CREATE TABLE table_54800 ("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 build date for PRR Class gf30a?
SELECT "Build date" FROM table_54800 WHERE "PRR Class" = 'gf30a'
SELECT "Build date" FROM "table_54800" WHERE "PRR Class" = 'gf30a'