The Pittsburgh & West Virginia pioneered the 2-6-6-4 type of simple articulated with the three members of the J-1 class that Baldwin Locomotive Works delivered in 1934. They rolled on 64-inch drivers, sustained 225 p.s.i. of boiler pressure, and had four cylinders measuring 23x32 inches. Designed to meet the bridge railroad's need for faster train speeds, as part of the "Alphabet Route", they had a large Belpaire firebox of more than 102 square feet, plus 5914 square feet of evaporative heating surface and 1873 square feet of superheating surface. They exerted 101,171 pounds of tractive effort and weighed 528,040 pounds. As this Baldwin builder's photo of No. 1101 shows, the J-1 class was equipped with a tender booster which was omitted in the succeeding J-2 class of four engines. Only three other railroads used the 2-6-6-4 type. The Seaboard Air Line sold its ten to the Baltimore & Ohio in 1947; but it was the Norfolk & Western which perfected the design into its famous class A, of which No. 1218 remains the sole survivor of the 2-6-6-4 type.