CREATE TABLE table_56696 ("PRR Class" CLOB, "Builderpars_m_singles Model" CLOB, "Build date" CLOB, "Total produced" FLOAT, "Wheel arrangement" CLOB, "Service" CLOB, "Power output" CLOB)

What is the power of b-b wheel arrangement, built in 1952?
SELECT "Power output" FROM table_56696 WHERE "Wheel arrangement" = 'b-b' AND "Build date" = '1952'
SELECT "Power output" FROM "table_56696" WHERE "Build date" = '1952' AND "Wheel arrangement" = 'b-b'