Which of the lowest years had a Wheel arrangement that was 0-4-2t?
CREATE TABLE "locomotives_of_the_southern_railway" (
  "iwcr_no" text,
  "name" text,
  "wheel_arrangement" text,
  "sr_no" text,
  "year_made" real,
  "year_withdrawn" real
);
SELECT MIN("year_made") FROM "locomotives_of_the_southern_railway" WHERE "wheel_arrangement"='0-4-2t';