Ca’ Foscari hosts Dr Pat Tanner, leading 3D maritime archaeology expert

Dr Pat Tanner is one of the world’s greatest experts in 3D maritime archaeology. He has joined Ca’ Foscari as a visiting scholar to collaborate with the Venice Centre for Digital and Public Humanities (VeDPH) at the Department of Humanities.

Dr Tanner, who obtained his PhD from the University of Southampton, has worked on some of the most important maritime archaeology projects on an international level — including the digital reconstruction of the ship remains of Sutton Hoo (the early 7th‐century Anglo‐Saxon burial ground which inspired the recent film The Dig), the Mary Rose (Henry VIII's Tudor warship, on display in Portsmouth), the Punic ship in Marsala (Sicily), the Yenikapi Byzantine shipwrecks (Turkey), the 15th-century Newport ship, the Bremen cog, and others.

Dr Tanner is a visiting scholar at Ca’ Foscari and he is currently working on the 3D reconstruction of a Roman ship from the 2nd century AD in Grado (Italy). The ship is eventually going to be reconstructed in the National Museum of Maritime Archaeology (Museo Nazionale di Archeologia Subacquea) in Grado. Dr Tanner is going to collaborate with professor Carlo Beltrame and Elisa Costa, a research grant holder who has been working on the project for a long time.

Dr Tanner is a well-known figure in the world of maritime archaeology. He combines his great skills in the field of shipwreck reconstruction with an equally great experience in the field of IT and technology. Pat Tanner began his career by building and repairing boats and ships, as well as sailing, for 25 years. An accident just over a decade ago forced him to change his career — he spent three or four years teaching boat building. His passion for sailing on old traditional boats led him to work towards preserving Irish heritage by documenting, measuring and recording data on boats. Eventually he met a naval archaeologist who asked him to collaborate on a reconstruction project. 

Following this collaboration, Pat Tanner obtained a PhD in Maritime Archaeology at Southampton University, using his experience of boatbuilding and sailing to aid the restoration or reconstruction of shipwrecks using naval architecture and computer software. After building a model, Dr Tanner conducts tests to verify whether the ship would float, taking into account the weight, the shape, the dimensions of the ship, as well as the cargo. The scientific results can either confirm the reconstruction or indicate that it is flawed. In addition to allowing researchers to establish whether the reconstruction is potentially accurate, these tests also enable researchers to learn more about the ship — where it was able to voyage to, what cargo it could carry, why it might have been shipwrecked.

“We had the opportunity to invite Pat Tanner to Ca’ Foscari,” explains Carlo Beltrame, “to work on the reconstruction of the Roman ship in Grado, which was started by Elisa Costa. Dr Costa has already digitised the hull and the cargo, based on the analyses I conducted a few years ago during some excavation campaigns which lasted quite a few years. This work is further complicated by the fact that we need to recover old documentation that is heterogeneous and partially incomplete — so a lot of data needs to be processed. Now we are working on reconstructing the entire ship, on the complete model, by comparing ancient iconography with the remains of shipwrecks from the same period and more recent wooden ships (which may have been photographed or even filmed), that can suggest ideas for the reconstruction of the parts that are missing.”

The remains of the Grado ship and its cargo of amphorae. Photo by Soprintendenza Archeologia, Belle Arti e Paesaggio Friuli-Venezia Giulia.

The comparison between the Roman ship in Grado with another famous ship, the Black Sea shipwreck, which was found in the Black Sea at a depth of 2,000 metres in exceptional conditions, is allowing Dr Tanner to match the remains of the Grado ship with its extraordinary 3D model. The shape of the hull of the Grado ship is being reconstructed, and the Black Sea ship is providing inspiration for the reconstruction of parts that have been lost, such as the side rudders, the beams and the mast. 

“Thanks to 3D digital reconstruction, we can make digital models and understand how the ship was used, and how it became a shipwreck,” says Dr Tanner. “We can understand the trade among different communities, how civilizations developed and changed. We can compare different ships, how they changed in size and dimensions for commerce. We believe that the Grado ship might have been 16.5 metres long and weighed between 6 and 8 tonnes. It was a sort of trabàccolo (an Adriatic Sea sailing coaster).

3D reconstruction of the Grado ship with amphorae

“In Roman times, people used different construction techniques. For example, the scarf they used to connect the two important timbers from the post to the keel was a very complex joint, super technical and strong — making it required many days. They understood that it locked itself together and was very strong and safe. This technique disappeared over time — today we use metal fastening, glue, and modern materials.”

“The Grado ship,” says Carlo Beltrame, “is peculiar because there is a hole in the planking, close to the keel and where a lead tube was inserted. We initially thought it might be a bilge pump — however, that didn’t make sense, because that system is used now for bilge pumps that are modern, electric devices. So we hypothesised that his tube was part of a suction pump that kept fish alive during the journey, and that the ship might have had tanks to transport fish that would be raised in pools by the Romans. This is something that ancient writers referred to, as they wrote about fish that were raised and transported. The water they were in needed to be changed, and this might explain the usefulness of this strange structure that served to pump water inside tanks. The Grado ship contained amphoras with fish-derived products, such as sauce and pieces of mackerel.”  

3D modelling in Maritime Archaeology is useful not only to conduct research, but also to set up exhibitions in museums, and to create virtual models that are so similar to the actual ship that they can show us how the ship would face the elements — thanks to simulations of wind in various regions of the world. These simulations can help us imagine how a ship could cope with strong waves, how its cargo might move, how its structure could give way, thereby creating a plausible scenario to reconstruct the sinking of the ship and its causes. This is all based on scientific data, engineering models, historical evidence — all of this data is combined to recreate ships that were lost centuries ago, and whose remains are a few wooden planks and amphorae scattered on the bottom of the sea.

Here is an example of Dr Tanner's work: reconstructions ranging from the Bremen cog to the "digital ship" with techniques similar to those used for video games 

The results of the research conducted by Pat Tanner and professor Beltrame’s research group — the 3D reconstruction and new hypotheses — will enrich the Museum in Grado and allow for the development of innovative museum education programmes. 

“All of this material,” says Carlo Beltrame, “could be made available to the Museum in Grado, which the Italian Ministry of Cultural Heritage finally seems to have decided to inaugurate. Nowadays, people expect museums to use digital resources to describe history — and archaeology is like storytelling. People will expect to see the reconstruction of a ship, to learn about its cargo, and about how it used to sail. Technology allows us to create all sorts of renderings, so the public can experience museums as much more than places where objects are stored and displayed. We can’t expect people to want to visit museums if museums don’t adapt to the times.”

Author: Federica Ferrarin / Translator: Joangela Ceccon