Nemi ships (lead-sheathed hulls and bronze bearings)
Naves de recreo de Nemi (casco forrado de plomo y cojinetes de bronce)
- Date
- c. 40 (reinado de Calígula) · confidence medium
- Place
- Lake Nemi, Lazio, Italy
- Credited to
- Roman naval engineers working for Caligula
- Field
- Movement
⚠️ Disputed: the sources disagree.
What it is
Two ships about 70 m long launched on Lake Nemi, with lead-sheathed hulls, pipes, pumps and rotating platforms on bronze ball bearings. Recovered in 1928-1932, they show Roman engineering of a high order.
Their purpose (floating palaces, or ritual ships of Diana or Isis) is debated. They were lost in a fire in 1944, under disputed circumstances. Reading the bearings as true ball bearings is common but not unanimous.
What it led to
- bronze ball bearings in a turntable, long before the modern era
- studies of Roman shipbuilding and plumbing
- a source for models and replicas in the Nemi museum