Recording tool marks at Buckler’s Hard

Learners on our MOOC ‘Shipwrecks and Submerged Worlds’ will already be familiar with our shipwrightery workshop at Buckler’s Hard in Hampshire (United Kingdom) through the steps on experimental archaeology and medieval seafaring in week 2. One of the main objectives of this workshop is for our students to use the tools of the trade and produce the tool marks they will be asked to interpret in their professional lives.

What occurred to us a couple of months ago was that there is no such thing as a ‘reference collection’ for tool-marks. When worked timber is found, a handful of expert are available with the expertise to interpret them. A reference collection of tool marks would allow students and professionals alike to compare the tool marks on the archaeological timbers they find with the ones recorded in the reference collection to make an educated assessment of which tool was used to produce those marks. The workshop at Buckler’s Hard provided an ideal opportunity to produce tool marks in a controlled environment with known tools and to start such a collection.

Reflectance Transformation Imaging (RTI) was used to record the markings. This is a technique that produces images in which light and shadow can be manipulated on a computer and is an excellent way to accentuate low surface topographies on flat surfaces. This allows us to pick up on the minutest details. The way it works is relatively straightforward. A camera is mounted on a tripod in front of the surface and a mobile flash is used to take images from different lighting-angles. All of the pictures are subsequently fed into the RTI-software which builds a manipulable image.

The two images above are snapshots of RTI-images. The first one shows adzing marks, while the second shows axe marks produced by a replica Viking Age hatchet. Tool marks like these, in the first place, inform us about the tools that were used to produce ship timbers and the craftsmanship involved. Furthermore, we hope it will be possible to compare tool marks produced by ancient shipwrights to those of carpenters. Did they use similar tools and did they handle them in similar ways? Were carpenters one and the same or did they move around in different communities of practice? And how does this develop over time? These are just some of the questions we hope to answer in the long-term.

The reference collection is currently under construction and will go live this summer on the website maritimearchaeology.com.

If you are interested in exploring RTI further, the necessary software if available for free through Cultural Heritage Imaging.