Read this: Thus, Buckingham Palace is a symbol and home of the British monarchy, an art gallery and a tourist attraction. Behind the gilded railings and gates which were completed by the Bromsgrove Guild in 1911 and Webb's famous façade, which has been described in a book published by the Royal Collection as looking "like everybody's idea of a palace", is not only a weekday home of the Queen and Prince Philip but also the London residence of the Duke of York and the Earl and Countess of Wessex. The palace also houses the offices of the Queen, Prince Philip, Duke of York, Earl and Countess of Wessex, Princess Royal, and Princess Alexandra, and is the workplace of more than 800 people.

In what year were the railings and gates completed?
What is the answer? (If it cannot be answered, return "unanswerable")
1911