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Ballistic experiments on glass replicas of 300,000 year-old, stone-age Levallois arrowheads for archeology


In cooperation with the Römisch-Germanisches Zentralmuseum (RGZM – Romano-Germanic Central Museum) in Neuwied/Germany, a procedure to reproduce ballistic experiments with stone-age spearheads was developed within the scope of a DFG project. As the original artefacts from the Stone Age differed individually from each other and as a possible destruction of the spearheads had to be avoided, identical glass replica were manufactured and used as reproducible test objects. The spearheads were fixed onto a short shaft, accelerated up to defined speeds by means of a pneumatic acceleration facility, and directed towards a simulated target. With these experiments, a systematic connection could be established between the fracture traces found on the arrowheads and the ballistic parameters and/or the hunting behaviour.


The required test set-up was developed and made available by the Working Group "Dynamic Pressure Measurement" of PTB. This set-up allowed influencing factors such as the velocity, the kinetic energy and the penetration angle to be investigated systematically and reproducibly for the first time. By comparing the fracture edges of the pre-historic spearheads with those of the reproduced ones, it was possible to draw conclusions as to whether they had been used as a throwing weapon or as a thrust weapon. Figure 1 shows the test set-up.

Figure 1: Pneumatic gun for firing the arrows, speed-measuring photoelectric barrier, and adjustable target

The target was designed in such a way that it simulates an animal body as realistically as possible (but also reproducibly) with the coat, rind, muscle tissue and bones. The coat layer consisted of leather rags, followed by approx. 3 cm of ballistic gelatine, a PU artificial bone plate of 6 mm thickness and another 8 cm of gelatine. Frequently, the traces which were produced on the glass replica by this simulated animal body actually corresponded to those found on the original spearheads. First results have shown that realistic hunting traces can be reproduced in the lab under controlled conditions. The analysis of the chippings of the arrowheads (see Fig. 2) also extended to the search for so-called "Wallner lines" – microscopic fractures that spread over a rigid surface. With the aid of these Wallner lines, it seems possible to determine the speed at which a surface has been cracked and, thus, to deduce the impact velocity.

Figure 2: Reproduced and original arrowhead, characteristic types of fractures encountered on glass replica which were compared with original firestone artefactsvelocity.

In previous publications of the archaeological community, it has already been suggested that certain chippings on spearheads can be attributed to concrete velocities. They indicate whether the weapon was thrust or thrown rather slowly but powerfully, or whether it was catapulted with high speed using auxialiary means. These hypotheses had, so far, however, not been convincingly proven from a scientific viewpoint. The real flying velocities of the spears were determined in preliminary tests and verified by means of literature.
Based on the images of various broken glass and firestone arrowheads which were provided by the RGZM, the chippings of both the replica and the originals were shown concretely and compared by means of the "dorsal" (rear side) and "ventral" (front side) surfaces of the artefacts. A great advantage of the experiments carried out resides in the fact that the history of the projectile (flying velocity, impact energy, angle of impact) was exactly known.




Holger Schönekeß, Dept. 1.3, WG 1.33, e-mail: Opens window for sending emailholger.schoenekess(at)ptb.de
Radu Iovita, Research Field "Palaeolithic" of the Römisch-Germanisches Zentralmuseum in Neuwied/Germany, e-mail:Opens window for sending email iovita(at)rgzm.de