This is the eleventh in a series of posts exploring 3D modeling in Mediterranean and European archaeology. For more in this series click here. We hope these papers will start a discussion either in the comments of the blog or on Twitter using the #3DMedArch hashtag.
Guido Nockemann, Freelance Archaeologist, AMD Nockemann,
In the beginning of the 16th century up until the Thirty Years War, the city of Lemgo was turned into a Renaissance fortress with a rampart, trench and bastions – unfortunately it was never finished. The southern entrance to the city was a bastion bathed by the river Bega with an associated gate construction with rampart and outer bailey on the city side (fig. 1).
Figure 1: The Langenbrücker gate on a copperplate print of Elias and Henry van Lennep, about 1663
During archaeological excavations from 2009 to 2011 in preparation for constructions of the Langenbrücker Gate, remains of a Renaissance bastion were uncovered. They uncovered the massive counter bearings of the former bridge, wall remains of the outer bailey, torwange, curbstones of the gate, remains of the foundation of the gate tower of the bastion, wall fragments of the northern part of the bastion and parts of the side walls (fig. 2 and fig. 3).
Figure 2: Southern abutment of the bridge and wall remains of the bastion (picture: Guido Nockemann)
Figure 3: Northern abutment of the bridge (picture: Guido Nockemann)
To present the results of the excavation to the public in a better way a 3D reconstruction of the southwestern part of the town fortification of Lemgo was established. It is based on the archaeological finds of the excavation as well as on historic plans and records (fig. 4). The point of time presented is around 1646, the end of the Thirty Years War, because the majority of data comes from that period. The archaeological evidence, however, is problematic due to consistent constructions for over hundreds of years and the historic tradition is inconsistent. Historic drawings of the city are often idealized and do not necessary correspond to reality. Different illustrators at different points in time drew, to some extend, very different views of the city e.g. in roofing, variation and size of towers. Information from historic records and city maps were taken into consideration in establishing the model.
Figure 4: Detail of a cityscape of the city of Lemgo south, 1 Half of the 18th century
A scale floor plan was used as a base for the 3D model considering every data accessible. If there was more than one possibility to solve a problem of detailing, the most likely one was taken. Historic photographs of parts of the town fortification, still existing in the 19th century, were a huge help.
Overlapping old city maps with archaeological finds showed anomalies which can be explained by the inaccurate measurement methods of that time. If there were not any archaeological evidence for walls or buildings, their position had to be interpolated. While reconstructing the structures above ground, data from records and from drawings of the city could be used. As there are no hints to the materials used for the finishing of the fortification and buildings, no photorealistic textures were used in the model. With a button, the actual archaeological finds can be made visible in the 3D model (figs. 5 and 6).
Figure 5: 3D reconstruction of the bastion and gate system at the Langenbrücker gate (graphic: Morris Viaden – Kleinkino / Medienproduktion)
Figure 6: Detail of the 3D reconstruction (graphic: Morris Viaden – Kleinkino / Medienproduktion)
An introductory text is essential for the visitors to explain the basis for the reconstruction was established. The main problem with that is, to a scientist, a 3D model is just one way of interpreting finds, but the general public will take that model for “scientific evidence and truth”. It should be stressed in the description, that the model is just one possible appearance, even if it is a very likely one, of the fortification of the city of Lemgo.
• Guido Nockemann (in press): Die 3D-Rekonstruktion der renaissancezeitlichen Festungsanlage am Langenbrücker Tor in Lemgo, in: Archäologie in Westfalen-Lippe
• Guido Nockemann (2012): Lemgo – Langenbrücker Tor; Ergebnisse der archäologischen Untersuchungen, Kampagnen 2010 / 2011 (Online-Presentation: http://www.lemgo.net/fileadmin/image/redakteure/planungsamt/Denkmalpflege/Ausgrabung_Langenbruecker-Tor_2012.pdf)
• Link to the 3D-Rekonstruktion: http://www.lemgo.net/fileadmin/image/redakteure/planungsamt/flash/lemgo3d.html