Hi Folks,
It is now below zero in the mornings. While I wait for my train, a number of "high speed" trains come past. The light show, as well as noise, emitting from the collectors is rather spectacular.
My question is why does this only happen when it is cold and frost is about? The connection, I would imagine, is fairly good and you generally don't see sparks any other time. It cannot be a buildup of frost as it happens to two trains on the same line about 5 minutes apart. I would imagine that both train's collectors have pretty much the same track so it would not be about it running over a new frosty section.
TIA for any answers...