user: Question: What is the Cargo ship located at Birkenhead?
Columns: ['Country', 'Builder', 'Location', 'Ship', 'Class / type']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['United States', 'Bath Iron Works', 'Bath, Maine', 'Mitscher', 'Mitscher-class destroyer']
SQL:

assistant: SELECT "Ship" FROM "Table" WHERE "Class / type" = 'Cargo ship' AND "Location" = 'Birkenhead';