Which 1947 Nos has a BR Nos of 48730-9?
CREATE TABLE "construction" (
  "1946_nos" text,
  "1947_nos" text,
  "date" real,
  "built_at" text,
  "lms_nos" text,
  "br_nos" text
);
SELECT "1947_nos" FROM "construction" WHERE "br_nos"='48730-9';