Manual Part
This was a technology project that I submitted for my Junior Certificate Technology Examination. At the start of the year was given a choice between 6 broad project possibilities, I chose: “Design and make a working model of an electro-mechanically controlled drawbridge to allow river traffic to pass. Your solution must include limit switching to control the bridge at its fully raised and fully lowered position “
I started out by simply drawing out several ideas and trying to come up with an original solution that would meet all of the requirements. After some work, I decided that the project would be built in metal and that the design would feature the most compact solution to minimize different pieces to attach together and to maximize the project’s durability and strength.
Before deciding on a final design I conducted extensive research on existing solutions implemented on real bridges around the globe, I also investigated mechanism and circuits possibilities even though I already knew I wanted to use an Arduino to control the bridge and a traffic light.
For the circuit, I made 2 possible possibilities, one using a micro-controller and one just electronics. (sorry for the bad quality but I drew them by hand and had no electronic copy of my drawings)
Micro-controller Solution 
Basic circuit Solution
The actual building part of the project was incredibly fun. I enjoyed every single second that I spent building this. Although I encountered some difficulties, such as the big size of the piece limiting the tools and processes available to me, I still adored working on this project.
Code For Project
All the code that I wrote for this project is available and open-source on Github: https://github.com/NeriCarcasci/Bridge_control . If you have any suggestions in the code do not be contact me with your suggestions.