A Prussic knot came to the rescue of Buckingham Palace's Union Jack after it became tangled around its flag pole last Friday. The special Germanic slip-knot allowed abseiler and ex-royal engineer James Shalcross from roped access specialist CAN to shin up the Palace flagpole using foot-slings. Within minutes he had unwrapped the unfluttering emblem which had become snared on the decorative crown on the pole. CAN has unwrapped Parliament's flag three times in the last few years and so was the obvious choice for the palace job, particularly as its team is surveying the nearby Blackfriars Bridge. The Queen was not at home during the rescue.