Hi all
Here's a baffling little problem for us to chew over. We have had Soberton out at the TRPS Show in Ferneham Hall yesterday and the fiddle yard was right at the back of the stage which was dimly lit. This allowed me to see the full extent of a problem we have known about for a couple of months, but has obviously been going on for quite a while.
The problem we are seeing is that when trains cross any pointwork (the throats of the fiddle yard are probably the best example) we are seeing sparking, almost as if we were looking at electrical units sparking over gaps in the third rail. The points are all Peco Streamline. The stock involved seems to be almost anything and everything; Bachmann, Hornby, the odd re-wheeled Lima, steam and diesel outline.
To begin with people were blaming old style metal tension lock couplers shorting from live chassis to frog, but in the dim light yesterday I was able to see the true nature and full extent of the problem (and examine the damage that is being done). This sparking seems to be happening towards the tips of the point blades and frankly a couple of the blades I looked at ought to be changed so this has obviously been going on for a long time. I am guessing that there is corresponding damage to the wheels as well but so far I have not been able to find any on my stock.
As far as I am aware the points are all insulfrog and the wiring of the points is totally "standard" but the evidence seems to suggest that somehow the point blades are actually at a different potential to the adjoining stock rails, and that the inner flange face of any slightly out of gauge wheels are managing to bridge the gap thus causing the sparks to fly (no, I didn't have a chance to get the meter out and check but I plan to the next time the layout is out). Also, we are not using any fancy electronics such as HF track cleaners.
Question: has anyone encountered similar problems and can they point me in the right direction to find a cause?
Thanks in advance.
Elliott