Iron Age Slag – No Puns Please!

I’m Dawn McLaren and I’m a finds specialist at AOC Archaeology Group based at Loanhead, Scotland. On a day-to-day basis I’m principally involved in the post-excavation analysis of artefacts recovered as the result of developer-led excavations ranging from early prehistoric through to post-medieval in date. To give you an idea of the range of finds that I deal with, in the last couple of weeks I’ve been looking at coarse stone tools and querns from an Iron Age settlement, some pottery from a Bronze Age burial and post-medieval metal finds from an urban site in Edinburgh. It definitely keeps me on my toes!  

Today I’ve been examining some later prehistoric ironworking waste from a multi-phase site at Beechwood, Inverness and I’m really excited about what it is telling us about metalworking on the site.  The site, which was excavated by my colleague Rob Engl and others, revealed several Bronze Age/Iron Age timber roundhouses, palisades and enclosures together with evidence of Neolithic settlement.

Dawn identifying slag from Beechwood

Starting from the beginning, what is ironworking waste?  Basically, it is the non-iron component of ore that is separated out from the iron during smelting and smithing but there is inevitably other associated debris such as bits of ceramic hearth lining and vitrified stone which don’t necessarily need to be connected to metalworking. I’m terribly over simplifying, of course, but I hope this gives you an idea. Visually, this material doesn’t look like much, I admit! It often looks like rusty or glassy shapeless ugly lumps. But I’ve been trying for years to convince people that it’s really interesting and can tell us a lot about metalworking technology.

My first step is always to visually examine (macro and microscopically) the individual pieces looking at the colour, texture, shape and how melted and fused the material is. Another important part of the initial identification is to determine whether the material is magnetic. All of this information helps me to split the assemblage into broad categories: what is ironworking waste and what has been formed as the result of another pyrotechnic process, what is diagnostic of iron smelting and what might be bloom- or blacksmithing debris. Once I’ve identified the individual pieces, I record all the details (e.g. weight, quantity of pieces and measurements) into a spreadsheet so that I can feed in the contextual data later.

Small smithing hearth bottom from Beechwood

I’m pleased to say that the assemblage from Beechwood has a bit of everything!  It’s not a large assemblage but so far I’ve identified several smithing hearth bottoms and fragments of smelting waste so that I can say that both processes were taking place on or around the site.

Smelting slag from Beechwood

Now that my catalogue of the slag is complete I’ve started to look at where the pieces were recovered from. The excavations at Beechwood covered a very large area and I can see from my initial examination that the ironworking debris is focused in two quite disparate parts of the site. One area, which we’ll call A, includes a possible metalworking hearth or furnace associated with smelting slags and the other area, B, which is quite a distance away and must represent a separate focus of activity, has small residual amounts of both smelting and smithing debris. We’ve already had some of the pits and postholes from these areas radiocarbon dated and those associated with the ironworking waste have provided wonderful Iron Age dates.

Looks like my task for tomorrow is to see how the Beechwood evidence fits in to other Iron Age metalworking sites in the area!

For more information on our post-excavation services please check out our website:

What is in the Post?

One of the delights of specialist post-ex work is that you never know quite what the next delivery from the postman or courier will bring. Today’s delivery was of 15 crates of iron-working residue (almost quarter of a tonne!) from a medieval site in Ireland.

A quick look (its a bit like Christmas…!) shows a beautifully-preserved assemblage of slag and large fragments of tuyères (the ceramic ‘nozzle’ carrying the blast from the bellows into the blacksmith’s hearth).


A day in the life of an archaeologist in moscow, idaho

Friday- July 29,2011

Location: Moscow, Idaho

Hello fellow archaeologists and archy enthusiasts! My name is Molly Swords and I am a Historical Archaeologist/Cultural Resource Specialist II. I am working on the Sandpoint Idaho Archaeological Project, which has been a large, ongoing project for a couple of years. As a historical archaeologist whose focus is the American West, I feel very privileged to be part of this team of archaeologists!

