The 13th-century Morgan Bible has some of the best Medieval illustrations for trebuchets, the missile-launchers that shot artillery using a beam that would cast stones or other things (such as human heads during the First Crusade at Nicaea) from an attached sling. There were two sorts of trebuchets — the ones that used hand-pulling to create the tension that would release a beam (a “traction trebuchet”) and the ones that relied on an enormous weight to create the tension (“counter-weight trebuchets”).
The one you see here is the former sort, and these were not as able to launch heavy artillery. They could throw smaller stones and whatnot, but were unlikely to have damaged castle walls or towers. These were the only sort until the end of the 12th century.
In fact, mining under castle walls was really vastly better than any sort of trebuchets for weakening stone structures. Probably the trebuchets were mainly used for attacking archers and other opponents on the castle walls and towers.
Sources: Errata, Michael S Fulton, Leiden and Boston, 2018, by Michael Prestwich in _War and History _ 2019 vol 26 (3) 430-444, See review of _Artillery in the Era of Crusades. Siege Warfare and the Development of Trebuchet Technology_ History of Warfare, Michael S. zFukto
