Project...help?

I have a project to create in my metal work class and i just want to ask for opinion ideas etc... for my project folder which i need other people's view ....

here is the design task....

toon jumping is a very populair throughout the world. Design and make a working model of a fence for a toon jumping event, where the height of the fence can be adjusted electro-mechanically (limit/proximity switches should be incorporated as part of the control system)

any ideas for components and mechanisms and design ideas would be greatly appreciated because i am really stuck :P

Thank u
Alex (TheFan10's friend)