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 (1)
| Label | Occurrences |
|---|---|
| Southern Pacific AC-11 canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T7196548 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Southern Pacific AC-11 Context triple: [AC-10, followedByClass, Southern Pacific AC-11]
-
A.
Southern Pacific AC-9
The Southern Pacific AC-9 was a class of massive articulated 2-8-8-4 steam locomotives built in the late 1930s for the Southern Pacific Railroad, primarily used for heavy freight service across challenging western routes.
-
B.
Convair 440
The Convair 440 is a twin-engine, short- to medium-range commercial airliner developed in the 1950s as an improved, pressurized variant of Convair’s successful series of piston-powered passenger aircraft.
-
C.
Fairchild C-82 Packet
The Fairchild C-82 Packet was an American twin-boom, twin-engine military transport aircraft developed during World War II for cargo and paratroop operations.
-
D.
Boeing Air Transport
Boeing Air Transport was an early American airline and a predecessor of United Airlines that operated mail and passenger services in the late 1920s and early 1930s.
-
E.
Douglas DC-5
The Douglas DC-5 is a twin-engine, short-haul airliner developed in the late 1930s, notable as one of the earliest commercial aircraft with a high-wing design and tricycle landing gear.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Southern Pacific AC-11 Target entity description: 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.
-
A.
Southern Pacific AC-9
The Southern Pacific AC-9 was a class of massive articulated 2-8-8-4 steam locomotives built in the late 1930s for the Southern Pacific Railroad, primarily used for heavy freight service across challenging western routes.
-
B.
Convair 440
The Convair 440 is a twin-engine, short- to medium-range commercial airliner developed in the 1950s as an improved, pressurized variant of Convair’s successful series of piston-powered passenger aircraft.
-
C.
Fairchild C-82 Packet
The Fairchild C-82 Packet was an American twin-boom, twin-engine military transport aircraft developed during World War II for cargo and paratroop operations.
-
D.
Boeing Air Transport
Boeing Air Transport was an early American airline and a predecessor of United Airlines that operated mail and passenger services in the late 1920s and early 1930s.
-
E.
Douglas DC-5
The Douglas DC-5 is a twin-engine, short-haul airliner developed in the late 1930s, notable as one of the earliest commercial aircraft with a high-wing design and tricycle landing gear.
- F. None of above. chosen
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
articulated locomotive class
ⓘ
steam locomotive class ⓘ |
| brakeType | air brakes ⓘ |
| buildDate |
1942
ⓘ
1943 ⓘ |
| builder | Baldwin Locomotive Works NERFINISHED ⓘ |
| category |
4-8-8-2 locomotives
ⓘ
Southern Pacific Railroad locomotives NERFINISHED ⓘ articulated steam locomotives ⓘ cab-forward steam locomotives ⓘ oil-fired steam locomotives ⓘ |
| configuration | 4-8-8-2 ⓘ |
| country |
United States of America
ⓘ
surface form:
United States
|
| cylinderArrangement | simple articulated ⓘ |
| cylinderCount | 4 ⓘ |
| designer | Southern Pacific Railroad NERFINISHED ⓘ |
| 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
NERFINISHED
ⓘ
Sierra Nevada NERFINISHED ⓘ U.S. West Coast NERFINISHED ⓘ United States NERFINISHED ⓘ |
| powerType | steam ⓘ |
| precededByClass | Southern Pacific AC-10 NERFINISHED ⓘ |
| preservedUnits | 0 ⓘ |
| primaryRole | heavy freight service ⓘ |
| primaryRouteType | mountain grades ⓘ |
| railwayCompany | Southern Pacific Transportation Company NERFINISHED ⓘ |
| railwayOperator | Southern Pacific Railroad NERFINISHED ⓘ |
| retirementPeriod | 1950s ⓘ |
| roadNumberRange |
SP 4245
NERFINISHED
ⓘ
SP 4274 NERFINISHED ⓘ |
| status | all units scrapped ⓘ |
| successorClass | Southern Pacific AC-12 NERFINISHED ⓘ |
| totalProduced | 30 ⓘ |
| traction | adhesion ⓘ |
| UICClassification | (2′D)D2′ h4 ⓘ |
| usedFor |
freight trains over Cascade Line
ⓘ
freight trains over Donner Pass ⓘ |
| valveGear | Walschaerts NERFINISHED ⓘ |
| whyCabForward | to keep crew ahead of smoke in tunnels and snow sheds ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Southern Pacific AC-11 Description of subject: 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.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.