Moving bridges: the drawbridge
Inventors (Intermediate), mission I6 Bridges & Structures, lesson 4 of 6.
Hook
Some bridges must move! How do you lift a bridge safely?
Fair test
Count crank turns to lift. Add a 50 g load. Does it still hold?
Bonus challenge
Time how fast you can open and close it for a passing “boat”.
The build
- 🏰 Castle Drawbridge: Wind the handle and the heavy bridge slowly rises — and stays up when you let go. (level 2 of 5, about 30 minutes, 15 steps)