Locomotive, Steam, Cab Forward

History: The cab forward design was widely used by the Southern Pacific Railroad. The design was able to deal with the peculiar problems of its routes. The 39 long tunnels and nearly 40 miles (64 km) of snow sheds of the Sierra Nevada Mountains could funnel dangerous exhaust fumes back into the crew compartment of a conventional locomotive. After a number of crews nearly asphyxiated, the locomotive was run in reverse. This meant that the tender was leading the train, which introduced new problems. The tender blocked the view ahead and put crewmen on the wrong sides of the cab for seeing signals. The tenders were not designed to be pushed at the lead of the train, which limited speeds. Southern Pacific commissioned Baldwin Locomotive Works to build a prototype cab-forward locomotive, then ordered more units before the prototype had even arrived.

All of the cab-forwards were oil-burning locomotives, which meant there was little trouble involved putting the tender at what would normally be the front of the locomotive. The oil and water tanks were pressurized so that both would flow normally even on uphill grades. Visibility from the cab was superb, such that one crewman could easily survey both sides of the track. There were concerns about what would happen to the crew in the event of a collision, and at least one fatal accident occurred on the Modoc Line in Herlong, California when a moving locomotive struck a flat car.[4] Turning the normal locomotive arrangement around also placed the crew well ahead of the exhaust fumes, insulating them from that hazard. One problematic aspect of the design, however, was the routing of the oil lines; because the firebox was located ahead of the driving wheels (instead of behind them, the usual practice), oil leaks could cause the wheels to slip. A nuisance under most conditions, it resulted in at least one fatal accident. This occurred in 1941 when a cab-forward with leaking steam and oil lines entered the tunnel at Santa Susana Pass, near Los Angeles. The tunnel was on a grade, and as the slow-moving train ascended the tunnel, oil on the rails caused the wheels to slip and spin. The train slipped backwards and a coupler knuckle broke, separating the air line, causing an emergency brake application and stalling the train in a tunnel that was rapidly filling with exhaust fumes and steam. The oil dripping on the rails and ties then ignited beneath the cab, killing the crew.

No other North American railroad ordered cab-forward locomotives, although some, like Western Pacific, did consider the type. Built to deal with difficult terrain, these locomotives became an easily recognizable symbol of the Southern Pacific. In total 256 such Mallet-type articulated locomotives, in three different wheel arrangements, were placed on SP's roster. One example of the type, Southern Pacific 4294, is kept at the California State Railroad Museum in Sacramento, California. It is a 4-8-8-2 locomotive and is the only one to escape being scrapped. It was also SP's last new steam locomotive, built in 1944.

From Wikipedia

Railroad/Company: The Baldwin Locomotive Works was an American builder of railroad locomotives. It was originally located in Philadelphia, and later moved to nearby Eddystone, Pennsylvania. Although the company was very successful as the largest producer of steam locomotives, its transition to the production of diesels was far less so. Later, when the early demand for diesel locomotives to replace steam tapered off, Baldwin could not compete in the marketplace. It stopped producing locomotives in 1956 and went out of business in 1972, having produced over 70,000 locomotives, the vast majority powered by steam.

In 1956, after 125 years of continuous locomotive production, Baldwin closed most of its Eddystone plant and ceased producing locomotives. The company instead concentrated on production of heavy construction equipment. More than 70,500 locomotives had been built when production ended. In 1965 Baldwin became a wholly owned subsidiary of Armour and Company. Greyhound Corporation purchased Armour and Company in 1970, and in 1972 Greyhound closed Baldwin-Lima-Hamilton for good.

From Wikipedia