Ballister
This has all year round appeal. It can be used for snow balls in the winter and wet sponges in the summer!
Equipment
- 9 x 6ft (2 metre) spars
- 1 x 8ft (2.5 metre) spar
- 1 x 12ft (3.5 metre) light spar/stave
- 2 x 6ft (2 metre) light spar/stave
- 15 lashing lengths
- Sisal or light cord
- Polythene bags eg: bin liners
- Old frying pan
Method
Construct two similar A frames using 3 x 6ft (2 metre) spars with a sheer lashing at the top and a square lashing at either end of the cross bar.
Join the two A frames at low level with two further 6ft (2 metre) spars.
Lash the last 6ft spar between the A frames, half way up the struts and on the inside of the structure.
Pad the crutch of each A frame with polythene bags to act as a bearing then rest the 8ft (2.5m) spar on top. It may be necessary to tie these in place. (a) Tie a short length of sisal across the top of each A frame to keep the 8ft spar from jumping out. (b)
Using a square lashing, fix the 12ft light spar to the 8ft cross member. The long spar should be positioned so that when the 8ft spar rotates, the end of the 12ft spar will clear the bottom cross member but will connect with the upper one. (c)
Two 6ft staves are lashed between the outer ends of the pivot (8ft spar) and the 12ft spar to act as a brace.
The frying pan is fixed securely to the top end of the 12ft spar. The final two lashing lengths are fixed to the bottom of this spar, ensuring that they are clear of the upper cross member when pulled.
For energetic use it may be necessary to guy out each A frame and lash the feet to large pegs driven securely into the ground.
For use – load the missile into the frying pan and pull on the ropes. Everyone else should stand clear!
The two pulling ropes can be replaced with inner tubes.
To download the complete plan and design document please Click Here