Computerised control demands reliable operation. The rolling stock has a major part to play!
- Locomotives need reliable pick-ups. Headlight flickering is a plausible way to check for pickup issues; the light should stay solidly lit all the time.
- All wheels need to be checked on a "back to back" gauge. Simply insert the gauge and adjust till the wheels are set correctly. it is surprising just how far out they can be.
- Bogies need to be able to turn freely. If they foul the body - for example because of "flash" on the body or bogie - then it may stick and derail at a corner.
- Couplings must not dip into the well between the rails. There are obstructions there on points etc.
- The rolling stock must not be so closely coupled that the buffers "bind" on tight radius bends. I have bends down around 11 inches (270mm) and a buffer-buffer distance of 3.5mm is an absolute minimum.