The 4HH4HH4HH4m32tyf Class is a class of extremely large articulated locomotives designed by Conan Diedrich at the Eastern & Atlantic's Charlotte Works.


The Eastern & Atlantic's heavily graded lines in Virginia, Tennesse and West Virginia often required many heavy bankers or double or triple-headed trains to tackle them. Thus, after the Second World War, Conan Diedrich decided to design the then largest locomotive on earth, a huge hexaplex with six sets of driving wheels. The hexaplex locomotive had two boilers like the earlier 4HHHH4m19y Class, however this class had a coal bunker in the rear and a water tank in the front of the locomotive in the manner of a Garratt locomotive, which allowed the locomotives to go around tighter curves than could be managed with a regular mallet locomotive.

2 locomotives were built in 1946.