A Hellenistic-Roman bronze proembolion found off the coast of Libya: Test analysis of function, date, and metallurgy, with a digital reference archive
The Belgammel Ram is probably a Hellenistic-Roman proembolion, or upper ram, from a small military vessel or tesseraria. Dating of the ram itself is uncertain but appears to be in the last two centuries BC, or a bit later, on the basis of C14 and archaeological comparisons.
The Belgammel Ram was studied using the following techniques:
For surface examination:
- Surface non-contact digitising using a laser scanner
- Reflectance Transformation Imaging using polynomial texture mapping and hemi-spherical harmonics
- Digital photogrammetry with dense surface modelling
- Structured light optical scanning
- X-ray fluorescence analysis.
For the internal structure:
- The Ram was examined by X-radiography and 3-D X-ray tomography, and other techniques
Surface Analysis of the Belgammel Ram
A series of complementary techniques was employed in order to provide as rich an archive as possible in order to facilitate future research. The techniques used were:
- Laser scanning using a Konica Minolta 910 non-contact digitiser, producing 307,000 sample points per scan.
- Reflectance Transformation Imaging (RTI) to capture surface morphology.
- Digital Photogrammetry-Dense Surface Modelling, using a Nikon D300 with high resolution of 4000 x 3000 pixels and PhotoModeler Scanner.
- 3-D Optical White Light Scanner, using Breuckmann stereoScan system, controlled by Optocat R2 Software and Geomagic Studio 10 post-processing software
Microanalytic and Lead Isotope Characterisation
Samples were taken from the Ram by manual micro-drilling and approximately 50mg samples were taken at each sample site.
- J.J.R Adams
- A. Antoniadou (Queen’s University, Belfast)
- Gareth Beale
- P. Bennett (Canterbury Trust)
- I.W. Croudace (National Oceanography Centre, Southampton)
- Graeme Earl
- N.C. Flemming (National Oceanography Centre, Southampton)
- C.O. Hunt (Queen’s University Belfast)
- J. Moggeridge (Department of Non-Destructive Evaluation, AWE)
- K. Oliver
- A.J. Parker (University of Bristol)
- T. Whiteside (Department of Non-Destructive Evaluation, AWE)