CREATE TABLE table_68468 ("Class" TEXT, "Type" TEXT, "Fleet numbers" TEXT, "Quantity made" FLOAT, "Manufacturer" TEXT, "Date made" FLOAT, "Date withdrawn" TEXT)

Which manufacturer made a locomotive with a type of 4-6-4t?
SELECT "Manufacturer" FROM table_68468 WHERE "Type" = '4-6-4t'
SELECT "Manufacturer" FROM "table_68468" WHERE "Type" = '4-6-4t'