The first 2-8-0 was delivered to the Lehigh Valley in 1866 for operation over the mountain grades of the railroad's Mount Carmel Branch in Pennsylvania. The locomotive was built by Baldwin, but had been designed by the master mechanic of one of Lehigh Valley's predecessor railroads, the Lehigh & Mahanoy. The new design incorporated a self-centering radial engine truck that was equalized with the driving wheels to form a three-point suspension system. As a result, the 2-8-0 was a stable riding engine - much more so than the early 0-8-0s used in road service - and this made it capable of greater speeds. With eight coupled drivers, the 2-8-0 also had excellent adhesion.
The engine quickly proved itself on the Lehigh Valley and the railroad ordered fourteen copies. The first LV locomotive was named Consolidation - the same year it was introduced the Lehigh Valley completed a strategic merger with the Lehigh & Mahanoy - and this name was later applied to all 2-8-0 locomotives. Baldwin assembled Lehigh Valley 2-8-0 No. 310 in 1876 - the heaviest locomotive the firm had built up to that time - and displayed it at the Centennial International Exhibition in Philadelphia. The Consolidation turned out to be one of the all-time great locomotive designs. It could ably handle mountain grades, and a decade after its introduction it became the standard heavy freight engine.
Mountain railroads such as the Erie, Pennsylvania, and Baltimore & Ohio began replacing 4-4-0s with 2-8-0s in freight service. Compared to a 4-4-0, the 2-8-0 could pull trains that were twice as heavy at less cost. The widespread use of air brakes in the 1880s prompted railroads to run heavier trains, which the 2-8-0 proved more than capable of handling, further solidifying its position as America's preeminent freight locomotive.
Consolidations were built continuously into the 1920s and received the latest advances in steam locomotive technology, such as superheaters, stokers, feedwater heaters, piston valves, outside radial valve gear, and more. Driving wheel size increased steadily from 51 inches to 63 inches, which increased the engine's speed potential. By the time the last 2-8-0s were delivered in the 1940s, more than 33,000 had been delivered - more than any other type of steam locomotive built in the U.S. It was the diesel that ultimately vanquished the 2-8-0 from the rails. Many Consolidations remained active until the very end of steam.
So far as we know there were only two 2-8-0's in use along the coast and both of these – see pictures right – were in the employ of the CWR.