user: Question: What is the Gauge of Locomotive G534 Owned by Aurizon which has a Status of Operational?
Columns: ['Locomotive', 'Serial No', 'Entered service', 'Owner', 'Operator', 'Livery', 'Gauge', 'Status']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['G511', '84/1239', 'October 1984', 'Chicago Freight Car Leasing Australia', 'Southern Shorthaul Railroad', 'SSR yellow & black', 'Standard', 'Operational']
SQL:

assistant: SELECT "Gauge" FROM "Table" WHERE "Status" = 'Operational' AND "Owner" = 'Aurizon' AND "Locomotive" = 'G534';