CREATE TABLE table_6595 ("Locomotive" CLOB, "Delivered as" CLOB, "Entered service" CLOB, "Owner" CLOB, "Status" CLOB)

What is the Entered service date of the H1 Locomotive?
SELECT "Entered service" FROM table_6595 WHERE "Locomotive" = 'h1'
SELECT "Entered service" FROM "table_6595" WHERE "Locomotive" = 'h1'