In Pliny the Elder Natural HistoryA Roman scholar described how the Empire used a unique organic mixture to keep boats waterproof. By following an atypical 2,200-year-old shipwreck, researchers confirmed that not only was this true, but that Roman shipbuilders continued to repair their ships during their voyages.
A Boundaries in materials A study published today explains how pollen trapped in a Roman shipwreck was studied Ilovik-Parjin 1revealed the composition and origin of waterproof coating materials. Because organic matter decomposes easily over time, it has been difficult for marine archaeologists to fully understand ancient shipbuilding techniques. To overcome these challenges, the team behind the study developed an interdisciplinary analysis that combined archaeology, chemistry and palynology (the study of pollen grains).
The team confirmed not only that Roman shipbuilders used sophisticated waterproofing techniques, but also how the ships would be continuously renewed with more coatings to keep them afloat for a long time.
“This approach allows us to investigate potential variations related to functional or technical differences or even to repair the stages of application of waterproofing materials,” study co-authors Armelle Charrie and Quentin Couillebault told Gizmodo in an email. The aim was to “generate more robust interpretations and expand the range of hypotheses”.
Revisiting the shipwreck
Ilovik-Paržine 1 was originally discovered in 2016 and has been explored ever since widely studied. However, these studies primarily looked at the ship’s structural design and age. During these projects, researchers observed a thick coating of organic glue on the exterior and interior of the hull, according to the study.
“Organic archaeomaterials are of increasing interest because they are rich in important and unique information,” said bioarchaeologists Charrié and Couillebault of the University of Strasbourg and the University of Aix-Marseille in France. “They provide information on many areas, such as clothing, funerals, food, domestic life, or production techniques of the population being studied.”
But these organic materials rarely survive. As such, the residual coating provided researchers with a rare, invaluable opportunity to study the ship’s coating, which Charrie had previously examined on other shipwrecks.
Pollen and in zop
Speaking to Gizmodo, the researchers emphasized that different disciplines play very specific roles in the study. Palynology, which looks for pollen grains trapped during the process of manufacturing or applying the coating, has pinpointed when and where the waterproofing repair took place. Chemical analysis confirmed the corresponding molecular fingerprint in zopA mixture of pine resin and beeswax described by Pliny the Elder.
As a result, the team uncovered a very complex shipbuilding process. For example, in zopthe inclusion of beeswax and tar improved the flexibility of the glue. It fell among the pollen in zop layers were traced to different environments, from dense oak, pine, olive or hazel forests to alder and ash, to areas closer to water. This complementary information allowed the team to paint a more complete picture of all the different places the ship had sailed before its demise.
Mariners’ record
Most importantly, these findings drew the team to broader cultural practices in the region. The samples had four to five coating phases applied at different times and locations. This allowed researchers to reconstruct a possible navigation route for the ship around the Adriatic and even pinpoint when and where it received repairs and recoating.
Moreover, the oldest archaeological use in zop Charrié and Couillebault told Gizmodo that it dates to the late 7th century BC, which is consistent with “archaic Greek tradition.” The researchers explained that this indicates extensive “circulation of technical knowledge and technological transfer phenomena” across the Mediterranean basin.
