The 4300 4-8-2's : Southern Pacific's Mt-class locomotives
"The Allegheny was perhaps the finest high horsepower steam locomotive ever built which unfortunately never reached its full potential due to the arrival of the diesel engine. Although its size and potential is compared to the Union Pacific Big Boy, the Allegheny was not without controversy - which added to an inaccurate comparison of the two largest high horsepower steam locomotives. ..... " The Allegheny Lima's Finest
American Locomotives in Historic Photographs : 1858 to 1949 - by Ron Ziel ~ American Locomotives in Historic Photographs : 1858 to 1949