the smelting technology of the time and quantifying production; it examines the role of the Classis Britannica and the possible existence of an imperial estate in the region.

This 32 page booklet gives a summary of 30 years of excavations at the prehistoric sites of Bryn y Castell and Crawcwellt, the medieval bloomery at Llwyn Du, and the 16th/18th century blast furnaces at Dol y Clochydd and Dolgun.
There are 15 figures, including site plans, artefacts, high resolution geophysical surveys and a high resolution pollen diagram. There are 8 pages of colour plates, with multiple images, including two pages of photographs from the linked program of experimental iron working.

Two large Roman iron bars, found in a 1920's excavation of a rectilinear smithing site, are described in detail for the first time. The bars are similar is size and weight to some of those in the St-Maries-de-la-Mer wrecks, found in the Rhone delta, and are argued to be one of the standardised forms of Roman trade iron, possibly imported from the Forest of Dean or South Wales. The European, British and Welsh archaeological and epigraphic evidence for Roman iron production and trade is discussed and illustrated.
This revised version has additional references with hyperlinks and new colour illustrations of the Sousse mosaic and the Augusta Raurica tombstone.