I've sometimes wondered is there a minimum 'criteria' (gauge, system length, speed etc) after which a railway comes under the scope of the rail authorities? For example RAIB have of course investigated accidents on the Romney, Hythe & Dymchurch, and I seem to recall they did an investigation into a derailment on a system at one of the safari parks a few years back. Is there a distinction between narrow gauge and 'miniature' which dictates this, for example?
I was recently at a steam gala on a superb little system at a country park, which operates with a fully functional signalling system including two signal boxes when at full capacity. There were numerous trains operating, passenger carrying as well as 'freight', all narrow gauge live steam, and trains were being held at red signals due to the density of traffic, a proper little miniature railway! Every passenger train carries a guard, who dispatches using flags. It's superbly run, but clearly the potential exists for incidents to occur. I wonder is such an operation able to be entirely self-policing?
