Name the category for cab size crew and super tanker
CREATE TABLE "table1_2155350_2" (
  "category" text,
  "sub_category" text,
  "cab_size" text,
  "drive_wheels" text,
  "capacity_litres" text
);
SELECT "category" FROM "table1_2155350_2" WHERE "cab_size"='Crew' AND "sub_category"='Super tanker';