https://gunbai-militaryhistory.blogspot.com/2019/01/dokyu-japanese-crossbow.html
https://en.wikipedia.org/wiki/Ōyumi
Early Japanese siege weapon (bolt thrower and stone thrower versions.)
https://www.reddit.com/r/AskHistorians/comments/ncey0d/did_medieval_european_warships_ever_have_mounted/
Byzantines could potentially be one of the only 1000 AD civs with heavy/siege ships and siege bolt throwers, at least in Part 1 (more dark ages focused)