4-10-2 (Southern Pacific or Overland) Type Locomotives

The 4-10-2 was the logical evolution of the successful 2-10-2 and ALCO's push for three-cylinder steam. The additional weight of the third cylinder and valve gear in the front of a locomotive required a four-wheel lead truck. In 1925 ALCO built two similar 4-10-2s and had the Southern Pacific and Union Pacific try them out. On the SP, they called this wheel arrangement "Southern Pacific". On the UP, they called this wheel arrangement "Overland". Southern Pacific liked the 4-10-2s and by 1927 had 49 of them. The Union Pacific had moderate success and owned 10. The UP seemed to prefer their 4-12-2s. In 1926 Baldwin built a three-cylinder 4-10-2 with a watertube firebox which traveled around the country as a demonstrator model. It was numbered 60000 (the 60000th locomotive that Baldwin built. It didn't catch on and was placed in the Franklin Institute in 1932 where it remains today. This would be the only 4-10-2 that Baldwin would build. It would also be in extremely good shape.

USA and Canadian Railroads that used 4-10-2 (Southern Pacific or Overland) Type Locomotives

Surviving Examples of 4-10-2 (Southern Pacific or Overland) Type Locomotives

No.ClassF.M. WhyteGaugeRailroad LineLocationStatusBuilder InformationNotes
5021SP-24-10-24'-8½"SP Los Angeles Co. Fairplex, Pomona, CAdisplayALCO (Schenectady) #66793, 1926Three cylinder
600004-10-24'-8½"Baldwin Franklin Institute Science Museum, Philadelphia, PAmoving displayBaldwin #60000, 1926 Three cylinder

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