The walls in the Unity Platform System are installed all along the platform to match the position of the train doors (for different model trains, two different systems have been proposed in the file; they are installed completely free from the train doors). The doors with roller bearings move on the seating sledge in the walls. All the doors are attached to one close circle rope, which moves over a pulley set. One drive group activates this rope. The drive group consists of one variable speed reversible motor, one brake and one drive sheave. There is no drive mechanism in/on each wall and door. The rope is pulled to the right or left by the drive sheave. All the doors open or close at the same time, being attached to the same rope. Besides, to bridge the gap between the platform edge and the train, three different 'Gap Devices' have been proposed in the file.