user: Question: What is the highest tonnage for a ship from Great Britain named Newton Ash?
Columns: ['Date', 'Ship', 'Nationality', 'Tonnage', 'Fate']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['16 May 1941', 'Llangibby Castle', 'Great Britain', 11951.0, 'Damaged']
SQL:

assistant: SELECT MAX("Tonnage") FROM "Table" WHERE "Nationality" = 'Great Britain' AND "Ship" = 'Newton Ash';