Hi
My solution as follows:
Drill two holes through the hanging rail close to either end of the rail. Buy a length of bungee cord and tie it tight so it goes up one side of the rail and back down the other (through each hole). If the hanging rail is quite long, then use a piece of string to pinch the cord(s) to the centre of the rail, dividing the hanging length into two. Normal hangers then are held onto the rail by the cord on either side.
This arrangement has just been 3600 miles around Spain and France without anything coming off once!
Cheers
Paul