Alco 4-8-8-4 no. X4017 Big BoyPhotographed on 1 August 2003 at the National Railroad Museum, Green Bay, Wisconsin.
Built in 1941 by the American Locomotive Company for the Union Pacific Railroad, this is one of a batch of the heaviest steam locomotives ever built,weighing 772,000 lbs (386 tons). These engines were designed to be used in the Wasatch Mountains in the west, to avoid using helper (banking) engines.
The Big Boy is one of the best represented and preserved model of steam locomotive in the United States, due to its mythical reputation and late survival in service to 1959. Eight of the 25 built still exist.
Picture added on 23 November 2008
Boiler pressure:300psi
Cylinders:23.75x32in
Driving wheels:68in
Grate area:150.3sq ft
Heating surface:5889sq ft
Superheater;2466sq ft
Tractive effort:135,375lb
Total weight;350t(772,000lb)engine only.
These locomotives were built, to haul up to 70 refrigerated fruit cars, weighing 3,200 tons,over the road without assistance,a total of 25 were built,and could run at 80mph when required
Added by James Burrows on 02 October 2009.