A 2nd-century Roman barge, 17m of its original 28m, was unearthed in Lyon and painstakingly preserved through advanced techniques.
Roman barge found in Lyon
In 2003, archaeologists from Inrap discovered 16 boats on a construction site for an underground parking lot on the edge of the Saint-Georges district, on the right bank of the Saône in Lyon. Among them was a Roman barge from the 2nd century AD, originally measuring 28 meters.Preservation process of the barge
To preserve the Roman barge, it had to be dismantled into nearly 1,000 pieces. The wood was consolidated with polyethylene glycol (PEG) and then lyophilized in Grenoble, at Arc-Nucléart. This process involved freezing the wood and drying it under vacuum to prevent damage.Details of the 16 wrecks
The details of these 16 wrecks are included in a monograph published in 2010 in the journal Archaeonautica. The book, directed by Éric Rieth, includes five large Roman barges, a ferry or lighter, two medieval canoes, seven fishpond boats from the early 16th century, and a boat dated 1746.Excavation and research
The excavation was conducted by Inrap under the direction of Grégoire Ayala, with Marc Guyon for the study of Gallo-Roman vessels. The site thus recounts more than fifteen centuries of life on the river, from ancient trade to later uses. One of the fishpond canoes was restored and entrusted to the Gadagne Museum in Lyon.Restoration and relocation
The biggest piece was the Roman barge, named "Lyon Saint-Georges 4" (LSG 4). Out of the original 28 meters, the excavators only unearthed 17 meters of the hull. The barge spent a decade in a water area, in provisional conservation, before returning to solid ground on January 28, 2014. It was sent to Grenoble for restoration.Challenges of preservation
A wood that had remained eighteen centuries underwater cannot simply be dried in the sun. It would deform, crack, and collapse. The team installed the barge in a 200-square-meter workshop with controlled temperature and humidity. The dismantling involved removing 2,100 nails, as iron could cause damage through oxidation.Restoration techniques
The pieces were first cleaned of metallic compounds and then impregnated with PEG for a year. They were then lyophilized, frozen at -30 °C and dried under vacuum. For the most damaged parts, restorers used resin and gamma radiation. Arc-Nucléart, a laboratory affiliated with the CEA, is one of the few capable of such large-scale impregnation.Future display of the barge
Inrap and Arc-Nucléart announced the end of the treatment in September 2016. The barge is intended for the Gallo-Roman museum in Lyon-Fourvière, now called Lugdunum. The constraints are heavy, requiring the museum to move its current reserve to accommodate the boat.Uncertain timeline for display
After the restoration, the wreck was to be dismantled again and stored under controlled atmosphere. The timeline for public display has varied over the years, with no confirmation of a public display to date. Before visiting, it is better to inquire directly with the Lugdunum museum.New research agreement
Another agreement was signed on October 11, 2016, at the Fourvière Museum between Inrap and Lyon Parc Auto, for new research on the LSG 4 barge.
