It is June and staff at the Tower are bringing out the big guns to celebrate the anniversary of Elizabeth II's coronation in 1953. A massive 62-gun salute is planned on the Wharf, but with his boss, the Chief Yeoman Warder, away, new Yeoman Gaoler Rob Fuller is in charge for the first time. Three 4,000lb guns and thousands of visitors to contend with mean the pressure's on Rob to get it right