OVERHEAD CATENARY
http://www.forsten-online.de/content/05/03/seite1-en.htm
Energy Distribution on the New York, Westchester, & Boston Railway
http://www.nycsubway.org/nyc/nywb/nywb5.html
HEAVY ELECTRIC LAYOUTS
http://www.info-4u.com/modelmemories/heavyelect.htm#abramson