Waterproofing Roman ships

[guy]

 

A recent study suggests how ships were possibly waterproofed in Ancient Rome.

A molecular study of the Ilovik–Paržine Roman shipwreck off the coast of Croatia shows that its hull was waterproofed and repeatedly repaired using pine‑tar pitch and a pine‑tar–beeswax mixture (zopissa), with pollen trapped in these coatings revealing 4–5 distinct recoating events carried out at different Adriatic and Mediterranean locations. It gives rare insight into ancient shipbuilding traditions and long‑distance maintenance practices.

Two distinct waterproofing materials were used:

-Pure pine tar (pitch) — the primary coating across most samples.
 

-Pine tar mixed with beeswax (zopissa) — a flexible, hot‑applied adhesive known from Greek shipbuilding.

This is the first molecular analysis to document this combination on this vessel.
 

Pitch naturally traps pollen, allowing researchers to identify vegetation signatures.  The pollen recovered points to a mosaic of Mediterranean and Adriatic environments—dense stands of holly oak and pine, broad stretches of coastal scrub rich in olive and hazel, and the mixed vegetation of river‑influenced valleys.

These signatures point to multiple geographic sources, implying the ship was repaired in different Adriatic regions during its working life.

 

https://eandt.theiet.org/2026/04/24/roman-shipwreck-repaired-unexpected-materials-molecular-analysis-reveals

Edited April 25 by guy