Table: prr_locomotives
Columns: prr_class
builder_s_model
build_date
total_produced
wheel_arrangement
service
power_output

Question: Who built the train in 1966 with over 40 produced?
SQL: SELECT "builder_s_model" FROM prr_locomotives WHERE "total_produced" > 40 AND "build_date" = '1966'

Question: What is the PRR class of the freight train built in 1967 with a b-b wheel arrangement?
SQL: SELECT "prr_class" FROM prr_locomotives WHERE "wheel_arrangement" = 'b-b' AND "service" = 'freight' AND "build_date" = '1967'

Question: What PRR class has a Wheel arrangement of a1a-a1a?
SQL: SELECT "prr_class" FROM prr_locomotives WHERE "wheel_arrangement" = 'a1a-a1a'