The mechanism works with a simple gas damper (allways pushing). The mechanism allows to maintain the door closed in every moment but collapses in 2 points: opened and closed. Due to the gas damper, it's impossible for the wind to open the door but it's quite ease for the crew to do that. until you push to almost 85º opened angle, the door wants to close. when you push for more than 85º, the door wants to open (due to the gas damper). it is very easy to close the door because the damper.
This hisge is based in the mechanism of the hinge of the trunk of a car.
The full mechanism is inside the wall and the only things you can see are the brackets in top and bottom of the door.
The mechanism is designed to fulfill the regulations, to support a more than 100kg door. It's easy of maintenance and manufacturing. the design allows the use in marine environment.