I should perhaps add that the arcs only occurs when the line is covered in ice. But as this is the case a good many mornings during the winter and the trains doesn't seem to have a problem with it I became curious.
Several other things fail because of the ice and snow: The switches freeze (despite the electrical heating) and moving parts in the undercarriage of the train jam. (Only last night was my train delayed 20 minutes due to a switch problem) Last winter the trains looked like balls of ice when they rolled into the station. If they maintenance crew managed to get them rolling at all, that is.
(New trains were ordered early this year: the spec calls for operating temperatures down to -35°C (about the same in °F))
Trainwire: I've got another question. When the trains here derail, they have on at least two occasions in last three years torn down the wire too. I can't see how the "tap" (what is it called?) can tear the wire down. Can you explain how this happens?
