CREATE TABLE table_56086 ("Class" CLOB, "Wheels" CLOB, "Date" CLOB, "No. built" FLOAT, "Loco Nos." CLOB, "Comments" CLOB)

Which class at 55 built?
SELECT "Class" FROM table_56086 WHERE "No. built" = '55'
SELECT "Class" FROM "table_56086" WHERE "No. built" = '55'