Mangonels in the Medieval Times fired huge spear called bolts, it was usually used to catch the towers alight.
We (my brother 'Halt and I) have built a mangonel from paddlepops.
It took 40 paddlepops to build.
We first built the base.
Then the sides, then the supports then the top and
finally the back as you can see.
We made a 'bolt' with paddlepops, two paddlepops thick. The 'bolt' flew fast and hard, it hit the wall on the other side of the room.