Southern Pacific AC-11

E650375

The Southern Pacific AC-11 was a class of massive articulated cab-forward steam locomotives used by the Southern Pacific Railroad, primarily designed for heavy freight service over steep mountain grades.

All labels observed (3)

How this entity was disambiguated

Statements (44)

Predicate Object
instanceOf articulated locomotive class
steam locomotive class
brakeType air brakes
buildDate 1942
1943
builder Baldwin Locomotive Works
category 4-8-8-2 locomotives
Southern Pacific Railroad locomotives
articulated steam locomotives
cab-forward steam locomotives
oil-fired steam locomotives
configuration 4-8-8-2
country United States
cylinderArrangement simple articulated
cylinderCount 4
designer Southern Pacific Railroad
fuelType bunker oil
gauge 4 ft 8 1⁄2 in (1,435 mm)
notableFeature articulated frame
cab-forward design
designed for long tunnels and snow sheds
operatorRegion Cascade Range
Sierra Nevada
U.S. West Coast
United States
powerType steam
precededByClass Southern Pacific AC-10
preservedUnits 0
primaryRole heavy freight service
primaryRouteType mountain grades
railwayCompany Southern Pacific Transportation Company
railwayOperator Southern Pacific Railroad
retirementPeriod 1950s
roadNumberRange SP 4245
SP 4274
status all units scrapped
successorClass Southern Pacific AC-12
totalProduced 30
traction adhesion
UICClassification (2′D)D2′ h4
usedFor freight trains over Cascade Line
freight trains over Donner Pass
valveGear Walschaerts
whyCabForward to keep crew ahead of smoke in tunnels and snow sheds

How these facts were elicited

Referenced by (16)

Full triples — surface form annotated when it differs from this entity's canonical label.

AC-10 followedByClass Southern Pacific AC-11
AC-12 predecessorClass Southern Pacific AC-11
Southern Pacific AC-11 successorClass Southern Pacific AC-12
linked to: Southern Pacific AC-11
SP 4245 locomotiveClass Southern Pacific AC-11
SP 4245 series Southern Pacific AC-11 class
linked to: Southern Pacific AC-11
SP 4250 fleetOrClass Southern Pacific AC-11 class
linked to: Southern Pacific AC-11
SP 4260 class Southern Pacific AC-11
SP 4247 class Southern Pacific AC-11
SP 4263 class Southern Pacific AC-11
SP 4249 class Southern Pacific AC-11
SP 4267 class Southern Pacific AC-11
SP 4257 locomotiveClass Southern Pacific AC-11
SP 4257 partOfClass Southern Pacific AC-11 class
linked to: Southern Pacific AC-11
SP 4272 belongsToClass Southern Pacific AC-11 class
linked to: Southern Pacific AC-11
SP 4258 belongsToSeries Southern Pacific AC-11 class
linked to: Southern Pacific AC-11
SP 4277 class Southern Pacific AC-11