The conversation between human and AI assistant.
[|Human|] Who designed the South African Class 15E 4-8-2 locomotive?
[|AI|] The designer of the South African Class 15E 4-8-2 locomotive was A.G. Watson, Chief Mechanical Engineer of the South African Railways.
[|Human|] 
Who designed the South African Class 15E 4-8-2 locomotive?