With an average stone weight of somewhee in the vicintiy of 200lbs, the cycle rate on this puppy was one launch every 15 seconds.
One every 15 seconds.
Heavier stones were used, of course, up to 3000lbs it is believed.
That is a lot of pouundage.
The siege engine does a whole lot of work and can carry a big load. A real big load.
It was most recently seen being used in the Syrian civil war (I would post a picture but I do not believe it is appropriate).