http://www.railways.incanada.net/candate/candate.htm
I found the site this morning, while I was looking for information on CP Rail's former - robot radio-command system...remote-controlled mid-train locomotives, see - November 16, 1967. During the early 70's - I frequently saw CP Rail trains operating with the robot-command system.
Nowadays, superior DPU technology controls multiple locomotives, in a train.
Perusing the timeline, I found something designated Z-1-a -
http://www.youtube.com/watch?v=eMDxG_D3We8
And while I was looking for Z-4-a and Z-5-a... I found this -
http://donsdepot.donrossgroup.net/dr2231.htm
the timeline also mentioned something I hadn't heard of - an EP-59a
http://www.flickr.com/photos/lionel682/8138752313/
Interesting site.
Rick