Bubba, I’m not sure of your electrical background, so forgive me for starting simple if you have covered all these bases: First off, is it truly a short, or is it actually an open? Many people will refer to a short, when actually they are talking about an interupption in power - an open circuit. I’m going to assume since you identified the problem as a short, that you are using a meter of some sort to determine that. Since you have unhooked the wiring from the track and you still are detecting a short, I would begin with a careful inspection of the track to make sure that there isn’t something metallic on the rails somewhere. It could be baling wire, tinfoil blown in by the wind, or a penny on a frog placed there by some prankster. If the inspection turns up nothing, then divide and conquer. Take rail joiners loose and separate the track into two or three sections, measuring each section to see which has the short. I doubt that the wet gravel has such a low resistance that it will cause a breaker to trip, or the ohm meter to measure less than 1 ohm. If you find that one section has the short, divide it into two or three sections and narrow it down again. It is a slow process, but you will eventually find the problem. One more thing - is this powered by a GFI and it is tripping out, there may be a ground fault issue in your power supply / throttle. Make sure you have voltage coming from the throttle itself. At any rate, see if these suggestions help, if not, reply with as many details as possible.
You don’t say where you are but your ballast can cause a short if it has a high metal content, especially iron. Do a bit of maintenance and brush it all away from the rails.
Hi the Steamer in that picture is a early Aristocraft Pacific track powered. My ballast is granite quarry dust. It was wet with all the snow that day. [:o)]