2. The Methodology

2.1 The site plans

2.1.1 Capturing and preparing the site plans

The first step for the digitisation of the plans was to scan all the necessary printed plans as TIFF image files. The next step was to redraw them digitally to prepare them for importation into ArcGIS. However, each plan, or set of plans, had problems that needed to be overcome before they could be redrawn digitally as a single comprehensive map of the site with Cartesian coordinates.

The most important problem concerned the differences in scales and alignments in the printed plans for each site. This applied particularly to the excavations of Vetera I, for which there are a number of published plans but no single comprehensive and so usable one. Hanel published a plan of the labelled buildings of the last fortress, at a scale of 1:5000 (Hanel 1995, pl. 169). Plans of the remains from the earlier fortresses are found in Lehner's earlier publications, also at a scale of 1:5000 (e.g. Lehner 1930, pl. II). Hanel published a separate overall plan of most of the 1629 excavation trenches at 1:2000 (Hanel 1995, plan 1). In addition, he published eleven more detailed plans showing the spatial relationships between particular buildings and excavation trenches in various parts of the fortress, at scales of 1:400 (Hanel 1995, plans 2-3, 5-12) and 1:350 (Hanel 1995, plan 4). These trench plans were published on sheets greater than A3 in size and needed to be scanned on a large-format scanner. Because of differences in scale and alignment, few of these plans could be easily registered alongside their neighbours. Therefore, to convert each plan to a common scale was quite achievable, but the unavoidable consequence was that gross inconsistencies of alignment and omissions of detail were revealed, each instance of which required considerable adjustment before digital redrawing could take place.

For the fort at Ellingen the process was simpler. One large A2 printed plan of the entire site, at a scale 1:250, provided the basis for the digitised map (Zanier 1992, plan 1). This printed plan includes the buildings and features within this fort, and their construction phases, which could be separated into 'layers' on the digital map.

For the fort at Oberstimm a number of the A4 printed plans, again at differing scales, needed to be compiled together to create the final digital map. These printed plans included overall site plans of the excavation areas at a scale of 1:1250 (Schönberger 1978, figs 2-3); overall plans of the building phases at a scale of 1:1000 (Schönberger 1978, figs 64-5, 67-8); details of particular excavation areas showing buildings and features at a scale of 1:200 (Schönberger 1978, figs 5-7, 13, 20, 22, 24-6, 30-1, 33, 42-4, 48-50, 54-6); and plans of individual buildings and their phases of construction, at a scale of 1:400 (Schönberger 1978, figs 23, 29, 32, 41, 46, 59).

Two main plans of the overall fort at Hesselbach were published at a scale of 1:500 (Baatz 1973, pls 2 and 4). These printed plans included all the buildings in the fort, with their construction phases, possible reconstructions and identifications.

The preparation for the digital map for Rottweil Forts I and II was more complex. It, again, required compiling information from a number of detailed plans at different scales, many of which were greater than A3 in size. Each plan was scanned, in sections, on an A4 scanner. The sections were then brought together and each plan re-drawn separately. The base plan showed the fortifications of the two forts, at a scale of 1:2000 (Franke 2003, plan 11). Summary plans of the excavation areas and reconstructions of the barracks buildings, also at a scale of 1:2000, provided the basic grid system on which the more detailed plans could be aligned (Franke 2003, figs 12-14). Details of each excavation area, and the features and phases excavated, were taken from plans at a scale of 1:200, with relevant grid coordinates (Franke 2003, figs 6, 20, 27-8, 30, 39-40, 45, 50, 52, 57, and 59, and plans 1-10). Reconstruction plans were also incorporated into the digital map (Franke 2003, figs 60 and 62).


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Last updated: Mon Jun 30 2008