Question: Which Livery has a Description of 20T Tanker, with a date later than 1941?
SQL: SELECT "Livery" FROM "2-1174877-18" WHERE "Description" = '20T Tanker' AND "Date" > 1941.0;

Question: What's the Description for Scottish Tar Distillers No. 78, that's Livery is Black, and a date prior to 1897?
SQL: SELECT "Description" FROM "2-1174877-18" WHERE "Livery" = 'Black' AND "Date" < 1897.0 AND "Number & name" = 'Scottish Tar Distillers No. 78';