AC-5
E163094
Southern Pacific Railroad locomotive class
cab-forward articulated locomotive class
steam locomotive class
AC-5 was a class of Southern Pacific Railroad cab-forward articulated steam locomotives built in the late 1920s for heavy freight service over mountainous routes.
All labels observed (2)
How this entity was disambiguated
This entity first appeared as the object of triple T1422813 — 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: AC-5 Context triple: [Southern Pacific Cab Forward locomotive, classificationBySP, AC-5]
-
A.
C-5
C-5 is a commuter rail line in the Cercanías Madrid network that connects central Madrid with several western suburbs and outlying municipalities.
-
B.
CT-156 Harvard II
The CT-156 Harvard II is a turboprop military trainer aircraft used by the Royal Canadian Air Force for pilot training and skill development.
-
C.
Alpha Jet
The Alpha Jet is a light attack and advanced jet trainer aircraft developed jointly by France and Germany in the 1970s and widely used for pilot training and tactical support roles.
-
D.
M-45
M-45 is a state highway in Michigan that runs east–west through the Grand Rapids area toward the Lake Michigan shoreline.
-
E.
Blackhawk
Blackhawk is the athletic and school spirit mascot representing Springs Valley High School’s teams and student body.
- 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: AC-5 Target entity description: AC-5 was a class of Southern Pacific Railroad cab-forward articulated steam locomotives built in the late 1920s for heavy freight service over mountainous routes.
-
A.
C-5
C-5 is a commuter rail line in the Cercanías Madrid network that connects central Madrid with several western suburbs and outlying municipalities.
-
B.
CT-156 Harvard II
The CT-156 Harvard II is a turboprop military trainer aircraft used by the Royal Canadian Air Force for pilot training and skill development.
-
C.
Alpha Jet
The Alpha Jet is a light attack and advanced jet trainer aircraft developed jointly by France and Germany in the 1970s and widely used for pilot training and tactical support roles.
-
D.
M-45
M-45 is a state highway in Michigan that runs east–west through the Grand Rapids area toward the Lake Michigan shoreline.
-
E.
Blackhawk
Blackhawk is the athletic and school spirit mascot representing Springs Valley High School’s teams and student body.
- F. None of above. chosen
Statements (30)
| Predicate | Object |
|---|---|
| instanceOf |
Southern Pacific Railroad locomotive class
ⓘ
cab-forward articulated locomotive class ⓘ steam locomotive class ⓘ |
| articulationType | Mallet-type articulated ⓘ |
| buildDate | late 1920s ⓘ |
| builder | Baldwin Locomotive Works ⓘ |
| configuration | cab-forward ⓘ |
| country |
United States
ⓘ
linked to:
United States of America
|
| designedFor |
long, heavy trains
ⓘ
mountain grades ⓘ |
| era | steam era ⓘ |
| followedBy | later Southern Pacific AC classes ⓘ |
| gauge | standard gauge ⓘ |
| hasFeature |
articulated engine units
ⓘ
forward-mounted cab ⓘ tender at rear ⓘ |
| locomotiveClassFamily |
Southern Pacific AC cab-forward classes
ⓘ
linked to:
Southern Pacific Cab Forward locomotive
|
| operator | Southern Pacific Railroad ⓘ |
| powerType | steam ⓘ |
| precededBy | earlier Southern Pacific AC classes ⓘ |
| primaryUse | freight service ⓘ |
| railroad |
Southern Pacific
ⓘ
linked to:
Southern Pacific Railroad
|
| railroadRegion |
Western United States
ⓘ
linked to:
western United States
|
| railwayCompany |
Southern Pacific Company
ⓘ
linked to:
Southern Pacific Railroad
|
| railwayOperator | Southern Pacific Railroad ⓘ |
| routeType | mountainous routes ⓘ |
| safetyRationale | cab-forward design to reduce crew exposure to smoke in tunnels and snow sheds ⓘ |
| serviceType | heavy freight ⓘ |
| usedFor | mountainous freight operations ⓘ |
| usedOn | Southern Pacific mainline freight routes ⓘ |
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: AC-5 Description of subject: AC-5 was a class of Southern Pacific Railroad cab-forward articulated steam locomotives built in the late 1920s for heavy freight service over mountainous routes.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: AC-5