Southern Pacific class MC-2

Infobox Locomotive
name=Southern Pacific class MC-2
powertype=Steam
railroad=Southern Pacific Railroad
gauge=4 ft 8½ in (1435 mm)
railroadclass=MC-2
driversize=57 in diameter
hpcylindersize=26 in dia × 30 in stroke
lpcylindersize=40 in dia × 30 in stroke
weight=437,000 lb
weightondrivers=394,700 lb
boilerpressure=200 psi
tractiveeffort=94,880 lbf
roadnumber=4002 – 4016
builder=Baldwin Locomotive Works
serialnumber=34019, 34043, 34044, 34046, 34047, 34063-34067, 34093-34097
builddate=November-December 1909
firstrundate=February 4 1910
retiredate=1946 – 1948
disposition=scrapped
whytetype=2-8-8-2
numinclass=15
fueltype=oil

Southern Pacific Railroad's MC-2 class of steam locomotives was the first class to be ordered by and built for Southern Pacific (SP) as cab forward locomotives. They were built in 1909 following the design of SP's MC-1 class built earlier that year. The success of this locomotive model led to the design and introduction of the AC class of 4-8-8-2 cab forward locomotives in the 1930s and 1940s.

In order to get the fuel oil from the tender to the opposite end of the locomotive where the firebox sat, SP had to pressurize the oil in the tender. Five pounds-force per square inch (35 kPa) of air pressure was sufficient to get the oil to the fire.

The two MC-1 locomotives built in May 1909 were rebuilt in 1923 as MC-2 class with uniform cylinders measuring 22 in diameter × 30 in stroke; these rebuilt locomotives weighed 437,000 lb, like the as-built MC-2 class, but with 393,700 lb on the drivers. Most of the rest of the MC-2 class were "simpled" to the same size cylinders by 1931. Except for numbers 4011 and 4013 which were both scrapped by 1936, all of the MC-2 and the two former MC-1 locomotives were rebuilt again into class AC-1 with a higher boiler pressure, but a lower overall tractive effort. The MC-2 rebuilds included installation of a new 4¼-BL Worthington feedwater heater as well.

SP used these locomotives until after World War II, retiring and then scrapping them in 1947 and 1948. The last locomotive of this class was scrapped on April 12 1949, at SP's Sacramento shops.

References

*
* Percy, Richard A. (2005), " [http://espee.railfan.net/sp_steam_mc-02.html Southern Pacific 'Cab Forward' Class MC-2] ". Retrieved January 23 2006.