The focus of the Sandpoint Archaeological Project was the old/original part of the railroad town of Sandpoint (circa 1880s to 1920s).  We excavated a known Chinese occupied area, saloons, brothel/cribs, a bordello, a dancehall, a commercial district, a blacksmith/machine shop for a lumber mill, a jail, a hotel, a privy, and a boarding house area (I hope that I did not forget an area). Most archaeologists love being in the field, but archaeology has a yin and yang about it: for all of the fieldwork that occurs in archaeology, there is also the lab and report writing that are just as important. A small assemblage of prehistoric artifacts were recovered, but the bulk of the artifacts recovered were historic. The excavation portion of the project has concluded, as has the cataloguing; currently, we are in the research/report writing phase of this project. Here is a glimpse of my Friday:

The day begins with carpooling with my roommates/friends/co-workers.  This project has us long term “temporarily” located in Moscow, Idaho, thus, my 4 roommates are all archaeologists who are involved on the project (one is a grad student working on her masters, another is finishing her undergrad degree, and 3 of us are full-time/round-the-clock archys).  In the Pacific Northwest, coffee is both god and goddess, so on our way to the lab, we swing by one of our favorite drive-thru coffee stands to get the caffeine needed to jump start our day.










The offices that we are currently working in/use are located at the University of Idaho in the Anthropology Department.  This is one thing that I love: being able to be around the college students and seeing them discover archaeology!  It is also lovely to have our offices right next to Priscilla Wegars’s office and upstairs from Mark Warner’s office!

Today my tasks included writing emails, answering questions, organizing research that was compiled earlier this week at the Bonner County Historical Society, filling out travel receipts (mileage and meal reimbursements) from my trip to the historical society, and conducting some research on children in the American west (google books and interlibrary loan rock!). I then caught up with my team of writers and helped with brainstorming some ideas for our report, taught a co-worker how to collect data for analyzing shoes, and checked in with the conservation efforts of a recovered barrel. I also poked my head into Dr. Priscilla Wegar’s office to say a quick hello, and checked in with Dr. Mark Warner while he’s on vacation (thanks Mark!).


As the day begins to wind down, the coworkers/roommates/friends (or “The Five” as Priscilla calls us) close down the office: make sure the doors are locked, lights are off, windows are closed, the coffee maker turned off, and we head home to welcome in the weekend!

B-B-Q, whiskey-cokes, and a beautiful Idaho summer night on the Palouse complete the day in the life of this archaeologist!

Project Start

The Friends of Chain Bridge Forge assemble at the Forge to mark the formal start of the project. The project was formally started by Councillor Christine Lawtown. The aims of the project are as follows:

  • Conservation

–      To create a living museum which tells the story of the Forge, the people, the Blacksmith craft and the relationship to the community that it served

–      Demonstrate the Blacksmith craft and to involve others

  • Participation

–      Develop the Friends of the Forge to manage and develop this asset

–      Fund Raising

  • Learning

–      Tell this story to schools and other interested parties


It’s key that we do this work now while the people of Spalding who used the forge are still available to contribute to its success.

Chain Bridge Forge – Overview

Chain Bridge Forge: Preserving a 19th Century Blacksmith

It is situated on the east bank of the River Welland about one mile from the town centre, only four metres away from the river itself. The building dates back to the early 1800’s and in 1826 it appeared in White’s Directory and it shows that the Blacksmith was a Francis South. It then appears to have been sold to Edward Fisher who was general town Blacksmith and from his 1850–60 day books it showed his trade also included the servicing the boats that used the port of Spalding. In 1898 the Dodd Family took ownership of the Forge and were recorded as Spalding’s last Harbour Master. Three generations of the Dodd family worked the forge. George Robert Dodd originally from Heckington in Lincolnshire had learnt his trade at Newmarket and presumably it had paid well enough for him to get married and purchase the forge for £280. The Forge had to adapt with the times and in the 1950’s Geoffrey Dodd business almost ended but he turned his hand to making carnival floats for the Spalding Flower parade and this continued for another 30years. In 1989 the building was sold to the local Council and work was done to preserve it structure but sadly was not developed as a museum.

Today we hope to fulfil this vision and The Friends of Chain Bridge Forge has been formed to conserve the artefacts, tell the story of this historic building and build an educational programme which will involve schools and the community. The building is approximately 12.3m long and 6.3m wide. It is subdivided internally into three spaces, the largest of which contains the forge and main work space. The floor is mainly of hard packed earth, with large pieces of stone and slate covering some areas. The building has remained largely unaltered and retains its original contents and is a treasure trove of artefacts and documents which illustrates this wonderful building past and the Blacksmiths that have worked it.

The Forge has recently been awarded £50,000 of Heritage Lottery Funding and therefore the project has commenced. If you would like to follow our progress or would like to contribute then please view our website