My loco travels half way round the track (the track is about 5m X 4m) then stops. I leave it for a minute, swithed off, then when I put the power on again it restarts. Then it stops. What is the reason for this repetitive power loss? I do not have a bus wire yet, but in any case I notice that the loco sometimes stops immediately adjacent to the track feed, so it cannot be the lack of a bus wire? I have checked the joints and fish plates. I am mystified