Behind the cast iron windshaft you can see the horizontal oak brake beam. The wooden drum with rope on the left is connected with the brake rope, going down all the way. When you pull the rope, it turns the drum. On the right side of the drum on the other end of the iron bar, there is a chain connected to the brake beam. So when you pull the brake rope, the drum turns as is the iron bar. The chain winds around the metal bar and pulls up the brake beam. Whem completely lifted, the brake is loose. If you slowly loosen the brake rope, the beam lowers a bit, and a metal pen on the back is picked up by the metal sword in the middle between the drum and the chain. Then the brake beam is fixed and the mill can be operated. To brake again you just reverse the steps mentioned above. Seems complicated but is very easy and simple.