Fresh from Fotheringhay

We have the results of the survey at Fotheringhay Castle. You can find out more about what we found in Steve Parry’s excellent blogpost, complete with the earliest depiction of the castle.

The castle is most famous as the place where Mary Queen of Scots was tried and executed. It was thoroughly dismantled in the first half of the 17th century, leaving the motte intact but little else above ground. Thanks to work by the Museum of London Archaeology and funded by the Castle Studies Trust, we now have a better idea of how the castle was arranged.

Pioneering geophysical techniques

Some of the Castle Studies Trust’s projects have made innovative use of cutting edge technology. Nick Tarr explains how a new survey technique was used this year at Pembroke Castle.

Geophysical Survey Technologies (GST) was formed to improve survey equipment for archaeologists to use in all environments including equipment suitable for use in woodlands. The equipment, ideally, should be within the financial reach of amateur groups.

The prototype survey frame resulted from research into voltage surveys (commonly called resistance surveys) where geology or other conditions are unfavourable for conventional methodology. The frame uses a commercially available data logger and power supply but has all four electrodes on a compact mobile frame which is collapsible to fit in boot of a car.

Photo ©Nick Tarr
The prototype frame in use. Photo ©Nick Tarr.

The version used at Pembroke Castle was aimed at keeping the energy from the power supply within the archaeological layers so maximising any opportunity of detecting any archaeology present. A comparison with the conventional twin array in both parallel and zig-zag walking modes was made over a single grid which contained part of a building and a track. The existing twin array frame gave no clear signal for the building, the track was the only major feature seen.

The metal prototype frame. © Nick Tarr.
The metal prototype frame. © Nick Tarr.

The prototype frame gave much better results. A further test across a monastic site in west Wales has also shown improved results over the conventional twin array methodology. Development work continues.