CREATE TABLE table_55007 ("Date" TEXT, "Ship" TEXT, "Type" TEXT, "Nationality" TEXT, "Tonnage GRT" FLOAT)

What type has a Date of 8 dec 16, and a Ship of duchess of cornwall?
SELECT "Type" FROM table_55007 WHERE "Date" = '8 dec 16' AND "Ship" = 'duchess of cornwall'
SELECT "Type" FROM "table_55007" WHERE "Date" = '8 dec 16' AND "Ship" = 'duchess of cornwall'