Ruby and I were laying in bed around midnight last night listening to the trains go by. It was very busy and we counted four trains in the space of about 10 minutes. There is a double Canadian Pacific mainline east/west, a double Canadian National mainline north/south and a single Canadian Pacific mainline north that wyes onto the double Canadian Pacific east/west line. Not to mention the various interchange tracks. Via Rail and GO Transit have trackage rights through the junction too.... The most common motive power in the area are GMD SD 40-2's owned by CP. There are also SD 90/43 MAC-H's and AC4400's. CN runs mostly GP 40-2C's and CW's which tend to chug. The first train to arrive stopped and waited for the other lines to clear before proceeding. It is very soothing to listen to the trains, but you have to make sure that the house is secure, or else you end up with things rattling as the trains go over the diamonds and frogs. As we lay listening to all the trains, I was trying to identify all of the sounds. The one train that spent the time idling while the other traffic cleared was humming nicely with a nice deisel whine. You could hear the air compressers and releaf valves chuffing happily. The one sound that I often hear from idling trains is a ticking or clicking sound. It sounds like an electrical discharge and I figure it has something to do with the capacitors discharging, but I don't know... Does anyone know what this sound is????