Chain Reaction device

This is not really pioneering, but is quite an ingenious piece of construction. The task I gave this patrol was to produce a chain reaction device (like Heath Robinson or Rube Goldberg) in one and a half hours. I knew things would be interesting when I heard them discussing how to use a cell phone to start the reaction off...

8 steps:

• cell phone vibrates, then falls
• broom tips over
• (slight pause in this video)traffic chevron falls
• retaining pole knocked away
• rugby ball rolls down slope
• into hat
• unties highwayman's hitch
• releases keys which slide down into Koen's hand

Direct link to the video here