Flintlock hand mortars were use for signaling, launching fireworks, and hurling grenades.
They would be operated by two men. One who would insert a lit grenade then duck. The first man ducking would signal to the second man, the shooter, the mortar was ready to fire.
In the event of the mortar not firing when a lit grenade was inserted the operator would throw the device and reel it in by an attached strap.
Ian’s Video: [5:48] https://youtu.be/kf9URQ7X0YA?si=
InRangeTV Video: [7:01] https://youtu.be/mAzdYxa6kHA?si=
I’ll crosspost it over there for them.