4-8-8-2

Southern Pacific 4294, preserved at theCalifornia State Railroad Museumin Sacramento, California.

Under theWhyte notationfor the classification ofsteam locomotives,a4-8-8-2is a locomotive with fourleading wheels,two sets of eightdriving wheels,and a two-wheeltrailing truck.

Other equivalent classifications are:
UIC classification:2DD1(also known as German classification andItalian classification)
French classification:240+041
Turkish classification:46+45
Swiss classification:4/6+4/5

The equivalentUIC classificationis refined to(2'D)D1'for simple articulated locomotives.

A locomotive of that length must be anarticulated locomotive;meaning all have a joint between the first and second groups of driving wheels. All examples of this type arecab forwards.Normally, the leading truck sits under the smokebox and the trailing truck under the firebox. On a cab-forward, the leading truck supports the firebox and the trailing truck and smokebox are at the rear next to the tender. A 4-8-8-2 is effectively a2-8-8-4that always runs in reverse.

Southern Pacific

TheSouthern Pacificwas the only railroad to operate engines of this wheel arrangement, all of which were built by theBaldwin Locomotive Works.A total of 195 were produced between 1928 and 1944 in eight batches. The later ones had cylinders 24 inches by 32 inches, drivers 63-1/2 inches and boiler pressures of 250 psi, giving a calculated tractive effort of 123,400 lb.

The locomotives were built as cab-forwards to protect engine crews from exhaust smoke and heat in the many tunnels andsnow shedsthat were part of their usual routes.Although commonly calledMalletsthese cab-forwards were built with simple expansion cylinders. The name stuck because the original classes of Southern Pacific cab-forwards were built as compound Mallets, though these were eventually converted to simple expansion machines.

Southern Pacific 4294is the only cab forward that was not scrapped when the locomotives were withdrawn from service. It was donated to the City ofSacramento, Californiain 1958, but had to be moved due to freeway construction. It was given to the State of California and is on indoor static display at theCalifornia State Railroad Museumin Sacramento.

References

General reference

• Diebert, Timothy S. & Strapac, Joseph A. (1987).Southern Pacific Company Steam Locomotive Compendium.Shade Tree Books.ISBN0-930742-12-5.

External links

• Web Site of ToyTrains1 4-8-8-2 Cab Forward Steam Locomotives
• Steam Locomotive.com's Southern Pacific Cab Forward article, including detailed specs.