CN 461-20 is a specialized hi-rail crane. Although you cannot see it in the photo, he's actually standing on rail. I've only seen a similar machine since once, CN 461-13 at the Portage JCT MOW shops (Winnipeg) later that year.
Couple years later a fellow Saskatoon Railfan, Elijah, caught it here in town @ Riverview:
http://tinyurl.com/2uzt7w
This is one of my earliest Railway photos. As part of our Grade 11 History class we went to the Forks Downtown, naturally I snack out to VIA's Union station.