Southern Pacific 4-10-2 No. 5046 poses at Colton, California in an undated image furnished by Carl Weber. The photographer's identity is also unspecified. When well maintained, despite the difficulty of adjusting the valve for the center cylinder, the SP 4-10-2s were good-running engines, but one of them experienced a lethal boiler explosion in 1946. Two examples of this rare three-cylinder type survive, one being Southern Pacific No. 5021 in Pomoma, California and the other being Baldwin demonstrator No. 60000 with a water-tube boiler that was never owned by a railroad but is preserved in the Franklin Institute in Philadelphia.