CREATE TABLE table_17015 ("Ships name" TEXT, "Entered service" TEXT, "Ended service" TEXT, "Gross Tonnage" FLOAT, "Type of Vessel" TEXT)

What was the gross tonnage of the ship that ended service in 1866?
SELECT "Gross Tonnage" FROM table_17015 WHERE "Ended service" = '1866'
SELECT "Gross Tonnage" FROM "table_17015" WHERE "Ended service" = '1866'