Articulated Steam Locomotives

Page Contents: [Famous and Well Known Articulated Steam Locomotives] [Exotic and Experimental Articulated Steam Locomotives] [Articulated Steam Locomotive References] [Other Articulated Steam Locomotive Web Sites]

This page will be a location where I will provide information about articulated locomotives that I have not already covered elsewhere in my site.

I am careful to use the word "articulated" instead of "mallet" to describe these locomotives. Periodically, I hear a Big Boy or Yellowstone referred to as a "Mallet" type locomotive. In my opinion, this is not true. Anatole Mallet designed a steam locomotive with two important characteristings. This locomotive

  1. was articulated, and
  2. used compound expansion (high and low pressure cylinders)
The Big Boys, Yellowstones, as well as many other articulated steam locomotives, used simple expansion (high pressure cylinders all around), and thus, according to the strictest definition of the term, are not true mallets.

Articulated locomotives such at the N&W Y class did use compound expansion and therefore are true "mallets".


Famous and Well Known Articulated Steam Locomotives

Railroad LineWheel ArrangementClassRoad NumbersQuantity
Norfolk & Western2-6-6-4A1200-124243
Union Pacific4-6-6-4CSA, 46643800-3839, 3950-3964, 3930-3999105
Chesapeake & Ohio2-6-6-6H-81600-165960
Norfolk & Western2-8-8-2Y995-999
1700-1730
2000-2109
2120-2200
227
Northern Pacific2-8-8-4Z-55000-501112
Southern Pacific2-8-8-4AC-93800-381112
Duluth, Missabe & Iron Range2-8-8-4M-3,4220-23718
Baltimore & Ohio2-8-8-4EM-17600-762930
Southern Pacific4-8-8-2AC-4-124100-4294195
Union Pacific4-8-8-44884-1,24000-402425

Exotic and Experimental Articulated Steam Locomotives

Railroad LineWheel ArrangementClassRoad NumbersQuantity
Atchison, Topeka & Santa Fevariousvarious  
Erie2-8-8-8-2P-15014-50163
Virginian2-8-8-8-4XA7001
Virginian2-10-10-2AE800-80910

Articulateds That Were Neither Famous Nor Exotic

Railroad LineWheel ArrangementClassRoad NumbersQuantity
Pennsylvaniavariousvarious  
St. Louis - San Francisco2-8-8-2none2001 - 2007 

Articulated Steam Locomotive References


Other Articulated Steam Locomotive Web Sites