I wonder if this will help. I've posted links to an assortment of locomotives of various times. In general, in the USA, steam locomotives were used until the 1940s-50s when diesel locomotives became more popular.
a steam locomotive from the 19th to early 20th century: http://www.mapleridge.org/images/tourism/industry/steam_locomotive.jpg
a steam locomotive from approximately the 1930s-50s:
http://www.frisco1522.org/sm3qtr.jpg
an early diesel locomotive (1950):
http://www.ncstl.com/cities/kennesaw/NC F unit in Kennesaw.jpg
1970s era: http://pc.smellycat.com/pics/equip/pc6266.jpg
a GG-1 (the kind Green-elite-cab mentioned):
http://64.246.11.82/images/g/GG-1__4852__Nov_24_1968.jpg.50971.jpg
modern day diesel locomotive: http://www.microsoft.com/games/trainsimulator/img/article_DieselDash9.jpg
Does this give you an idea of the sort of time period and type of trains you are most interested in?
Regards,
Ralph
a steam locomotive from the 19th to early 20th century: http://www.mapleridge.org/images/tourism/industry/steam_locomotive.jpg
a steam locomotive from approximately the 1930s-50s:
http://www.frisco1522.org/sm3qtr.jpg
an early diesel locomotive (1950):
http://www.ncstl.com/cities/kennesaw/NC F unit in Kennesaw.jpg
1970s era: http://pc.smellycat.com/pics/equip/pc6266.jpg
a GG-1 (the kind Green-elite-cab mentioned):
http://64.246.11.82/images/g/GG-1__4852__Nov_24_1968.jpg.50971.jpg
modern day diesel locomotive: http://www.microsoft.com/games/trainsimulator/img/article_DieselDash9.jpg
Does this give you an idea of the sort of time period and type of trains you are most interested in?
Regards,
Ralph