>>1769655Most of the non-articulated compounds in the US were either Cross-compound (One HP, one LP cylinder), Vauclain compound (2HP/2LP cylinders, mounted on top of each other like pic), or Tandem compound (Again 2HP/2LP, but mounted in front of each other.)
They were sorta popular for 1890-1910, but were almost completely dropped after that. American lines were seriously opposed to cylinders between the frames, so even the 4-cylinder locos as described above tried to keep them all on the outside; the main exception being the 3-cylinder 4-10-2s and 4-12-2s, but those were simple expansion anyway.
The Vauclains and tandems sorta worked, but had uneven stresses that were not present in multi-cylinder compounds that put some cylinders inside the frames, such as the de-Glehn type that was extremely successful in France (And some UK locos used a simple-expansion version)
