Achaeometrical Research in Hungary II., 1988

ANCIENT TECHNOLOGY - Gábor ILON: Celtic period fortifitations and an experiment to reconstruct the rampart - Gór (Vas county)

earth filling - if there had been any - was destroyed during the Roman Period with a pit, then the rest of the fill served as a basement for the Árpád Period timber fortification. Evidence of contemporary landscaping could be clearly observed during the course of excavations. Building material, its quantity, reconstruction (Fig. 6) The main building material of the rampart at Gór was earth dumped into a timber lace construction. No stone was used. The huge structure unearthed in sections D-l 1-11/E 1115 might have been a sand pit (Fig. 1). Its part within section E was unearthed by hand while the other one in section D was mechanically excavated due to lack of time. Its depth was 250 cm in the centre. According to our calculations

7

, approximately 230 m

3 earth may have been extracted from the archaeologically identifiable section of the pit. Complete measurements could not be taken since the pit's western part had been destroyed by the modern pit that is parallel to the dam. The average width of the rampart (as observed during the excavations) was 8 m, its height 2 m. The perimeter of the plateau (bordered by the 175 m contour line) it defended may be calculated as 585 m. Accepting these dimensions as valid, 9360 m earth must have been used in building the rampart. In this case, the parts defended only by a palisade can be disregarded. Should 80 % dry earth and 20 % clay have been used, these amounts would add up to 14,780 tons of earth. We also calculated that the Celtic cart from Inota could have carried, 1.5 m

3 when fully loaded. The transportation of 9360 m

3 with a single cart could have been executed in 6240 turns. Due to the great number of elements of uncertainty, it seems to make no sense to go any deeper into this problem. The quantity of the wood needed for the lace structure was calculated assuming a regular structure (Fig. 6). The measurements of a lace element are as follows: width 200 cm, length 150 cm. These data came from the averaged dimensions of the excavated features (see above in Fig. 4). The assumed average width (8 m) and height (2 m) of the rampart required the construction of 4 + 4 timber levels along horizontal planes, perpendicular to each other. The shifting of overlying timbers was prevented by posting upright timbers at the intersections (Figs. 4, 6). Considering a 585 m long plateau edge (Fig. 1) this would require 1346 m

3 wood. Calculating with the 0.8 t/m

3 average weights of the robur and Austrian oaks (Quercus roburf, we arrive at a total of 1310 t of wood. An attempt was made to estimate the type of wood needed as a raw material supply for this purpose. On the basis of the timber and log data recorded during the excavations, a hundred years old mixed forest with 23 m tall oak trees may have been sufficiently large for this purpose (BEKY 1989 Tab. 15). Namely, this is the minimum size range from which timbers, at least 10 m in length can be procured. From 1 ha, 150 m

3 oak can be felled. From this quantity, however, only 100 m

3 can be used as building material (the rest are branches and debris). These smaller pieces, however, may also have been utilised, for example in the support of earth i. e. preventing sliding) According to these estimates, the hypothesised 1346 m

3 wood could be procured from a forest extending over an area of 13-14 ha. With such a thinning of the forest, in the direct vicinity of the fortification - also reckoning with the utilisation trees for other purposes (building, industrial activities etc.) the possible "invaders" must have run into problems. 7 For help at calculations I would like to thank my wife Ilonné, Éva Márk. 8 We have not found a specialist for the identification of the logs rescued. 9

1 would like to thank László Keresztes, forest engineer, for the kind help. 232