Table: avalon
Columns: ships_name
entered_service
ended_service
gross_tonnage
type_of_vessel

Question: What was the gross tonnage of the ship that ended service in 1866?
SQL: SELECT "gross_tonnage" FROM avalon WHERE "ended_service" = '1866'

Question: What is the minimum gross tonnage of the Munich? 
SQL: SELECT MIN("gross_tonnage") FROM avalon WHERE "ships_name" = 'Munich'