user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: what is the name of the locomotive that is owned by southern pacific railroad? 
Knowledge Triplets: Collis Potter Huntington, organization.organization_founder.organizations_founded, Southern Pacific Transportation Company
m.047kqcw, business.employment_tenure.company, Southern Pacific Transportation Company
Collis Potter Huntington, symbols.name_source.namesakes, Huntington Hotel
Huntington Park, symbols.namesake.named_after, Collis Potter Huntington
m.0j9jqm_, type.object.permission, m.019h
Chesapeake and Ohio Railway, organization.organization.founders, Collis Potter Huntington
Collis Potter Huntington, symbols.name_source.namesakes, Collis P. Huntington State Park
Southern Pacific Transportation Company, organization.organization.leadership, m.0fpsc3z
Collis Potter Huntington, book.book_subject.works, Nothing Like It in the World: The Men Who Built the Transcontinental Railroad 1863-1869
m.052b88z, business.employment_tenure.company, Southern Pacific Transportation Company
Bakersfield, metropolitan_transit.transit_stop.terminus_for_lines, Southern Pacific Transportation Company
Southern Pacific Transportation Company, metropolitan_transit.transit_line.terminuses, Bakersfield
m.0zncylr, rail.locomotive_ownership.owner, Southern Pacific Transportation Company
Southern Pacific Transportation Company, business.employer.employees, m.04gdcfv
Southern Pacific Transportation Company, business.employer.employees, m.0wl40ds
Southern Pacific Transportation Company, business.employer.employees, m.05lzzxy
Southern Pacific Transportation Company, organization.organization.board_members, m.04hdxt3
m.05pwc28, organization.organization_board_membership.organization, Southern Pacific Transportation Company
Southern Pacific Transportation Company, organization.organization.headquarters, m.0pdj4s5
m.019h, type.permission.controls, m.0j9jqm_
Collis Potter Huntington, book.author.works_written, Collis P. Huntington papers, 1856-1901
Southern Pacific Transportation Company, business.employer.employees, m.047kqcw
m.0zncylr, rail.locomotive_ownership.locomotive, Southern Pacific 2579
Southern Pacific Transportation Company, organization.organization.founders, Collis Potter Huntington
m.0bx2vm4, business.employment_tenure.company, Southern Pacific Transportation Company
California, location.location.contains, Bakersfield
Southern Pacific Transportation Company, business.employer.employees, m.047kqd2
Collis P. Huntington State Park, symbols.namesake.named_after, Collis Potter Huntington
Collis Potter Huntington, symbols.name_source.namesakes, Huntington Park
Huntington Ingalls Industries, symbols.namesake.named_after, Collis Potter Huntington
Collis Potter Huntington, book.author.works_written, The Colton letters
Huntington, symbols.namesake.named_after, Collis Potter Huntington
The Colton letters, book.written_work.author, Collis Potter Huntington
Southern Pacific Transportation Company, business.employer.employees, m.047kqcm
Southern Pacific Transportation Company, base.schemastaging.context_name.pronunciation, g.125_lhw45
m.047kqd2, business.employment_tenure.company, Southern Pacific Transportation Company
Northrop Grumman Shipbuilding, organization.organization.founders, Collis Potter Huntington
Darius Ogden Mills, business.board_member.leader_of, m.0fpsc3z
Central Pacific Railroad, organization.organization.founders, Collis Potter Huntington
m.04gdcfv, business.employment_tenure.company, Southern Pacific Transportation Company
Southern Pacific 2579, rail.locomotive.owners, m.0zncylr
Southern Pacific Transportation Company, business.employer.employees, m.0bx2vm4
Collis Potter Huntington, symbols.name_source.namesakes, Huntington
Southern Pacific Transportation Company, organization.organization.board_members, m.05pwc2h
m.06h_8hr, base.yupgrade.user.topics, Southern Pacific Transportation Company
Collis P. Huntington papers, 1856-1901, book.written_work.author, Collis Potter Huntington
Bakersfield, location.location.containedby, Bakersfield
Bakersfield, location.location.containedby, California
m.0fpsc3z, organization.leadership.organization, Southern Pacific Transportation Company
Southern Pacific Transportation Company, business.employer.employees, m.052b88z
m.0j9jqm_, dataworld.gardening_hint.last_referenced_by, Southern Pacific Transportation Company
Bakersfield, location.location.contains, Bakersfield
Southern Pacific Transportation Company, rail.locomotive_owner.locomotives_owned, m.0zncylr
Collis Potter Huntington, symbols.name_source.namesakes, Huntington Ingalls Industries
m.04hdxt3, organization.organization_board_membership.organization, Southern Pacific Transportation Company
m.0zncylr, rail.locomotive.owners, Southern Pacific 2579
m.05lzzxy, business.employment_tenure.company, Southern Pacific Transportation Company
m.05pwc2h, organization.organization_board_membership.organization, Southern Pacific Transportation Company
m.0wl40ds, business.employment_tenure.company, Southern Pacific Transportation Company
m.06wft1x, base.yupgrade.user.topics, Southern Pacific Transportation Company
m.047kqcm, business.employment_tenure.company, Southern Pacific Transportation Company
Huntington Hotel, symbols.namesake.named_after, Collis Potter Huntington
m.0zncylr, rail.locomotive_ownership.to_date, 1957
Southern Pacific Transportation Company, user.avh.default_domain.ellerdale_topic.ellerdale_id, 009b-3174
Southern Pacific Transportation Company, organization.organization.board_members, m.05pwc28

Answer: Southern Pacific 2579