thumb|A Song dynasty louchuan with a trebuchet, depicted in the Wujing Zongyao
thumb|A Song dynasty louchuan with a trebuchet, depicted in the Wujing Zongyao
Louchuan () were a type of Chinese naval vessels, primarily a floating fortress, which have seen use since the Han dynasty. Meant to be a central vessel in the fleet, the louchuan was equipped for boarding and attacking enemy vessels, as well as with siege weapons including traction trebuchets for ranged combat.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).